1
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Donker N, Schönauer-Kamin D, Moos R. Mixed-Potential Ammonia Sensor Based on a Dense Yttria-Stabilized Zirconia Film Manufactured at Room Temperature by Powder Aerosol Deposition. SENSORS (BASEL, SWITZERLAND) 2024; 24:811. [PMID: 38339528 PMCID: PMC10857374 DOI: 10.3390/s24030811] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Revised: 01/19/2024] [Accepted: 01/22/2024] [Indexed: 02/12/2024]
Abstract
Powder aerosol deposition (often abbreviated as PAD, PADM, or ADM) is a coating method used to obtain dense ceramic films at room temperature. The suitability of this method to obtain ammonia mixed-potential sensors based on an yttria-stabilized zirconia (YSZ) electrolyte that is manufactured using PAD and a V2O5-WO3-TiO2 (VWT)-covered electrode is investigated in this study. The sensor characteristics are compared with data from sensors with screen-printed YSZ solid electrolytes. The PAD sensors outperform those in terms of sensitivity with 117 mV/decade NH3 compared to 88 mV/decade. A variation in the sensor temperature shows that the NH3 sensitivity strongly depends on the sensor temperature and decreases with higher sensor temperature. Above 560 °C, the characteristic curve shifts from exponential to linear dependency. Variations in the water and the oxygen content in the base gas (usually 10% oxygen, 2% water vapor in nitrogen) reveal a strong dependence of the characteristic curve on the oxygen content. Water vapor concentration variations barely affect the sensor signal.
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Affiliation(s)
| | | | - Ralf Moos
- Department of Functional Materials, University of Bayreuth, Universitätsstraße 30, 95440 Bayreuth, Germany
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2
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Wang Y, Tong C, Liu Q, Han R, Liu C. Intergrowth Zeolites, Synthesis, Characterization, and Catalysis. Chem Rev 2023; 123:11664-11721. [PMID: 37707958 DOI: 10.1021/acs.chemrev.3c00373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/16/2023]
Abstract
Microporous zeolites that can act as heterogeneous catalysts have continued to attract a great deal of academic and industrial interest, but current progress in their synthesis and application is restricted to single-phase zeolites, severely underestimating the potential of intergrowth frameworks. Compared with single-phase zeolites, intergrowth zeolites possess unique properties, such as different diffusion pathways and molecular confinement, or special crystalline pore environments for binding metal active sites. This review first focuses on the structural features and synthetic details of all the intergrowth zeolites, especially providing some insightful discussion of several potential frameworks. Subsequently, characterization methods for intergrowth zeolites are introduced, and highlighting fundamental features of these crystals. Then, the applications of intergrowth zeolites in several of the most active areas of catalysis are presented, including selective catalytic reduction of NOx by ammonia (NH3-SCR), methanol to olefins (MTO), petrochemicals and refining, fine chemicals production, and biomass conversion on Beta, and the relationship between structure and catalytic activity was profiled from the perspective of intergrowth grain boundary structure. Finally, the synthesis, characterization, and catalysis of intergrowth zeolites are summarized in a comprehensive discussion, and a brief outlook on the current challenges and future directions of intergrowth zeolites is indicated.
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Affiliation(s)
- Yanhua Wang
- Tianjin Key Laboratory of Indoor Air Environmental Quality Control, School of Environmental Science and Engineering, Tianjin University, Tianjin 300350, China
- State Key Laboratory of Engines, Tianjin University, Tianjin 300072, China
| | - Chengzheng Tong
- Tianjin Key Laboratory of Indoor Air Environmental Quality Control, School of Environmental Science and Engineering, Tianjin University, Tianjin 300350, China
- State Key Laboratory of Engines, Tianjin University, Tianjin 300072, China
| | - Qingling Liu
- Tianjin Key Laboratory of Indoor Air Environmental Quality Control, School of Environmental Science and Engineering, Tianjin University, Tianjin 300350, China
- State Key Laboratory of Engines, Tianjin University, Tianjin 300072, China
| | - Rui Han
- Tianjin Key Laboratory of Indoor Air Environmental Quality Control, School of Environmental Science and Engineering, Tianjin University, Tianjin 300350, China
- State Key Laboratory of Engines, Tianjin University, Tianjin 300072, China
| | - Caixia Liu
- Tianjin Key Laboratory of Indoor Air Environmental Quality Control, School of Environmental Science and Engineering, Tianjin University, Tianjin 300350, China
- State Key Laboratory of Engines, Tianjin University, Tianjin 300072, China
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3
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Kim SI, Choi YJ, Lee MS, Lee DH. Nitration-Promoted Vanadate Catalysts for Low-Temperature Selective Catalytic Reduction of NO X with NH 3. ACS OMEGA 2023; 8:34152-34159. [PMID: 37744798 PMCID: PMC10515594 DOI: 10.1021/acsomega.3c05423] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Accepted: 08/29/2023] [Indexed: 09/26/2023]
Abstract
Vanadium-based catalysts have been commercially used in selective catalytic reduction (SCR), owing to their high catalytic activity and effectiveness across a wide temperature range; however, their catalytic efficiency decreases at lower temperatures under exposure to SOX. This decrease is largely due to ammonium sulfate generation on the catalyst surface. To overcome this limitation, we added ammonium nitrate to the V2O5-WO3/TiO2 catalyst, producing a V2O5-WO3/TiO2 catalyst with nitrate functional groups. With this approach, we found that it was possible to adjust the amount of these functional groups by varying the amount of ammonium nitrate. Overall, the resultant nitrate V2O5-WO3/TiO2 catalyst has large quantities of NO3- and chemisorbed oxygen, which improves the density of Brønsted and Lewis acid sites on the catalyst surface. Furthermore, the nitrated V2O5-WO3/TiO2 catalyst has a high NOX removal efficiency and N2 selectivity at low temperatures (i.e., 300 °C); this is because NO3- and chemisorbed oxygen, generated by nitrate treatment, facilitated the occurrence of a fast SCR reaction. The approach outlined in this study can be applied to a wide range of SCR catalysts, allowing for the development of more, low-temperature SCR catalysts.
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Affiliation(s)
- Sun-I Kim
- Green
Materials and Processes R&D Group, Korea
Institute of Industrial Technology, Ulsan 44413, Republic of Korea
| | - Yeong Jun Choi
- Green
Materials and Processes R&D Group, Korea
Institute of Industrial Technology, Ulsan 44413, Republic of Korea
| | - Min Seong Lee
- Green
Materials and Processes R&D Group, Korea
Institute of Industrial Technology, Ulsan 44413, Republic of Korea
| | - Duck Hyun Lee
- Green
Materials and Processes R&D Group, Korea
Institute of Industrial Technology, Ulsan 44413, Republic of Korea
- School
of Advanced Materials & Electrical Engineering, Industrial Technology
Center for Environment-Friendly Materials, Andong National University, Andong 36729, Republic
of Korea
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4
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Wang B. Preparation and application of foamed ceramic panels in interior design. SCIENCE AND ENGINEERING OF COMPOSITE MATERIALS 2023; 30. [DOI: 10.1515/secm-2022-0217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/01/2023]
Abstract
Abstract
A new type of foam ceramics was prepared with fly ash (CFA). Before sintering, the CFA underwent alkali activation, resulting in an even layer of hydroxy sodalite crystals covering the CFA particles. The pre-treatment of the CFA-alkali-activated material caused it to exhibit a reaction in sintering. The foamed ceramics had the best qualities when sintered at 1,300°C; the leaching toxicity studies of a material used in interior design revealed that during sintering.
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Affiliation(s)
- Bin Wang
- School of Digital Creativity and Design, Henan Vocational and Technical College , Zhengzhou , Henan, 450046 , China
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5
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Wang B, Feng X, Xu Y, Shi JW. Role of Ce in promoting low-temperature performance and hydrothermal stability of Ce/Cu-SSZ-13 in the selective catalytic reduction of NOx with NH3. Sep Purif Technol 2023. [DOI: 10.1016/j.seppur.2023.123679] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/29/2023]
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6
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Khivantsev K, Jaegers NR, Aleksandrov HA, Song I, Pereira-Hernandez XI, Engelhard MH, Tian J, Chen L, Motta Meira D, Kovarik L, Vayssilov GN, Wang Y, Szanyi J. Single Ru(II) Ions on Ceria as a Highly Active Catalyst for Abatement of NO. J Am Chem Soc 2023; 145:5029-5040. [PMID: 36812067 DOI: 10.1021/jacs.2c09873] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
Abstract
Atom trapping leads to catalysts with atomically dispersed Ru1O5 sites on (100) facets of ceria, as identified by spectroscopy and DFT calculations. This is a new class of ceria-based materials with Ru properties drastically different from the known M/ceria materials. They show excellent activity in catalytic NO oxidation, a critical step that requires use of large loadings of expensive noble metals in diesel aftertreatment systems. Ru1/CeO2 is stable during continuous cycling, ramping, and cooling as well as the presence of moisture. Furthermore, Ru1/CeO2 shows very high NOx storage properties due to formation of stable Ru-NO complexes as well as a high spill-over rate of NOx onto CeO2. Only ∼0.05 wt % of Ru is required for excellent NOx storage. Ru1O5 sites exhibit much higher stability during calcination in air/steam up to 750 °C in contrast to RuO2 nanoparticles. We clarify the location of Ru(II) ions on the ceria surface and experimentally identify the mechanism of NO storage and oxidation using DFT calculations and in situ DRIFTS/mass spectroscopy. Moreover, we show excellent reactivity of Ru1/CeO2 for NO reduction by CO at low temperatures: only 0.1-0.5 wt % of Ru is sufficient to achieve high activity. Modulation-excitation in situ infrared and XPS measurements reveal the individual elementary steps of NO reduction by CO on an atomically dispersed Ru ceria catalyst, highlighting unique properties of Ru1/CeO2 and its propensity to form oxygen vacancies/Ce+3 sites that are critical for NO reduction, even at low Ru loadings. Our study highlights the applicability of novel ceria-based single-atom catalysts to NO and CO abatement.
