1
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Liu J, Long J, Ge S, Bai L, Xing J, Du H, Song W, Liu X, Chen J, Li J. Catalytic Advancements in NH 3 Selective Catalytic Oxidation: The Impact of Cu-Induced Lattice Distortion in TiO 2 Crystal Structure. Chem Asian J 2025; 20:e202401139. [PMID: 39606824 DOI: 10.1002/asia.202401139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2024] [Revised: 11/14/2024] [Accepted: 11/26/2024] [Indexed: 11/29/2024]
Abstract
A series of x Cu-TiO2 obtained from the sol-gel method were tested for NH3 selective catalytic oxidation (NH3-SCO). Its performance was higher than that of supported Cu/TiO2-Im and solvent-free Cu/TiO2-SF. The catalyst exhibits better water resistance at 300 °C. XRD, Raman, and H2-TPR proved that the crystal lattice of TiO2 was deformed by Cu doping, which increased the specific surface area of the catalyst. The dispersion of the Cu component is further enhanced. The enhancement of redox potential was the key to improving catalytic activity. The NH3-TPD results prove that more acidic sites promote more active NH3 species being adsorbed and dissociated on the catalyst surface. The in-situ DRIFTs results certify that the NH3 species adsorbed on the Lewis acid sites were easier to consume than those on the Brønsted acid sites. The DFT theoretical calculation demonstrates that the doped Cu promotes the TiO2 conduction band to move closer to the Fermi level and enhances the redox performance of the catalyst. The results suggest that the Cu-TiO2 catalyst was a potential catalyst under actual working conditions, which would provide a technological reserve for the development and diffusion of ammonia slip for both mobile and fixed sources.
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Affiliation(s)
- Jun Liu
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, 100084, Beijing, P. R. China
- College of Chemistry and Chemical Engineering, Taiyuan University of Technology, Taiyuan, 030024, Shanxi, P. R. China
| | - Jisheng Long
- Shanghai SUS Environment Co., LTD., Shanghai, 201703, China
| | - Shiwei Ge
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, 100084, Beijing, P. R. China
- College of Chemistry and Chemical Engineering, Taiyuan University of Technology, Taiyuan, 030024, Shanxi, P. R. China
| | - Li Bai
- Shanghai SUS Environment Co., LTD., Shanghai, 201703, China
| | - Jiaying Xing
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, 100084, Beijing, P. R. China
| | - Hailiang Du
- Shanghai SUS Environment Co., LTD., Shanghai, 201703, China
| | - Weiwei Song
- School of Environment and Safety Engineering, North University of China, Taiyuan, 030051, Shanxi, PR China
| | - Xiaoqing Liu
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, 100084, Beijing, P. R. China
- School of Environment and Safety Engineering, North University of China, Taiyuan, 030051, Shanxi, PR China
| | - Jianjun Chen
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, 100084, Beijing, P. R. China
| | - Junhua Li
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, 100084, Beijing, P. R. China
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2
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Lv Z, Xu G, Wang Y, Yu Y, He H. Unraveling the Positive Role of WO 3 on Supported Vanadium Catalysts for NO x Reduction by Operando Spectroscopy. ACS OMEGA 2025; 10:358-367. [PMID: 39829485 PMCID: PMC11739966 DOI: 10.1021/acsomega.4c06372] [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: 07/09/2024] [Revised: 09/26/2024] [Accepted: 12/12/2024] [Indexed: 01/22/2025]
Abstract
Selective catalytic reduction of nitrogen oxides (NO x ) by ammonia (NH3-SCR) over supported vanadium catalysts is a commercial technology for NO x abatement in combustion exhaust. The addition of tungsten oxide (WO3) significantly enhances the performance of supported vanadium catalysts (V2O5/TiO2), but the mechanism underlying this enhancement remains controversial. In this study, we employed combined operando spectroscopy (DRIFTS-UV-vis-MS) to investigate the dynamic state of active sites (acid sites and redox sites) on V2O5-WO3/TiO2 during the NH3-SCR reaction. Our findings confirmed that WO3 occupied the TiO2 surface and reduced the available surface sites for V2O5 anchoring, thus promoting the agglomeration of vanadia species. This structural effect significantly improved the reducibility of VO x on V2O5-WO3/TiO2 catalysts, consequently enhancing the efficiency for NO x reduction. The heightened reducibility rendered the reoxidation of vanadia species a rate-limiting step, resulting in the presence of vanadia species in a lower oxidation state (V4+) during the NH3-SCR reaction.