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Affiliation(s)
- Konstantin Khivantsev
- Institute for Integrated Catalysis, Pacific Northwest National Laboratory, Richland, Washington 99352 United States
| | - Nicholas R Jaegers
- Institute for Integrated Catalysis, Pacific Northwest National Laboratory, Richland, Washington 99352 United States
| | - Hristiyan A Aleksandrov
- Faculty of Chemistry and Pharmacy, Sofia University "St. Kliment Ohridski", 1, J. Bourchier boulevard, 1126 Sofia, Bulgaria
| | - Inhak Song
- Institute for Integrated Catalysis, Pacific Northwest National Laboratory, Richland, Washington 99352 United States
| | | | - Mark H Engelhard
- Institute for Integrated Catalysis, Pacific Northwest National Laboratory, Richland, Washington 99352 United States
| | - Jinshu Tian
- Institute for Integrated Catalysis, Pacific Northwest National Laboratory, Richland, Washington 99352 United States
| | - Linxiao Chen
- Institute for Integrated Catalysis, Pacific Northwest National Laboratory, Richland, Washington 99352 United States
| | - Debora Motta Meira
- Canadian Light Source: Canadian Light Source Inc., 44 Innovation Boulevard, Saskatoon, Saskatchewan S7N 2V3, Canada
| | - Libor Kovarik
- Institute for Integrated Catalysis, Pacific Northwest National Laboratory, Richland, Washington 99352 United States
| | - Georgi N Vayssilov
- Faculty of Chemistry and Pharmacy, Sofia University "St. Kliment Ohridski", 1, J. Bourchier boulevard, 1126 Sofia, Bulgaria
| | - Yong Wang
- Institute for Integrated Catalysis, Pacific Northwest National Laboratory, Richland, Washington 99352 United States
| | - János Szanyi
- Institute for Integrated Catalysis, Pacific Northwest National Laboratory, Richland, Washington 99352 United States
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7
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Yang Y, Gong Y, Wang Y, Wu X, Zhou Z, Weng W, Zhang Y. Advances in air pollution control for vessels in China. J Environ Sci (China) 2023; 123:212-221. [PMID: 36521985 DOI: 10.1016/j.jes.2022.03.026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Revised: 03/17/2022] [Accepted: 03/17/2022] [Indexed: 06/17/2023]
Abstract
Vessel emissions have contributed a great deal to air quality deterioration in China. Hence, the Chinese government has promulgated a series of stringent emission regulations. It is in this context that vessel emission control technology research is in full swing. In particular, during the 13th Five-Year Plan, the air pollution control technology of vessels has greatly improved. Vessel emission control has followed two main governance routes: source emission reduction and aftertreatment technology. Source control focuses on alternative fuels, with two main directions, the development of new fuels and the modification of existing fuels. Moreover, after-treatment technologies have also been developed, including wet desulfurization technology using seawater or alkaline liquids as wet washing liquids and selective catalytic reduction (SCR) for the control of NOx emission. Due to China's increasingly stringent emissions standards and regulations, work on the development of clean alternative fuels and further upgrading the collaborative application of after-treatment technologies to meet the near-zero-emissions requirements of vessels is still necessary.
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Affiliation(s)
- Yanping Yang
- State Key Laboratory of Clean Energy Utilization, College of Energy Engineering, Zhejiang University, Hangzhou 310027, China
| | - Yue Gong
- State Key Laboratory of Clean Energy Utilization, College of Energy Engineering, Zhejiang University, Hangzhou 310027, China
| | - Ying Wang
- State Key Laboratory of Clean Energy Utilization, College of Energy Engineering, Zhejiang University, Hangzhou 310027, China
| | - Xuecheng Wu
- State Key Laboratory of Clean Energy Utilization, College of Energy Engineering, Zhejiang University, Hangzhou 310027, China
| | - Zhiying Zhou
- Energy Engineering Design and Research Institute Co. Ltd., Zhejiang University, Hangzhou 310027, China
| | - Weiguo Weng
- Energy Engineering Design and Research Institute Co. Ltd., Zhejiang University, Hangzhou 310027, China
| | - Yongxin Zhang
- State Key Laboratory of Clean Energy Utilization, College of Energy Engineering, Zhejiang University, Hangzhou 310027, China.
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8
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Review of Improving the NOx Conversion Efficiency in Various Diesel Engines fitted with SCR System Technology. Catalysts 2022. [DOI: 10.3390/catal13010067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The diesel engine is utilized in most commercial vehicles to carry items from various firms; nevertheless, diesel engines emit massive amounts of nitrogen oxides (NOx) which are harmful to human health. A typical approach for reducing NOx emissions from diesel engines is the selective catalytic reduction (SCR) system; however, several reasons make reducing NOx emissions a challenge: urea particles frequently become solid in the injector and difficult to disseminate across the system; the injector frequently struggles to spray the smaller particles of urea; the larger urea particles from the injector readily cling to the system; it is also difficult to evaporate urea droplets because of the exhaust and wall temperatures (Tw), resulting in an increase in solid deposits in the system, uncontrolled ammonia water solution injection, and NOx emissions problems. The light-duty diesel engine (LDD), medium-duty diesel engine (MDD), heavy-duty diesel engine (HDD), and marine diesel engine use different treatments to optimize NOx conversion efficiency in the SCR system. This review analyzes several studies in the literature which aim to increase NOx conversion in different diesel engine types. The approach and methods demonstrated in this study provide a suitable starting point for future research into reducing NOx emissions from diesel engines, particularly for engines with comparable specifications.
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9
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Abdul Nasir J, Guan J, Keal TW, Desmoutier AW, Lu Y, Beale AM, Catlow CRA, Sokol AA. Influence of Solvent on Selective Catalytic Reduction of Nitrogen Oxides with Ammonia over Cu-CHA Zeolite. J Am Chem Soc 2022; 145:247-259. [PMID: 36548055 PMCID: PMC9837844 DOI: 10.1021/jacs.2c09823] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The copper-exchanged zeolite Cu-CHA has received considerable attention in recent years, owing to its application in the selective catalytic reduction (SCR) of NOx species. Here, we study the NH3-SCR reaction mechanism on Cu-CHA using the hybrid quantum mechanical/molecular mechanical (QM/MM) technique and investigate the effects of solvent on the reactivity of active Cu species. To this end, a comparison is made between water- and ammonia-solvated and bare Cu species. The results show the promoting effect of solvent on the oxidation component of the NH3-SCR cycle since the formation of important nitrate species is found to be energetically more favorable on the solvated Cu sites than in the absence of solvent molecules. Conversely, both solvent molecules are predicted to inhibit the reduction component of the NH3-SCR cycle. Diffuse reflectance infrared fourier-transform spectroscopy (DRIFTS) experiments exploiting (concentration) modulation excitation spectroscopy (MES) and phase-sensitive detection (PSD) identified spectroscopic signatures of Cu-nitrate and Cu-nitrosamine (H2NNO), important species which had not been previously observed experimentally. This is further supported by the QM/MM-calculated harmonic vibrational analysis. Additional insights are provided into the reactivity of solvated active sites and the formation of key intermediates including their formation energies and vibrational spectroscopic signatures, allowing the development of a detailed understanding of the reaction mechanism. We demonstrate the role of solvated active sites and their influence on the energetics of important species that must be explicitly considered for an accurate understanding of NH3-SCR kinetics.
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Affiliation(s)
- Jamal Abdul Nasir
- Department
of Chemistry, Kathleen Lonsdale Materials Chemistry, University College London, 20 Gordon Street, LondonWC1H 0AJ, U.K.,
| | - Jingcheng Guan
- Department
of Chemistry, Kathleen Lonsdale Materials Chemistry, University College London, 20 Gordon Street, LondonWC1H 0AJ, U.K.
| | - Thomas W. Keal
- Scientific
Computing Department, STFC Daresbury Laboratory, Keckwick Lane, Daresbury, WarringtonWA4 4AD, U.K.
| | - Alec W. Desmoutier
- Department
of Chemistry, Kathleen Lonsdale Materials Chemistry, University College London, 20 Gordon Street, LondonWC1H 0AJ, U.K.
| | - You Lu
- Scientific
Computing Department, STFC Daresbury Laboratory, Keckwick Lane, Daresbury, WarringtonWA4 4AD, U.K.
| | - Andrew M. Beale
- Department
of Chemistry, Christopher Ingold Building, University College London, 20 Gordon Street, LondonWC1H 0AJ, U.K.,UK
Catalysis Hub, Research Complex at Harwell, Rutherford Appleton Laboratory, R92 Harwell, OxfordshireOX11 0FA, U.K.
| | - C. Richard A. Catlow
- Department
of Chemistry, Kathleen Lonsdale Materials Chemistry, University College London, 20 Gordon Street, LondonWC1H 0AJ, U.K.,UK
Catalysis Hub, Research Complex at Harwell, Rutherford Appleton Laboratory, R92 Harwell, OxfordshireOX11 0FA, U.K.,School
of Chemistry, Cardiff University, Park Place, CardiffCF10 3AT, U.K.,
| | - Alexey A. Sokol
- Department
of Chemistry, Kathleen Lonsdale Materials Chemistry, University College London, 20 Gordon Street, LondonWC1H 0AJ, U.K.,
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10
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Cao Z, Cai X, Feltrin AC, Feng P, Kaiser A, Akhtar F. Calcium/strontium chloride impregnated zeolite A and X granules as optimized ammonia sorbents. RSC Adv 2022; 12:34910-34917. [PMID: 36540240 PMCID: PMC9727750 DOI: 10.1039/d2ra02981b] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Accepted: 11/19/2022] [Indexed: 08/15/2023] Open
Abstract
Calcium chloride (CaCl2) impregnated zeolite A and strontium chloride (SrCl2) impregnated zeolite A and X composite granules were evaluated as ammonia sorbents for automotive selective catalytic reduction systems. The SrCl2-impregnated zeolite A granules showed a 14% increase in ammonia uptake capacity (8.39 mmol g-1) compared to zeolite A granules (7.38 mmol g-1). Furthermore, composite granules showed 243% faster kinetics of ammonia sorption (0.24 mmol g-1 min-1) compared to SrCl2 (0.07 mmol g-1 min-1) in the first 20 min. The composite CaCl2/SrCl2 impregnated zeolite A granules combined the advantages of the zeolites and CaCl2/SrCl2, where the rapid physisorption from zeolites can reduce the ammonia loading and release time, and chemisorption from the CaCl2/SrCl2 offers abundant ammonia capacity. Moreover, by optimizing the content of SrCl2 loading, the composite granules maintained the granular form with a crushing load of 17 N per granule after ammonia sorption-desorption cycles. Such structurally stable composite sorbents offer an opportunity for fast ammonia loading/release in automotive selective catalytic reduction systems.