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Affiliation(s)
- Zhihui Lv
- State
Key Joint Laboratory of Environment Simulation and Pollution Control,
Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- University
of Chinese Academy of Sciences, Beijing 100049, China
| | - Guangyan Xu
- State
Key Joint Laboratory of Environment Simulation and Pollution Control,
Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- University
of Chinese Academy of Sciences, Beijing 100049, China
| | - Yingjie Wang
- State
Key Joint Laboratory of Environment Simulation and Pollution Control,
Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Yunbo Yu
- State
Key Joint Laboratory of Environment Simulation and Pollution Control,
Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- University
of Chinese Academy of Sciences, Beijing 100049, China
- Center
for Excellence in Regional Atmospheric Environment, Institute of Urban
Environment, Chinese Academy of Sciences, Xiamen 361021, China
| | - Hong He
- State
Key Joint Laboratory of Environment Simulation and Pollution Control,
Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- University
of Chinese Academy of Sciences, Beijing 100049, China
- Center
for Excellence in Regional Atmospheric Environment, Institute of Urban
Environment, Chinese Academy of Sciences, Xiamen 361021, China
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3
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Guo ZY, Chen CR, Szeto KC, Taoufik M, Wang ZQ, Gong XQ. Oxygen and Electron Storage Effects in W-Modified Ceria Catalysts for Ammonia Conversion. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2024; 20:e2406818. [PMID: 39420827 DOI: 10.1002/smll.202406818] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2024] [Revised: 09/21/2024] [Indexed: 10/19/2024]
Abstract
Tungsten-modified CeO2 is an excellent catalyst for the catalytic conversion of ammonia. However, the geometric and electronic properties of this catalyst and the detailed reaction mechanisms are not well understood. In this work, the potential configurations of various monomer tungsten oxides supported on the CeO2(111) surface (WOX(x = 0-4)/CeO2(111)) are systematically studied and their relative stabilities are evaluated by using on-site Coulomb interaction corrected density functional theory calculations. Their performances are also investigated in enhancing the catalytic efficiency of NH3 adsorption and activation. It is found that the WOx clusters can always form tetrahedron-like structures on the CeO2(111) surface, and the CeO2(111) can exhibit both oxygen- and electron-storage roles to help the WOX maintain such tetrahedron-like WO4 structures and keep the W species at the highest 6+ state. Moreover, the flexibility of the tetrahedral WO4 structure leads to the preferential heterolytic NH3 dissociation at the WO sites, forming stable WNH2 and OH species. This study deepens the understanding of the unique oxygen- and electron-storage effects of the CeO2 support, it also provides valuable insights into the extraordinary catalytic properties of the W-modified CeO2 in NH3 conversion, paving the way for the rational design of more efficient CeO2-based NH3 treatment catalysts.
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Affiliation(s)
- Zi-Yi Guo
- State Key Laboratory of Green Chemical Engineering and Industrial Catalysis, Centre for Computational Chemistry and Research Institute of Industrial Catalysis, School of Chemistry and Molecular Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, China
| | - Cui-Rong Chen
- Institut de Chimie Lyon, CPE Lyon CNRS, UMR 5265 C2P2, LCOMS, Université Lyon 1, 43 Bd du 11 Novembre 1918, CEDEX, Villeurbanne, 69616, France
| | - Kai C Szeto
- Institut de Chimie Lyon, CPE Lyon CNRS, UMR 5265 C2P2, LCOMS, Université Lyon 1, 43 Bd du 11 Novembre 1918, CEDEX, Villeurbanne, 69616, France
| | - Mostafa Taoufik
- Institut de Chimie Lyon, CPE Lyon CNRS, UMR 5265 C2P2, LCOMS, Université Lyon 1, 43 Bd du 11 Novembre 1918, CEDEX, Villeurbanne, 69616, France
| | - Zhi-Qiang Wang
- State Key Laboratory of Green Chemical Engineering and Industrial Catalysis, Centre for Computational Chemistry and Research Institute of Industrial Catalysis, School of Chemistry and Molecular Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, China
| | - Xue-Qing Gong
- School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China
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4
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Zhang J, Ma Z, Cao A, Yan J, Wang Y, Yu M, Hu L, Pan S. Research progress of Mn-based low-temperature SCR denitrification catalysts. RSC Adv 2024; 14:32583-32601. [PMID: 39421682 PMCID: PMC11483454 DOI: 10.1039/d4ra05140h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2024] [Accepted: 09/11/2024] [Indexed: 10/19/2024] Open
Abstract
Selective catalytic reduction (SCR) is a efficiently nitrogen oxides removal technology from stationary source flue gases. Catalysts are key component in the technology, but currently face problems including poor low-temperature activity, narrow temperature windows, low selectivity, and susceptibility to water passivation and sulphur dioxide poisoning. To develop high-efficiency low-temperature denitrification activity catalyst, manganese-based catalysts have become a focal point of research globally for low-temperature SCR denitrification catalysts. This article investigates the denitrification efficiency of unsupported manganese-based catalysts, exploring the influence of oxidation valence, preparation method, crystallinity, crystal form, and morphology structure. It examines the catalytic performance of binary and multicomponent unsupported manganese-based catalysts, focusing on the use of transition metals and rare earth metals to modify manganese oxide. Furthermore, the synergistic effect of supported manganese-based catalysts is studied, considering metal oxides, molecular sieves, carbon materials, and other materials (composite carriers and inorganic non-metallic minerals) as supports. The reaction mechanism of low-temperature denitrification by manganese-based catalysts and the mechanism of sulphur dioxide/water poisoning are analysed in detail, and the development of practical and efficient manganese-based catalysts is considered.
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Affiliation(s)
- Jiadong Zhang
- State Key Laboratory of Clean Energy Utilization, Zhejiang University Hangzhou 310027 China +86 0571 87952822
- Institute for Carbon Neutrality, Ningbo Innovation Center, Zhejiang University Ningbo 315100 China
| | - Zengyi Ma
- State Key Laboratory of Clean Energy Utilization, Zhejiang University Hangzhou 310027 China +86 0571 87952822
- Institute for Carbon Neutrality, Ningbo Innovation Center, Zhejiang University Ningbo 315100 China
| | - Ang Cao
- State Key Laboratory of Clean Energy Utilization, Zhejiang University Hangzhou 310027 China +86 0571 87952822
| | - Jianhua Yan
- State Key Laboratory of Clean Energy Utilization, Zhejiang University Hangzhou 310027 China +86 0571 87952822
- Institute for Carbon Neutrality, Ningbo Innovation Center, Zhejiang University Ningbo 315100 China
| | - Yuelan Wang
- Shenyang Environmental Resources Exchange Shenyang 110000 China
| | - Miao Yu
- Xizi Clean Energy Equipment Manufacturing Co., Ltd Hangzhou 311500 China
| | - Linlin Hu
- Xizi Clean Energy Equipment Manufacturing Co., Ltd Hangzhou 311500 China
| | - Shaojing Pan
- Xizi Clean Energy Equipment Manufacturing Co., Ltd Hangzhou 311500 China
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5
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Wang J, Liu Y, Deng J, Jing L, Hao X, Zhang X, Yu X, Dai H. PdPtVO x/CeO 2-ZrO 2: Highly efficient catalysts with good sulfur dioxide-poisoning reversibility for the oxidative removal of ethylbenzene. J Environ Sci (China) 2024; 138:153-166. [PMID: 38135384 DOI: 10.1016/j.jes.2023.03.040] [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: 01/28/2023] [Revised: 03/30/2023] [Accepted: 03/30/2023] [Indexed: 12/24/2023]
Abstract
The PdPtVOx/CeO2-ZrO2 (PdPtVOx/CZO) catalysts were obtained by using different approaches, and their physical and chemical properties were determined by various techniques. Catalytic activities of these materials in the presence of H2O or SO2 were evaluated for the oxidation of ethylbenzene (EB). The PdPtVOx/CZO sample exhibited high catalytic activity, good hydrothermal stability, and reversible sulfur dioxide-poisoning performance, over which the specific reaction rate at 160°C, turnover frequency at 160°C (TOFPd or Pt), and apparent activation energy were 72.6 mmol/(gPt⋅sec) or 124.2 mmol/(gPd⋅sec), 14.2 sec-1 (TOFPt) or 13.1 sec-1 (TOFPd), and 58 kJ/mol, respectively. The large EB adsorption capacity, good reducibility, and strong acidity contributed to the good catalytic performance of PdPtVOx/CZO. Catalytic activity of PdPtVOx/CZO decreased when 50 ppm SO2 or (1.0 vol.% H2O + 50 ppm SO2) was added to the feedstock, but was gradually restored to its initial level after the SO2 was cut off. The good reversible sulfur dioxide-resistant performance of PdPtVOx/CZO was associated with the facts: (i) the introduction of SO2 leads to an increase in surface acidity; (ii) V can adsorb and activate SO2, thus accelerating formation of the SOx2- (x = 3 or 4) species at the V and CZO sites, weakening the adsorption of sulfur species at the PdPt active sites, and hence protecting the PdPt active sites to be not poisoned by SO2. EB oxidation over PdPtVOx/CZO might take place via the route of EB → styrene → phenyl methyl ketone → benzaldehyde → benzoic acid → maleic anhydride → CO2 and H2O.