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Affiliation(s)
- Zhejian Cao
- Division of Materials Science, Luleå University of Technology 971 87 Luleå Sweden
| | - Xiaoping Cai
- School of Materials Science and Physics, China University of Mining and Technology 221116 Xuzhou People's Republic of China
| | - Ana Carolina Feltrin
- Division of Materials Science, Luleå University of Technology 971 87 Luleå Sweden
| | - Peizhong Feng
- School of Materials Science and Physics, China University of Mining and Technology 221116 Xuzhou People's Republic of China
| | - Andreas Kaiser
- Department of Energy Conversion, Technical University of Denmark 2800 Kgs. Lyngby Denmark
| | - Farid Akhtar
- Division of Materials Science, Luleå University of Technology 971 87 Luleå Sweden
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11
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Geng X, Xie C, Zhu B, Chen J, Sun Y, Xu M. Calcium poisoning mechanism on the selective catalytic reduction of NO x by ammonia over the γ-Fe 2O 3 (001) surface. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:88256-88268. [PMID: 35831648 DOI: 10.1007/s11356-022-21912-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Accepted: 07/04/2022] [Indexed: 06/15/2023]
Abstract
γ-Fe2O3 has an excellent low-temperature selective catalytic reduction (SCR) deNOx performance, but its resistance to alkaline earth metal calcium (Ca) is poor. In particular, the detailed mechanism of Ca poisoning on the γ-Fe2O3 catalyst at the atomic level is not clear. Hence, the density functional theory method was used in this research to investigate the influence mechanism of Ca poisoning on the NH3-SCR over the γ-Fe2O3 catalyst surface. The findings reveal that NH3, NO, and O2 molecules can bind to the γ-Fe2O3 (001) surface to generate coordinated ammonia, monodentate nitroso, and adsorption oxygen species, respectively. The main active site is Fe1-top. For the γ-Fe2O3 with Ca poisoning, the Ca atom has a high adsorption energy on the surface of γ-Fe2O3 (001), which covers the catalyst surface and reduces the active sites. The presence of Ca atom decreases the adsorption performance of NH3, while slightly improving the NO and O2 adsorption. In particular, the Ca atom restrains the NH3 activation and NH2 formation, which is detrimental to the NH3-SCR process.
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Affiliation(s)
- Xuan Geng
- School of Petroleum and Natural Gas Engineering, Changzhou University, Changzhou, Jiangsu, 213164, People's Republic of China
| | - Chaoyue Xie
- School of Petroleum and Natural Gas Engineering, Changzhou University, Changzhou, Jiangsu, 213164, People's Republic of China
| | - Baozhong Zhu
- School of Petroleum and Natural Gas Engineering, Changzhou University, Changzhou, Jiangsu, 213164, People's Republic of China
| | - Jiuyu Chen
- School of Petroleum and Natural Gas Engineering, Changzhou University, Changzhou, Jiangsu, 213164, People's Republic of China
| | - Yunlan Sun
- School of Petroleum and Natural Gas Engineering, Changzhou University, Changzhou, Jiangsu, 213164, People's Republic of China.
| | - Minggao Xu
- Center for Advanced Combustion and Energy, University of Science and Technology of China, Hefei, Anhui, 230026, People's Republic of China
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12
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Kazachenko AS, Issaoui N, Sagaama A, Malyar YN, Al-Dossary O, Bousiakou LG, Kazachenko AS, Miroshnokova AV, Xiang Z. Hydrogen bonds interactions in biuret-water clusters: FTIR, X-ray diffraction, AIM, DFT, RDG, ELF, NLO analysis. JOURNAL OF KING SAUD UNIVERSITY - SCIENCE 2022. [DOI: 10.1016/j.jksus.2022.102350] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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13
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Nasello ND, Gramigni F, Nova I, Tronconi E, Hofmann F, Dieterich S, Crocoll M, Weibel M. Transient Redox Behavior of a NH3-SCR Cu-CHA SCR Catalyst: Effect of O2 Feed Content Variation. Top Catal 2022. [DOI: 10.1007/s11244-022-01715-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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14
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Tatarchuk SW, Medvedev JJ, Li F, Tobolovskaya Y, Klinkova A. Nickel‐Catalyzed Urea Electrolysis: From Nitrite and Cyanate as Major Products to Nitrogen Evolution. Angew Chem Int Ed Engl 2022; 61:e202209839. [DOI: 10.1002/anie.202209839] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Indexed: 11/06/2022]
Affiliation(s)
- Stephen W. Tatarchuk
- Department of Chemistry and the Waterloo Institute for Nanotechnology University of Waterloo Ontario N2L 3G1 Canada
| | - Jury J. Medvedev
- Department of Chemistry and the Waterloo Institute for Nanotechnology University of Waterloo Ontario N2L 3G1 Canada
| | - Feng Li
- Department of Chemistry and the Waterloo Institute for Nanotechnology University of Waterloo Ontario N2L 3G1 Canada
| | - Yulia Tobolovskaya
- Department of Chemistry and the Waterloo Institute for Nanotechnology University of Waterloo Ontario N2L 3G1 Canada
| | - Anna Klinkova
- Department of Chemistry and the Waterloo Institute for Nanotechnology University of Waterloo Ontario N2L 3G1 Canada
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15
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Mohammadi A, Praty C, Farzi A, Soleimanzadeh H, Schwarz S, Stöger-Pollach M, Bernardi J, Penner S, Niaei A. Influence of CeO2 and WO3 Addition to Impregnated V2O5/TiO2 Catalysts on the Selective Catalytic Reduction of NOx with NH3. Catal Letters 2022. [DOI: 10.1007/s10562-022-04108-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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16
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Yashnik SA. Catalytic Diesel Exhaust Systems: Modern Problems and Technological Solutions for Modernization of the Oxidation Catalyst. CATALYSIS IN INDUSTRY 2022. [DOI: 10.1134/s2070050422030060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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17
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Tatarchuk SW, Medvedev JJ, Li F, Tobolovskaya Y, Klinkova A. Nickel‐Catalyzed Urea Electrolysis: From Nitrite and Cyanate as Major Products to Nitrogen Evolution. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202209839] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | | | - Feng Li
- University of Waterloo Chemistry CANADA
| | | | - Anna Klinkova
- University of Waterloo Chemistry 200 University Ave W N2L 3G1 Waterloo CANADA
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18
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Synthesis of Vanadium-Containing Catalytically Active Phases for Exhaust Gas Neutralizers of Motor Vehicles and Industrial Enterprises. Catalysts 2022. [DOI: 10.3390/catal12080842] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The catalytically active vanadium-containing system of γ-Al2O3 was studied using a wide range of physical and chemical methods, depending on the synthesis conditions. It is shown that the vanadium-containing system includes several complexes with different thermal stabilities and catalytic activities. Low-active complexes are destroyed with the formation of more active ones based on V2O5 oxide, as the temperature of heat treatment increases. It can be assumed that V2O5 oxide has the decisive role in its catalytic activity. It was concluded that the vanadium-containing catalytic system on aluminium oxide, in the studied temperature range, is thermally stable and shows high activity not only in the reduction of nitrogen oxides but also in the oxidation of hydrocarbons (even of the most difficult ones, such as oxidizable methane). These properties of the system make it quite promising in the field of application for the purification of the exhaust gases of motor transport and industrial enterprises with environmentally harmful components, as well as for understanding the mechanism of the action of the catalysts in these processes, which is very important for solving the problems of decarbonization and achieving carbon neutrality.
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Progress in Metal-Organic Framework Catalysts for Selective Catalytic Reduction of NOx: A Mini-Review. ATMOSPHERE 2022. [DOI: 10.3390/atmos13050793] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Nitrogen oxides released from the combustion of fossil fuels are one of the main air pollutants. Selective catalytic reduction technology is the most widely used nitrogen oxide removal technology in the industry. With the development of nanomaterials science, more and more novel nanomaterials are being used as catalysts for the selective reduction of nitrogen oxides. In recent years, metal-organic frameworks (MOFs), with large specific surface areas and abundant acid and metal sites, have been extensively studied in the selective catalytic reduction of nitrogen oxides. This review summarizes recent progress in monometallic MOFs, bimetallic MOFs, and MOF-derived catalysts for the selective catalytic reduction of nitrogen oxides and compares the reaction mechanisms of different catalysts. This article also suggests the advantages and disadvantages of MOF-based catalysts compared with traditional catalysts and points out promising research directions in this field.