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Affiliation(s)
- Jia Wang
- Beijing Key Laboratory for Green Catalysis and Separation, Key Laboratory of Beijing on Regional Air Pollution Control, Key Laboratory of Advanced Functional Materials, Education Ministry of China, Laboratory of Catalysis Chemistry and Nanoscience, Department of Chemical Engineering, Faculty of Environment and Life, Beijing University of Technology, Beijing 100124, China
| | - Yuxi Liu
- Beijing Key Laboratory for Green Catalysis and Separation, Key Laboratory of Beijing on Regional Air Pollution Control, Key Laboratory of Advanced Functional Materials, Education Ministry of China, Laboratory of Catalysis Chemistry and Nanoscience, Department of Chemical Engineering, Faculty of Environment and Life, Beijing University of Technology, Beijing 100124, China.
| | - Jiguang Deng
- Beijing Key Laboratory for Green Catalysis and Separation, Key Laboratory of Beijing on Regional Air Pollution Control, Key Laboratory of Advanced Functional Materials, Education Ministry of China, Laboratory of Catalysis Chemistry and Nanoscience, Department of Chemical Engineering, Faculty of Environment and Life, Beijing University of Technology, Beijing 100124, China
| | - Lin Jing
- Beijing Key Laboratory for Green Catalysis and Separation, Key Laboratory of Beijing on Regional Air Pollution Control, Key Laboratory of Advanced Functional Materials, Education Ministry of China, Laboratory of Catalysis Chemistry and Nanoscience, Department of Chemical Engineering, Faculty of Environment and Life, Beijing University of Technology, Beijing 100124, China
| | - Xiuqing Hao
- Beijing Key Laboratory for Green Catalysis and Separation, Key Laboratory of Beijing on Regional Air Pollution Control, Key Laboratory of Advanced Functional Materials, Education Ministry of China, Laboratory of Catalysis Chemistry and Nanoscience, Department of Chemical Engineering, Faculty of Environment and Life, Beijing University of Technology, Beijing 100124, China
| | - Xing Zhang
- Beijing Key Laboratory for Green Catalysis and Separation, Key Laboratory of Beijing on Regional Air Pollution Control, Key Laboratory of Advanced Functional Materials, Education Ministry of China, Laboratory of Catalysis Chemistry and Nanoscience, Department of Chemical Engineering, Faculty of Environment and Life, Beijing University of Technology, Beijing 100124, China
| | - Xiaohui Yu
- Beijing Key Laboratory for Green Catalysis and Separation, Key Laboratory of Beijing on Regional Air Pollution Control, Key Laboratory of Advanced Functional Materials, Education Ministry of China, Laboratory of Catalysis Chemistry and Nanoscience, Department of Chemical Engineering, Faculty of Environment and Life, Beijing University of Technology, Beijing 100124, China
| | - Hongxing Dai
- Beijing Key Laboratory for Green Catalysis and Separation, Key Laboratory of Beijing on Regional Air Pollution Control, Key Laboratory of Advanced Functional Materials, Education Ministry of China, Laboratory of Catalysis Chemistry and Nanoscience, Department of Chemical Engineering, Faculty of Environment and Life, Beijing University of Technology, Beijing 100124, China.
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6
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Yao P, Li J, Pei M, Liu F, Xu H, Chen Y. Engineering a PtCu Alloy to Improve N 2 Selectivity of NH 3-SCO over the Pt/SSZ-13 Catalyst. ACS APPLIED MATERIALS & INTERFACES 2024. [PMID: 38477616 DOI: 10.1021/acsami.3c16747] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/14/2024]
Abstract
Improving the N2 selectivity is always a great challenge for the selective catalytic oxidation of ammonia (NH3-SCO) over noble-metal-based (especially Pt) catalysts. In this work, Cu as an efficient promoter was introduced into the Pt/SSZ-13 catalyst to significantly improve the N2 selectivity of the NH3-SCO reaction. A PtCu alloy was formed in the PtCu/SSZ-13 catalyst, as confirmed by X-ray diffraction, transmission electron microscopy, energy dispersive spectrometry mapping, and X-ray absorption spectroscopy results. As indicated by the X-ray photoelectron spectroscopy analysis, the Pt species in the alloyed PtCu nanoparticle was mainly present in the electron-rich state on PtCu/SSZ-13, while the electron-deficient Cu and isolated Cu2+ species were both present on the surface of PtCu/SSZ-13. Due to such a unique alloyed structure with an altered oxidation state, the N2 selectivity of NH3-SCO on the PtCu/SSZ-13 catalyst was remarkably improved, while the NH3-SCO activity was kept comparable to that on Pt/SSZ-13. The reaction path was changed from the NH mechanism on Pt/SSZ-13 to both NH and internal selective catalytic reduction mechanisms on the PtCu/SSZ-13 catalyst, which was considered the main reason for the enhanced N2 selectivity. This work provides a new route to synthesize efficient alloy catalysts for optimizing the N2 selectivity of NH3-SCO for NH3 slip control in diesel exhaust purification.