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Study on the mechanism of NOx reduction by NH3-SCR over Mn and M(M=V,Ti) co-doped CoCr2O4 catalyst. MOLECULAR CATALYSIS 2022. [DOI: 10.1016/j.mcat.2022.112283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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21
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Kalyankar A, Backhaus J, Munnannur A, Liu ZG. Numerical and Experimental Investigation of Ammonia Uniformity in a Compact Selective Catalytic Reduction System. Ind Eng Chem Res 2022. [DOI: 10.1021/acs.iecr.2c00399] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Apoorv Kalyankar
- Cummins Emission Solutions Inc. 1801 U.S. Highway 51-138, Stoughton, Wisconsin 53589, United States
| | - Jacob Backhaus
- Cummins Emission Solutions Inc. 1801 U.S. Highway 51-138, Stoughton, Wisconsin 53589, United States
| | - Achuth Munnannur
- Cummins Emission Solutions Inc. 1801 U.S. Highway 51-138, Stoughton, Wisconsin 53589, United States
| | - Z. Gerald Liu
- Cummins Emission Solutions Inc. 1801 U.S. Highway 51-138, Stoughton, Wisconsin 53589, United States
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22
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Flow Analysis of PM/NOX Aftertreatment System for Emergency Generator. APPLIED SCIENCES-BASEL 2022. [DOI: 10.3390/app12094404] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Emergency generators normally use diesel engines. The generators need to conduct weekly no-load operation inspections to ensure stable performance in emergency situations. In particular, the generators with large diesel engines mainly use rectangle-type filter substrates. To minimize hazardous emissions generated by generators, optimizing the reduction efficiency through computational fluid dynamics (CFD) analysis of flow characteristics of particulate matter (PM)/NOX reduction system is important. In this study, we analyzed internal flow by CFD, which is difficult to confirm by experimental method. The main factors in our numerical study are the changes of flow uniformity and back pressure. As a result, the flow distribution characteristics according to the cross-sectional shape are similar at high engine loads. Spraying urea in the reverse direction increases static pressure, greatly improving flow uniformity. Raising the selective catalyst reduction (SCR) diffuser angle to 30 degrees improves both back pressure and flow uniformity characteristics, and when the porosity increases, both flow uniformity and back pressure decrease.
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Spatially Resolved Measurements of HNCO Hydrolysis over SCR Catalysts. CHEM-ING-TECH 2022. [DOI: 10.1002/cite.202100192] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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24
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Lou D, Qi B, Zhang Y, Fang L. Study on the Emission Characteristics of Urban Buses at Different Emission Standards Fueled with Biodiesel Blends. ACS OMEGA 2022; 7:7213-7222. [PMID: 35252711 PMCID: PMC8892655 DOI: 10.1021/acsomega.1c06992] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Accepted: 02/02/2022] [Indexed: 06/14/2023]
Abstract
Biodiesel is a promising clean and alternative fuel that can meet the demand of energy saving and environmental protection. In this study, the effects of biodiesel blends on the gaseous and particulate emission characteristics of China-III, IV, and V urban buses were investigated based on a heavy chassis dynamometer. The results showed that the biodiesel blend resulted in a reduction in CO, THC, PN, and PM emission but an increase in the NOx and CO2 emission, and the effects were enhanced with the biodiesel ratio, which also depended on the bus speed. Simultaneously, the emission standards of buses had an obvious effect on the emissions and changed the effect of biodiesel on the emissions. A higher emission standard of the bus highlighted the effect of biodiesel on the emission. From China-III to China-IV to China-V buses, the comprehensive changes produced by B5 in the emissions increased from 5.57 to 6.78 to 6.83%, while for B10, a significant increase in the changes was obtained, reaching 12.98, 14.68, and 15.02%, respectively, for the three emission stage buses.
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Nagata T, Wu JWJ, Nakano M, Ohshimo K, Misaizu F. Geometrical Structures of Gas-Phase Cerium Oxide Cluster Cations after Reaction with Nitric Oxide Studied by Ion Mobility Mass Spectrometry. J Phys Chem A 2022; 126:1204-1210. [PMID: 35167295 DOI: 10.1021/acs.jpca.1c10835] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Cerium oxide cluster cations were reacted with nitric oxide molecules and then measured by ion mobility mass spectrometry (IMMS). CenO2n+1N+ species appeared as products of the reaction CenO2n+ + NO → CenO2n+1N+, and their collision cross sections (CCSs) with helium were obtained by IMMS. The experimental CCSs of CenO2n+1N+ were 2-6 Å2 larger than those of CenO2n+ for n = 4-10. Geometrical structures of Ce4O9N+ and Ce5O11N+ were assigned by comparing experimental CCSs with theoretically calculated CCSs of candidate structures. The suggested structures showed that the adsorbed NO molecule is oxidized by the CenO2n+ cluster into a nitrite (NO2-) or nitrate (NO3-). The CenO2n+1N+ species are regarded as intermediates of the NO oxidation reaction CenO2n+ + NO → CenO2n-1+ + NO2, and therefore, the present results are helpful for understanding redox reactions involving gas-phase CenO2n+ cluster ions.
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Affiliation(s)
- Toshiaki Nagata
- Department of Chemistry, Graduate School of Science, Tohoku University, 6-3 Aoba, Aramaki, Aoba-ku, Sendai 980-8578, Japan
| | - Jenna W J Wu
- Department of Chemistry, Graduate School of Science, Tohoku University, 6-3 Aoba, Aramaki, Aoba-ku, Sendai 980-8578, Japan
| | - Motoyoshi Nakano
- Department of Chemistry, Graduate School of Science, Tohoku University, 6-3 Aoba, Aramaki, Aoba-ku, Sendai 980-8578, Japan
| | - Keijiro Ohshimo
- Department of Chemistry, Graduate School of Science, Tohoku University, 6-3 Aoba, Aramaki, Aoba-ku, Sendai 980-8578, Japan
| | - Fuminori Misaizu
- Department of Chemistry, Graduate School of Science, Tohoku University, 6-3 Aoba, Aramaki, Aoba-ku, Sendai 980-8578, Japan
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Bishop GA, Haugen MJ, McDonald BC, Boies AM. Utah Wintertime Measurements of Heavy-Duty Vehicle Nitrogen Oxide Emission Factors. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:1885-1893. [PMID: 35044770 DOI: 10.1021/acs.est.1c06428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
There have only been a few wintertime studies of heavy-duty vehicle (HDV) NOx emissions in the United States, and while they have observed increased emissions, fleet characterization to identify the cause has been lacking. We have collected wintertime measurements of NOx emission factors from 1591 HDVs at a Utah Port of Entry in December 2020 that includes individual vehicle identification. In general, NOx emission factors for 2011 and newer chassis model year HDV are significantly higher than those for 2017 spring measurements from California. The newest chassis model year HDV (2017-2021) NOx emission factors are similar, indicating no significant emission deterioration over the 5 year period, though they are still approximately a factor of 3 higher than the portable emission measurement on-road enforcement standard. We estimate that ambient temperature increases NOx emissions no more than 25% in the newer HDV, likely through reductions in catalyst efficiencies. NOx emissions increase to a significantly higher level for the 2011-2013 chassis model year vehicles, where within the uncertainties, they have emissions similar to older precontrol vehicles, indicating that they have lost their NOx control capabilities within 8 years. MOVES3 modeling of the Utah fleet underpredicted mean NOx emissions by a factor of 1.8 but the MOVES3 estimate is helped by including a larger fraction of high-emitting glider kit trucks (new chassis with pre-emission control engines) than found in the observations.
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Affiliation(s)
- Gary A Bishop
- Department of Chemistry and Biochemistry, University of Denver, Denver, Colorado 80208, United States
| | - Molly J Haugen
- Department of Engineering, University of Cambridge, Cambridge CB2 1PZ, United Kingdom
| | - Brian C McDonald
- Chemical Sciences Laboratory, National Oceanic and Atmospheric Administration, Boulder, Colorado 80305, United States
| | - Adam M Boies
- Department of Engineering, University of Cambridge, Cambridge CB2 1PZ, United Kingdom
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Abstract
Ammonia combustion is a promising energy source as a carbon free fuel without greenhouse gas emissions. However, since the auto-ignition temperature is 651 degrees Celsius and the range of flammability limit is not wide compared to other fuels, fundamental studies on ammonia fires have rarely been conducted so far. Therefore, this study aims to numerically estimate fire spread characteristics when ammonia fuel in a high-pressure state leaks to the outside, especially focusing on the flammability limit according to oxygen concentration. Three kinds of reaction mechanism for numerical analysis were adopted to compare the flame structure, flammability limit, and combustion characteristics. Plank-mean absorption coefficients of nitrogen species were taken for the radiation model, in addition to the optically thin model. The effect of radiation heat loss could be identified from the maximum flame temperature trend at a low strain rate. It was confirmed that the pyrolysis of ammonia in the preheated zone results in hydrogen production, and the generated hydrogen contributes to heat release rate in the flame zone. It is found that the contribution of hydrogen would be an important role in the flammability limit of ammonia combustion. Finally, Karlovitz and Peclet numbers showed well the extinction behaviors of ammonia combustion as a result of LOC (Limit Oxygen Concentration) analysis as a function of global strain rate.
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28
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Vennewald M, Iemhoff A, Ditz D, Palkovits R. Carbonaceous materials are not suitable catalysts for direct NO decomposition in exhaust aftertreatment. Catal Sci Technol 2022. [DOI: 10.1039/d1cy02282b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
New approaches for direct NO decomposition catalysis are urgently needed, but using carbonaceous supports appears not to be the way to go.
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Affiliation(s)
- Maurice Vennewald
- Chair of Heterogeneous Catalysis and Chemical Technology, ITMC, RWTH Aachen University, Worringerweg 2, DE-52074 Aachen, Germany
| | - Andree Iemhoff
- Chair of Heterogeneous Catalysis and Chemical Technology, ITMC, RWTH Aachen University, Worringerweg 2, DE-52074 Aachen, Germany
| | - Daniel Ditz
- Chair of Heterogeneous Catalysis and Chemical Technology, ITMC, RWTH Aachen University, Worringerweg 2, DE-52074 Aachen, Germany
| | - Regina Palkovits
- Chair of Heterogeneous Catalysis and Chemical Technology, ITMC, RWTH Aachen University, Worringerweg 2, DE-52074 Aachen, Germany
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29
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Yue G, Qiu T, Lei Y. Experimental demonstration of NO x reduction and ammonia slip for diesel engine SCR system. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:1118-1133. [PMID: 34350573 DOI: 10.1007/s11356-021-15592-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Accepted: 07/19/2021] [Indexed: 06/13/2023]
Abstract
This paper investigates the characteristics of selective catalytic reduction (SCR) with a V2O5-WO3/TiO2 catalyst by studying the key parameters and determining a method for controlling ammonia injection with a sample test bench. Four parameters are defined and adopted to represent the characteristics of nitrogen oxides (NOx) and the ammonia reaction. The effects of NH3/NOx ratio (NSR), catalyst temperature, and ammonia injection period on NOx conversion efficiency and ammonia slip are investigated. The correlation between ammonia slip and ammonia saturation storage level is studied. The experimental results show that the ammonia saturation storage level has a great impact on NOx reduction and ammonia slip. The NOx conversion efficiency and ammonia slip strongly depend on the ammonia saturation storage level. Under such conditions, the NOx conversion efficiency is best when the ammonia saturation storage level is 68.2~73%, and the value reaches 75% before ammonia slip. Pulse injection improves the NOx conversion efficiency and limits ammonia slip. Comprehensive comparison shows that the injected ratio of NH3/NOx is first larger and then smaller than is beneficial for the rapid improvement of NOx conversion efficiency; the appropriate NH3/NOx ratio and continuous injection time must be controlled, or it is easy to cause ammonia slip. Therefore, a control algorithm based on ammonia storage saturation level has been proposed. According to the difference between the actual value of ammonia storage saturation and the target value, the controller corrects the injection of urea to achieve control of ammonia storage saturation level. The period of pulse injection has little influence on the mean value of NOx at the outlet; however, it affects the peak level of NOx and ammonia slip. Using varied period pulse injection further improves the NOx conversion efficiency and restrains ammonia slip. The outlet level of NOx can be reduced by adopting a suitable ammonia pulse injection interval.
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Affiliation(s)
- Guangzhao Yue
- School of Transportation and Vehicle Engineering, Shandong University of Technology, Zibo, 255000, China.
| | - Tao Qiu
- College of Environment and Energy Engineering, Beijing University of Technology, Beijing, 100124, China
| | - Yan Lei
- College of Environment and Energy Engineering, Beijing University of Technology, Beijing, 100124, China
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30
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Hu M, Meng F, Li N, Zhang S, Ma J. Insight Into the CuOx Interacts with Oxygen Vacancies on the Surface of Black-TiO2 for NO Oxidation. Catal Letters 2021. [DOI: 10.1007/s10562-021-03729-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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31
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Yang Q, Wang X, Wang X, Li Q, Li L, Yang W, Chu X, Liu H, Men J, Peng Y, Ma Y, Li J. Surface Reconstruction of a Mullite-Type Catalyst via Selective Dissolution for NO Oxidation. ACS Catal 2021. [DOI: 10.1021/acscatal.1c03955] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Qilei Yang
- School of Environment, Tsinghua University, Beijing 100084, P. R. China
| | - Xiao Wang
- Department of Chemical Engineering, McGill University, Montreal, Quebec H3A 0C5, Canada
| | - Xiyang Wang
- Waterloo Institute for Nanotechnology, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
| | - Qi Li
- School of Environment, Tsinghua University, Beijing 100084, P. R. China
| | - Lei Li
- School of Environment, Tsinghua University, Beijing 100084, P. R. China
| | - Weinan Yang
- School of Environment, Tsinghua University, Beijing 100084, P. R. China
| | - Xuefeng Chu
- School of Environment, Tsinghua University, Beijing 100084, P. R. China
| | - Hao Liu
- School of Environment, Tsinghua University, Beijing 100084, P. R. China
| | - Jishuai Men
- Air Pollution Control Laboratory, Shandong Daming Science and Technology Co., Ltd., Shandong 277500, P. R. China
| | - Yue Peng
- School of Environment, Tsinghua University, Beijing 100084, P. R. China
| | - Yongliang Ma
- School of Environment, Tsinghua University, Beijing 100084, P. R. China
| | - Junhua Li
- School of Environment, Tsinghua University, Beijing 100084, P. R. China
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Shang T, Fan C, Fu Z, Wei M, Wang T. Combination of Pilot Injection and a NH 3-SCR System To Reduce NOx Emissions of a Nonroad Compression Ignition Engine. ACS OMEGA 2021; 6:28871-28879. [PMID: 34746579 PMCID: PMC8567372 DOI: 10.1021/acsomega.1c03824] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Accepted: 09/16/2021] [Indexed: 06/13/2023]
Abstract
This study compared the NOx emissions of a nonroad compression ignition engine using pilot injection and a NH3-SCR system and revealed their effects on NOx reduction. Furthermore, the interaction of pilot injection and the NH3-SCR system on NOx reduction was also studied by simultaneously using the two technologies under broad engine operating conditions. The pilot-main interval and the rate of pilot-to-main injection used in this study are in the range of 2∼8 CA and 9.5∼58.5%, respectively. Results showed that alteration in the pilot-main injection interval and the pilot-injection fuel amount under low load conditions was prone to lead to more variation in NOx emissions in comparison with that under high-load conditions. Relative to the pilot-main injection interval, the pilot-injection fuel amount played a more important role in the NOx emission. Lower NOx emissions could be achieved when using a smaller pilot-injection amount. However, excessively advanced pilot injection and a larger pilot-injection amount would increase the NOx emissions. Under a lower engine load, the effect of pilot injection on NOx reduction enhanced, whereas the effect of the NH3-SCR system diminished. Over broad operating conditions, the NOx reduction percentage by pilot injection coupled with the SCR system was lower than the total reduction degree when separately using pilot injection and the SCR system.
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Affiliation(s)
- Tansu Shang
- State
Key Laboratory of Engines, Tianjin University, Tianjin 300072, PR China
- State
Key Laboratory of Power System of Tractor, Luoyang 471003, China
- Luoyang
Tractor Research Institute Co., Ltd, Luoyang 471003, China
| | - Chenyang Fan
- College
of Vehicle and Transportation Engineering, Henan University of Science and Technology, No.48 Xiyuan Road, Jianxi District, Luoyang 471003, China
| | - Zheng Fu
- Luoyang
Xiyuan Vehicle and Power Inspection Institute Co., Ltd, Luoyang 471003, China
| | - Mingliang Wei
- State
Key Laboratory of Power System of Tractor, Luoyang 471003, China
- Luoyang
Tractor Research Institute Co., Ltd, Luoyang 471003, China
| | - Tianyou Wang
- State
Key Laboratory of Engines, Tianjin University, Tianjin 300072, PR China
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Zhu N, Qian F, Xu X, Wang M, Teng Q. Thermogravimetric Experiment of Urea at Constant Temperatures. MATERIALS 2021; 14:ma14206190. [PMID: 34683779 PMCID: PMC8539392 DOI: 10.3390/ma14206190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Revised: 10/11/2021] [Accepted: 10/14/2021] [Indexed: 11/23/2022]
Abstract
There are still many unsolved mysteries in the thermal decomposition process of urea. This paper studied the thermal decomposition process of urea at constant temperatures by the thermal gravimetric–mass spectrometry analysis method. The results show that there are three obvious stages of mass loss during the thermal decomposition process of urea, which is closely related to the temperature. When the temperature was below 160 °C, urea decomposition almost did not occur, and molten urea evaporated slowly. When the temperature was between 180 and 200 °C, the content of biuret, one of the by-products in the thermal decomposition of urea, reached a maximum. When the temperature was higher than 200 °C, the first stage of mass loss was completed quickly, and urea and biuret rapidly broke down. When the temperature was about 240 °C, there were rarely urea and biuret in residual substance; however, the content of cyanuric acid was still rising. When the temperature was higher than 280°C, there was a second stage of mass loss. In the second stage of mass loss, when the temperature was higher than 330 °C, mass decreased rapidly, which was mainly due to the decomposition of cyanuric acid. When the temperature was higher than 380 °C, the third stage of mass loss occurred. However, when the temperature was higher than 400 °C, and after continuous heating was applied for a sufficiently long time, the residual mass was reduced to almost zero eventually.
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Affiliation(s)
- Neng Zhu
- School of Automotive and Transportation Engineering, Wuhan University of Science and Technology, Wuhan 430081, China; (N.Z.); (X.X.)
| | - Feng Qian
- School of Automotive and Transportation Engineering, Wuhan University of Science and Technology, Wuhan 430081, China; (N.Z.); (X.X.)
- Correspondence: ; Tel.: +86-180-6206-0988
| | - Xiaowei Xu
- School of Automotive and Transportation Engineering, Wuhan University of Science and Technology, Wuhan 430081, China; (N.Z.); (X.X.)
| | - Mingda Wang
- Chinese Academy of Environmental Sciences, Beijing 100012, China; (M.W.); (Q.T.)
| | - Qi Teng
- Chinese Academy of Environmental Sciences, Beijing 100012, China; (M.W.); (Q.T.)
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Ren M, Zhang H, Zhou H, Fan Y, Cao R, Gao Y, Chen J. Effect of urea on chlorinated aromatics formation mediated by copper and iron species in combustion flue gas. CHEMOSPHERE 2021; 280:130963. [PMID: 34162116 DOI: 10.1016/j.chemosphere.2021.130963] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 04/22/2021] [Accepted: 05/16/2021] [Indexed: 06/13/2023]
Abstract
Urea ((NH2)2CO) is widely applied to the reduction of NOX in modern full-scale solid waste incineration systems, but there is a lack of knowledge about how urea affects the formation and emission of Cl-aromatics. In this study, we investigated the formation of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and polychlorinated polychlorinated naphthalenes (PCNs) via electrophilic chlorination and precursor pathway mediated by model fly ashes containing Cu and Fe species with or without urea addition. The results indicated that the addition of urea promoted the direct chlorination of parent aromatics over Cu (Ⅱ) chlorides and the coupling reaction of chlorophenols over Fe species, while suppressed the catalytic chlorination of parent aromatics over Fe (Ⅲ) chlorides and the coupling reaction of chlorophenols over Cu species. The diverse effects should be mainly attributed to the formation of complex salts containing NH3 and NH4+. The formation of complex salts of Fe chlorides and NH4Cl could hinder the oxidization of Fe chlorides, and thus maintain the high activity of Fe species for catalyzing the coupling reaction of chlorophenols. The formation of complex salts of Cu (Ⅱ) chloride and NH3 could prevent the chemical sorption of phenoxyl groups, and thus suppress the coupling reaction of chlorophenols. NH3 released from the thermal decomposition of urea could not only react with Cl2 to suppress the catalytic chlorination of aromatics, but also neutralize HCl to accelerate the direct chlorination of aromatics. In general, urea should act as inhibitor for suppressing the formation of Cl-aromatics in solid waste incineration systems.
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Affiliation(s)
- Meihui Ren
- CAS Key Laboratory of Separation Sciences for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning, 116023, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Haijun Zhang
- CAS Key Laboratory of Separation Sciences for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning, 116023, China.
| | - Hongquan Zhou
- Shanghai Environmental Sanitation Engineering Design Institute Co., Ltd., Shanghai, 200232, China
| | - Yun Fan
- CAS Key Laboratory of Separation Sciences for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning, 116023, China
| | - Rong Cao
- CAS Key Laboratory of Separation Sciences for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning, 116023, China
| | - Yuan Gao
- CAS Key Laboratory of Separation Sciences for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning, 116023, China
| | - Jiping Chen
- CAS Key Laboratory of Separation Sciences for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning, 116023, China
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Experimental Study on Diesel Engine Emission Characteristics Based on Different Exhaust Pipe Coating Schemes. MICROMACHINES 2021; 12:mi12101155. [PMID: 34683206 PMCID: PMC8541148 DOI: 10.3390/mi12101155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Revised: 09/22/2021] [Accepted: 09/24/2021] [Indexed: 11/25/2022]
Abstract
The thermal insulation performance of exhaust pipes coated with various materials (basalt and glass fiber materials) under different braiding forms (sleeve, winding and felt types) and the effects on the emission characteristics of diesel engines were experimentally studied through engine bench tests. The results indicated that the thermal insulation performance of basalt fiber was higher than that of glass fiber, and more notably advantageous at the early stage of the diesel engine idle cold phase. The average temperature drop during the first 600 s of the basalt felt (BF) pipe was 2.6 °C smaller than that of the glass fiber felt (GF) pipe. Comparing the different braiding forms, the temperature decrease in the felt-type braided material was 2.6 °C and 2.9 °C smaller than that in the sleeve- and winding-type braided materials, respectively. The basalt material was better than the glass fiber material regarding the gaseous pollutant emission reduction performance, especially in the idling cold phase of diesel engines. The NOx conversion rate of the BF pipe was 7.4% higher than that of the GF pipe, and the hydrocarbon (HC) conversion rate was 2.3% higher than that of the GF pipe, while the CO conversion rate during the first 100 s was 24.5% higher than that of the GF pipe. However, the particulate matter emissions were not notably different.
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36
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Bendrich M, Opitz B, Scheuer A, Hayes RE, Votsmeier M. Selective catalytic reduction: Adding an ammonia slip catalyst mitigates dosing errors. CAN J CHEM ENG 2021. [DOI: 10.1002/cjce.24293] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Michelle Bendrich
- University of Alberta Edmonton Alberta Canada
- Umicore AG & Co. KG Hanau Germany
| | - Bastian Opitz
- Umicore AG & Co. KG Hanau Germany
- Technische Universität Darmstadt Darmstadt Germany
| | | | | | - Martin Votsmeier
- Umicore AG & Co. KG Hanau Germany
- Technische Universität Darmstadt Darmstadt Germany
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McCaffery C, Zhu H, Tang T, Li C, Karavalakis G, Cao S, Oshinuga A, Burnette A, Johnson KC, Durbin TD. Real-world NOx emissions from heavy-duty diesel, natural gas, and diesel hybrid electric vehicles of different vocations on California roadways. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 784:147224. [PMID: 33905931 DOI: 10.1016/j.scitotenv.2021.147224] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 04/11/2021] [Accepted: 04/14/2021] [Indexed: 05/28/2023]
Abstract
This study assessed the real-world nitrogen oxide (NOx) emissions from 50 heavy-duty vehicles of different vocations and engine technologies using portable emissions measurement systems (PEMS). This is one of the most comprehensive in-use emissions studies conducted to date, which played a key role in the development of CARB's (California Air Recourses Board) updated EMission FACtor (EMFAC) model, especially for natural gas vehicles. In-use emissions testing was performed on school and transit buses, refuse haulers, goods movement vehicles, and delivery vehicles while were driven over their normal operating routes in the South Coast Air Basin. Engine technologies included diesel engines with and without selective catalytic reduction (SCR) systems, compressed natural gas (CNG) engines and liquified petroleum gas (LPG) engines, and SCR-equipped diesel hybrid electric vehicles. For most vehicles, the in-use NOx emissions were higher than the certification standards for the engine. Diesel vehicles generally showed higher brake-specific NOx emissions compared to the CNG vehicles. NOx emissions were strongly dependent on the SCR temperature, with SCR temperatures below 200 °C resulting in elevate brake-specific NOx. The 0.02 g/bhp-hr certified CNG vehicles showed the largest reductions in NOx emissions. The diesel hybrid electric vehicles showed important distance-specific NOx benefits compared to the conventional diesel vehicles, but higher emissions compared to the CNG and LPG vehicles. Overall, average NOx reductions were 75%, 94%, 65%, 79%, respectively, for the 0.2 CNG, 0.02 CNG, diesel hybrid electric, and LPG vehicles compared to diesel vehicles, due in part to some diesel vehicles with particularly high emissions, indicating that the widespread implementation of advanced technology and alternative fuel vehicles could provide important NOx reductions and a path for meeting air quality targets in California and elsewhere.
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Affiliation(s)
- Cavan McCaffery
- University of California, Bourns College of Engineering, Center for Environmental Research and Technology (CE-CERT), 1084 Columbia Avenue, Riverside, CA 92507, USA
| | - Hanwei Zhu
- University of California, Bourns College of Engineering, Center for Environmental Research and Technology (CE-CERT), 1084 Columbia Avenue, Riverside, CA 92507, USA; Department of Chemical and Environmental Engineering, Bourns College of Engineering, University of California, Riverside, CA 92521, USA
| | - Tianbo Tang
- University of California, Bourns College of Engineering, Center for Environmental Research and Technology (CE-CERT), 1084 Columbia Avenue, Riverside, CA 92507, USA; Department of Chemical and Environmental Engineering, Bourns College of Engineering, University of California, Riverside, CA 92521, USA
| | - Chengguo Li
- University of California, Bourns College of Engineering, Center for Environmental Research and Technology (CE-CERT), 1084 Columbia Avenue, Riverside, CA 92507, USA
| | - Georgios Karavalakis
- University of California, Bourns College of Engineering, Center for Environmental Research and Technology (CE-CERT), 1084 Columbia Avenue, Riverside, CA 92507, USA; Department of Chemical and Environmental Engineering, Bourns College of Engineering, University of California, Riverside, CA 92521, USA.
| | - Sam Cao
- South Coast Air Quality Management District, 21865 Copley Dr, Diamond Bar, CA 91765, USA
| | - Adewale Oshinuga
- South Coast Air Quality Management District, 21865 Copley Dr, Diamond Bar, CA 91765, USA
| | | | - Kent C Johnson
- University of California, Bourns College of Engineering, Center for Environmental Research and Technology (CE-CERT), 1084 Columbia Avenue, Riverside, CA 92507, USA; Department of Chemical and Environmental Engineering, Bourns College of Engineering, University of California, Riverside, CA 92521, USA
| | - Thomas D Durbin
- University of California, Bourns College of Engineering, Center for Environmental Research and Technology (CE-CERT), 1084 Columbia Avenue, Riverside, CA 92507, USA; Department of Chemical and Environmental Engineering, Bourns College of Engineering, University of California, Riverside, CA 92521, USA.
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38
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Tan W, Wang C, Yu S, Li Y, Xie S, Gao F, Dong L, Liu F. Revealing the effect of paired redox-acid sites on metal oxide catalysts for efficient NO x removal by NH 3-SCR. JOURNAL OF HAZARDOUS MATERIALS 2021; 416:125826. [PMID: 34492788 DOI: 10.1016/j.jhazmat.2021.125826] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 03/27/2021] [Accepted: 04/03/2021] [Indexed: 06/13/2023]
Abstract
Understanding the nature of active sites on metal oxide catalysts in the selective catalytic reduction (SCR) of NO by NH3 (NH3-SCR) is a crucial prerequisite for the development of novel efficient NH3-SCR catalysts. In this work, two CeO2-based SCR catalyst systems with diverse acidic metal oxides-CeO2 interfaces, i.e., Nb2O5-CeO2 (Nb2O5/CeO2 and CeO2/Nb2O5) and WO3-CeO2 (WO3/CeO2 and CeO2/WO3), were prepared and used to reveal the relationship between NH3-SCR activity and surface acidity/redox properties. In combination with the results of the NH3-SCR activity test and various characterizations, it was found that the NH3-SCR performance of Nb2O5-CeO2 and WO3-CeO2 catalysts was highly dependent on the strong interactions between the redox component (CeO2) and acidic component (Nb2O5 or WO3), as well as the amount of paired redox-acid sites. From a quantitative perspective, an activity-surface acidity/redox property relationship was proposed. For both Nb2O5-CeO2 and WO3-CeO2 catalysts systems operated at the more concerned low-temperature range (200 °C), the NH3-SCR activity in low NOx conversion region (< 40%) was mainly dominated by the surface acidity of catalysts, while the NH3-SCR activity in high NOx conversion region (> 40%) was more determined by redox properties.
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Affiliation(s)
- Wei Tan
- Department of Civil, Environmental, and Construction Engineering, Catalysis Cluster for Renewable Energy and Chemical Transformations (REACT), NanoScience Technology Center (NSTC), University of Central Florida, Orlando, FL 32816, United States; Key Laboratory of Mesoscopic Chemistry of MOE, School of Chemistry and Chemical Engineering, Nanjing University, Jiangsu Key Laboratory of Vehicle Emissions Control, School of Environment, Center of Modern Analysis, Nanjing 210093, China
| | - Chunying Wang
- Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
| | - Shuohan Yu
- Key Laboratory of Mesoscopic Chemistry of MOE, School of Chemistry and Chemical Engineering, Nanjing University, Jiangsu Key Laboratory of Vehicle Emissions Control, School of Environment, Center of Modern Analysis, Nanjing 210093, China
| | - Yaobin Li
- Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
| | - Shaohua Xie
- Department of Civil, Environmental, and Construction Engineering, Catalysis Cluster for Renewable Energy and Chemical Transformations (REACT), NanoScience Technology Center (NSTC), University of Central Florida, Orlando, FL 32816, United States.
| | - Fei Gao
- Key Laboratory of Mesoscopic Chemistry of MOE, School of Chemistry and Chemical Engineering, Nanjing University, Jiangsu Key Laboratory of Vehicle Emissions Control, School of Environment, Center of Modern Analysis, Nanjing 210093, China
| | - Lin Dong
- Key Laboratory of Mesoscopic Chemistry of MOE, School of Chemistry and Chemical Engineering, Nanjing University, Jiangsu Key Laboratory of Vehicle Emissions Control, School of Environment, Center of Modern Analysis, Nanjing 210093, China
| | - Fudong Liu
- Department of Civil, Environmental, and Construction Engineering, Catalysis Cluster for Renewable Energy and Chemical Transformations (REACT), NanoScience Technology Center (NSTC), University of Central Florida, Orlando, FL 32816, United States.
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39
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The Review of Carbon Capture-Storage Technologies and Developing Fuel Cells for Enhancing Utilization. ENERGIES 2021. [DOI: 10.3390/en14164978] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The amount of CO2 released in the atmosphere has been at a continuous surge in the last decade, and in order to protect the environment from global warming, it is necessary to employ techniques like carbon capture. Developing technologies like Carbon Capture Utilization and Storage aims at mitigating the CO2 content from the air we breathe and has garnered immense research attention. In this review, the authors have aimed to discuss the various technologies that are being used to capture the CO2 from the atmosphere, store it and further utilize it. For utilization, researchers have developed alternatives to make profits from CO2 by converting it into an asset. The development of newer fuel cells that consume CO2 in exchange for electrical power to drive the industries and produce valuable hydrocarbons in the form of fuel has paved the path for more research in the field of carbon utilization. The primary focus on the article is to inspect the environmental and economic feasibility of novel technologies such as fuel cells, different electrochemical processes, and the integration of artificial intelligence and data science in them, which are designed for mitigating the percentage of CO2 in the air.
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40
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NH3-Selective Catalytic Reduction of NOx to N2 over Ceria Supported WOx Based Catalysts: Influence of Tungsten Content. Catalysts 2021. [DOI: 10.3390/catal11080950] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
A series of HPW/CeO2 catalysts generated from 12-tungstophosphoric acid, H3PW12O40 (HPW), supported on ceria and presenting different tungsten loadings (2, 4.5, 9, 16, and 40 wt% W) were prepared and characterized by N2 physisorption, XRD, IR, Raman, and UV-Vis. The different characterization techniques suggested that low loading of tungsten resulted in mainly isolated sites, while high tungsten loading produced polymeric or tungsten clusters. Those materials exhibited high activity in NH3-SCR of NOx into N2. Moreover, the series of experiments indicated that low loading in tungsten (2% HPW/CeO2) displayed the highest activity with a remarkable N2 selectivity (99%) at medium-high temperature (300–515 °C), owing to the high amount of monomeric tungstate coverage on the catalyst surface.
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41
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Measures to Reduce the N2O Formation at Perovskite-Based Lean NOx Trap Catalysts under Lean Conditions. Catalysts 2021. [DOI: 10.3390/catal11080917] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The net oxidising atmosphere of lean burn engines requires a special after-treatment catalyst for NOx removal from the exhaust gas. Lean NOx traps (LNT) are such kind of catalysts. To increase the efficiency of LNTs at low temperatures platinised perovskite-based infiltration composites La0.5Sr0.5Fe1-xMxO3-δ/Al2O3 with M = Nb, Ti, Zr have been developed. In general, platinum based LNT catalysts show an undesired, hazardous formation of N2O in the lean operation mode due to a competing C3H6-selective catalytic reduction (SCR) at the platinum sites. To reduce N2O emissions an additional Rh-coating, obtained by incipient wetness impregnation, besides the Pt coating and a two-layered oxidation catalyst (2 wt.% Pd/20 wt.% CeO2/alumina)-LNT constitution, has been investigated. Though the combined Rh-Pt coating shows a slightly increased NOx storage capacity (NSC) at temperatures above 300 °C, it does not decrease N2O formation. The layered oxidation catalyst-LNT system shows a decrease in N2O formation of up to 60% at 200 °C, increasing the maximum NSC up to 176 µmol/g. Furthermore, the NSC temperature range is broadened compared to that of the pure LNT catalyst, now covering a range of 250–300 °C.
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42
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Jeon SW, Song I, Lee H, Kim DH. Enhanced activity of vanadia supported on microporous titania for the selective catalytic reduction of NO with NH 3: Effect of promoters. CHEMOSPHERE 2021; 275:130105. [PMID: 33676281 DOI: 10.1016/j.chemosphere.2021.130105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Revised: 02/17/2021] [Accepted: 02/23/2021] [Indexed: 06/12/2023]
Abstract
Vanadium oxide-based catalysts are considered a promising catalyst for selective catalytic reduction (SCR) of NO with NH3, which is an effective NOx removal technology. As environmental issues have garnered more attention, however, improvements to vanadium-based SCR catalysts are strongly required. In a previous study, we found that vanadium oxide on microporous titania as a support (V/MPTiO2) has certain advantages, such as improved thermal stability and more suppressed N2O formation, over the use of conventional nanoparticle titania (DT-51) as a support. In this study, widely used promoters, such as W, Sb, and Mo, were added to V/MPTiO2 to investigate whether they have promoting effects on V/MPTiO2 as well. Among these promoters added catalysts, the W and Mo were found to have significant promoting effects on the enhancement of deNOx activities at low temperatures, while the addition of Sb to V/MPTiO2 tended to have a negative effect on the SCR activity. Based on the characterizations, including laser Raman, H2-temperature programmed reduction (H2-TPR), and in situ diffuse reflectance infrared Fourier transform (in situ DRIFT) analysis, we found that the addition of W and Mo increased the degree of polymerization in V/MPTiO2, which generated more reactive vanadia species. Hence, such changes, resulting from the addition of W and Mo promoters to V/MPTiO2, yielded enhanced catalytic activity at low temperatures.
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Affiliation(s)
- Se Won Jeon
- School of Chemical and Biological Engineering, Institute of Chemical Processes, Seoul National University, 1 Gwanak-ro Gwanak-gu, Seoul, 08826, Republic of Korea
| | - Inhak Song
- School of Chemical and Biological Engineering, Institute of Chemical Processes, Seoul National University, 1 Gwanak-ro Gwanak-gu, Seoul, 08826, Republic of Korea
| | - Hwangho Lee
- School of Chemical and Biological Engineering, Institute of Chemical Processes, Seoul National University, 1 Gwanak-ro Gwanak-gu, Seoul, 08826, Republic of Korea
| | - Do Heui Kim
- School of Chemical and Biological Engineering, Institute of Chemical Processes, Seoul National University, 1 Gwanak-ro Gwanak-gu, Seoul, 08826, Republic of Korea.
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43
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Yoshiyama Y, Hosokawa S, Tamai K, Kajino T, Yoto H, Asakura H, Teramura K, Tanaka T. NO x Storage Performance at Low Temperature over Platinum Group Metal-Free SrTiO 3-Based Material. ACS APPLIED MATERIALS & INTERFACES 2021; 13:29482-29490. [PMID: 34133123 DOI: 10.1021/acsami.1c03465] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Pt-based catalysts are commonly employed as NOx-trapping catalysts for automobiles, while perovskite oxides have received attention as Pt-free NOx-trapping catalysts. However, the NOx storage performance of perovskite catalysts is significantly inferior at low temperatures and with coexisting gases such as H2O, CO2, and SO2. This study demonstrates that NOx storage reactions proceed over redox site (Mn, Fe, and Co)-doped SrTiO3 perovskites. Among the examined catalysts, Mn-doped SrTiO3 exhibited the highest NOx storage capacity (NSC) and showed a high NSC even at a low temperature of 323 K. Moreover, the high NOx storage performance of Mn-doped SrTiO3 was retained in the presence of poisoning gases (H2O, CO2, and SO2). NO oxidation experiments revealed that the NSC of Co-doped SrTiO3 was dependent on the NO oxidation activity from NO to NO2 via lattice oxygen, which resulted in an inferior NSC at low temperatures. On the other hand, Mn-doped SrTiO3 successfully adsorbed NO molecules onto its surface at 323 K without the NO oxidation process using lattice oxygens. This unique adsorption behavior of Mn-doped SrTiO3 was concluded to be responsible for the high NSC in the presence of poisoning gases.
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Affiliation(s)
- Yuji Yoshiyama
- Department of Molecular Engineering, Graduate School of Engineering, Kyoto University, Kyotodaigaku Katsura, Nishikyo-ku, Kyoto 615-8510, Japan
| | - Saburo Hosokawa
- Department of Molecular Engineering, Graduate School of Engineering, Kyoto University, Kyotodaigaku Katsura, Nishikyo-ku, Kyoto 615-8510, Japan
- Elements Strategy Initiative for Catalysts & Batteries (ESICB), Kyoto University, 1-30 Goryo-Ohara, Nishikyo-ku, Kyoto 615-8245, Japan
| | - Kazuki Tamai
- Department of Molecular Engineering, Graduate School of Engineering, Kyoto University, Kyotodaigaku Katsura, Nishikyo-ku, Kyoto 615-8510, Japan
| | - Takanobu Kajino
- Advanced Research and Innovation Center, DENSO Corporation, 500-1 Minamiyama, Komenoki-cho, Nisshin, Aichi 470-0111, Japan
| | - Hiroaki Yoto
- Advanced Research and Innovation Center, DENSO Corporation, 500-1 Minamiyama, Komenoki-cho, Nisshin, Aichi 470-0111, Japan
| | - Hiroyuki Asakura
- Department of Molecular Engineering, Graduate School of Engineering, Kyoto University, Kyotodaigaku Katsura, Nishikyo-ku, Kyoto 615-8510, Japan
- Elements Strategy Initiative for Catalysts & Batteries (ESICB), Kyoto University, 1-30 Goryo-Ohara, Nishikyo-ku, Kyoto 615-8245, Japan
| | - Kentaro Teramura
- Department of Molecular Engineering, Graduate School of Engineering, Kyoto University, Kyotodaigaku Katsura, Nishikyo-ku, Kyoto 615-8510, Japan
- Elements Strategy Initiative for Catalysts & Batteries (ESICB), Kyoto University, 1-30 Goryo-Ohara, Nishikyo-ku, Kyoto 615-8245, Japan
| | - Tsunehiro Tanaka
- Department of Molecular Engineering, Graduate School of Engineering, Kyoto University, Kyotodaigaku Katsura, Nishikyo-ku, Kyoto 615-8510, Japan
- Elements Strategy Initiative for Catalysts & Batteries (ESICB), Kyoto University, 1-30 Goryo-Ohara, Nishikyo-ku, Kyoto 615-8245, Japan
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44
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Li M, Sakong S, Groß A. In Search of the Active Sites for the Selective Catalytic Reduction on Tungsten-Doped Vanadia Monolayer Catalysts Supported by TiO 2. ACS Catal 2021. [DOI: 10.1021/acscatal.1c01406] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Mengru Li
- Institute of Theoretical Chemistry, Ulm University, 89069 Ulm, Germany
| | - Sung Sakong
- Institute of Theoretical Chemistry, Ulm University, 89069 Ulm, Germany
| | - Axel Groß
- Institute of Theoretical Chemistry, Ulm University, 89069 Ulm, Germany
- Helmholtz Institute Ulm (HIU), Electrochemical Energy Storage, 89069 Ulm, Germany
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45
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Guan B, Jiang H, Wei Y, Liu Z, Wu X, Lin H, Huang Z. Density functional theory researches for atomic structure, properties prediction, and rational design of selective catalytic reduction catalysts: Current progresses and future perspectives. MOLECULAR CATALYSIS 2021. [DOI: 10.1016/j.mcat.2021.111704] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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46
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Lei Y, Qin C, Qiu T, Yue G, Ding M. NOx Emission Removal from a Parallel Diesel Engine Group by SCR System Based on Distributed Control Technology. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:6352-6362. [PMID: 33687198 DOI: 10.1021/acs.est.0c08767] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
In industrial application, an engine group with several engines running in parallel produces emissions, and because of its variable operation conditions and the number of engines being run, it produces great pollution. This study proposes a distributed control system (DCS) method to deal with NOx emissions from a diesel engine group. This DCS method contains several diesel engine test benches in parallel, and each engine is connected to an independent DCS unit with a selective catalytic reduction (SCR) device, and the central processing unit (CPU) distributes controlling quantities to each DCS unit. A dimensionless parameter, coefficient of difficulty K, is introduced to evaluate the NOx conversion efficiency of each unit. A control algorithm adopting the minimum K as the optimization control object to distribute the real-time NOx conversion efficiency for each unit is presented. This DCS deNOx technology has been applied in 10-engine test benches in parallel, and the results show that the DCS method not only controls NOx emissions of the engine group within the emission standard limit but also exhibits a good economic performance for suitable NOx conversion efficiency distribution and economical urea injection dose. This DCS emission control method is suitable for multiple diesel engines running in parallel under conditions of varied speeds and loads.
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Affiliation(s)
- Yan Lei
- Department of Automotive Engineering, Beijing University of Technology, Beijing 100124, China
| | - Chao Qin
- Department of Automotive Engineering, Beijing University of Technology, Beijing 100124, China
| | - Tao Qiu
- Department of Automotive Engineering, Beijing University of Technology, Beijing 100124, China
| | - Guangzhao Yue
- School of Transport and Vehicle Engineering, Shandong University of Technology, Zibo 255000, China
| | - Mengzhu Ding
- Department of Automotive Engineering, Beijing University of Technology, Beijing 100124, China
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47
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Li M, Zhang Y, Yang J, Liu X, Li Z, Zhang Q. Investigation on the urea deposit formation and thermal decomposition characteristics in the SCR aftertreatment system of a diesel engine. J Environ Sci (China) 2021; 103:157-171. [PMID: 33743898 DOI: 10.1016/j.jes.2020.10.015] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 10/16/2020] [Accepted: 10/19/2020] [Indexed: 06/12/2023]
Abstract
Selective catalytic reduction is the most efficient and reliable equipment for NOx control in current diesel engines. However, the issue of urea crystallization becomes increasingly serious with the implement of the new emissions standards. In this paper, urea deposit samples collected from engine test bed and tube furnace were characterized by thermogravimetric analysis and Fourier transform-infrared analysis to aid the comprehension of urea deposit formation. Moreover, thermogravimetric tests were conducted to disclose the effects of catalyst on the thermal decomposition processes of urea deposit. The results indicated that less temperature resistant species are formed in the engine test bed than in the tube furnace at conditions with the same temperatures. The main compositions in the World Harmonized Transient Cycle (WHTC) urea deposits are urea, cyanuric acid (CYA) and ammelide, implying that accelerating the decomposition of these species could prevent the accumulation of urea deposit. CuWTi, Cuβ and CuZSM catalysts could lead to increased yield of CYA during pure urea thermolysis. Cuβ, CuWTi and VWTi catalysts tend to promote the thermolysis of CYA while VWTi has the most significant catalytic effects on the thermal decomposition of ammelide and ammeline.
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Affiliation(s)
- Menghan Li
- Tianjin Key Laboratory of Clean Energy and Pollution Control, School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin 300401, China; School of Civil and Transportation Engineering, Hebei University of Technology, Tianjin 300401, China; National Engineering Laboratory for Mobile Source Emission Control Technology, China Automotive Technology & Research Center Co., Ltd., Tianjin 300300, China
| | - Yao Zhang
- Tianjin Key Laboratory of Clean Energy and Pollution Control, School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin 300401, China
| | - Jiancheng Yang
- Tianjin Key Laboratory of Clean Energy and Pollution Control, School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin 300401, China
| | - Xiaori Liu
- Tianjin Key Laboratory of Clean Energy and Pollution Control, School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin 300401, China; State Key Laboratory of Engines, Tianjin University, Tianjin 300072, China
| | - Zhenguo Li
- National Engineering Laboratory for Mobile Source Emission Control Technology, China Automotive Technology & Research Center Co., Ltd., Tianjin 300300, China.
| | - Qiang Zhang
- School of Energy and Power Engineering, Shandong University, Jinan, Shandong 250061, China.
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48
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Bae YK, Kim TW, Kim JR, Kim Y, Ha KS, Chae HJ. Enhanced SO2 tolerance of V2O5-Sb2O3/TiO2 catalyst for NO reduction with co-use of ammonia and liquid ammonium nitrate. J IND ENG CHEM 2021. [DOI: 10.1016/j.jiec.2021.01.029] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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49
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Tan P, Li X, Wang S, Hu Z, Lou D. Selective catalytic reduction failure of low NH3-NO ratio. Chin J Chem Eng 2021. [DOI: 10.1016/j.cjche.2020.07.055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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50
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Wang P, Jin M, Yu D, Bai S, Lei L. Evolution Mechanism of N2O for the Selective Catalytic Reduction of NOx by NH3 Over Cu-SSZ-13 Assisted Fe-BEA Catalysts. Catal Letters 2021. [DOI: 10.1007/s10562-021-03588-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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