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Affiliation(s)
- Pan Yao
- Institute of New Energy and Low-Carbon Technology, Sichuan University, Chengdu, Sichuan 610207, China
- Department of Civil, Environmental, and Construction Engineering, Catalysis Cluster for Renewable Energy and Chemical Transformations (REACT), Nano Science Technology Center (NSTC), University of Central Florida, Orlando, Florida 32816, United States
| | - Jiayi Li
- Institute of New Energy and Low-Carbon Technology, Sichuan University, Chengdu, Sichuan 610207, China
- Department of Civil, Environmental, and Construction Engineering, Catalysis Cluster for Renewable Energy and Chemical Transformations (REACT), Nano Science Technology Center (NSTC), University of Central Florida, Orlando, Florida 32816, United States
| | - Mingming Pei
- Sichuan Provincial Environmental Protection Environmental Catalytic Materials Engineering Technology Center, College of Chemistry, Sichuan University, Chengdu, Sichuan 610064, China
| | - Fudong Liu
- Department of Civil, Environmental, and Construction Engineering, Catalysis Cluster for Renewable Energy and Chemical Transformations (REACT), Nano Science Technology Center (NSTC), University of Central Florida, Orlando, Florida 32816, United States
| | - Haidi Xu
- Institute of New Energy and Low-Carbon Technology, Sichuan University, Chengdu, Sichuan 610207, China
| | - Yaoqiang Chen
- Institute of New Energy and Low-Carbon Technology, Sichuan University, Chengdu, Sichuan 610207, China
- Sichuan Provincial Environmental Protection Environmental Catalytic Materials Engineering Technology Center, College of Chemistry, Sichuan University, Chengdu, Sichuan 610064, China
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7
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Liu H, Gao F, Ko S, Luo N, Tang X, Duan E, Yi H, Zhou Y. Low-temperature NH 3-SCR performance of a novel Chlorella@Mn composite denitrification catalyst. J Environ Sci (China) 2024; 137:271-286. [PMID: 37980014 DOI: 10.1016/j.jes.2022.12.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2022] [Revised: 12/08/2022] [Accepted: 12/10/2022] [Indexed: 11/20/2023]
Abstract
The synthesis process of conventional Mn-based denitrification catalysts is relatively complex and expensive. In this paper, a resource application of chlorella was proposed, and a Chlorella@Mn composite denitrification catalyst was innovatively synthesized by electrostatic interaction. The Chlorella@Mn composite denitrification catalyst prepared under the optimal conditions (0.54 g/L Mn2+ concentration, 20 million chlorellas/mL concentration, 450°C calcination temperature) exhibited a well-developed pore structure and large specific surface area (122 m2/g). Compared with MnOx alone, the Chlorella@Mn composite catalyst achieved superior performance, with ∼100% NH3 selective catalytic reduction (NH3-SCR) denitrification activity at 100-225°C. The results of NH3 temperature-programmed desorption (NH3-TPD) and H2 temperature-programmed reduction (H2-TPR) showed that the catalyst had strong acid sites and good redox properties. Zeta potential testing showed that the electronegativity of the chlorella cell surface could be used to enrich with Mn2+. X-ray photoelectron spectroscopy (XPS) confirmed that Chlorella@Mn had a high content of Mn3+ and surface chemisorbed oxygen. In-situ diffuse reflectance infrared Fourier transform spectroscopy (in-situ DRIFTS) experimental results showed that both Langmuir-Hinshelwood (L-H) and Eley-Rideal (E-R) mechanisms play a role in the denitrification process on the surface of the Chlorella@Mn catalyst, where the main intermediate nitrate species is monodentate nitrite. The presence of SO2 promoted the generation and strengthening of Brønsted acid sites, but also generated more sulfate species on the surface, thereby reducing the denitrification activity of the Chlorella@Mn catalyst. The Chlorella@Mn composite catalyst had the characteristics of short preparation time, simple process and low cost, making it promising for industrial application.
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Affiliation(s)
- Hengheng Liu
- School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - Fengyu Gao
- School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, China; Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants, Beijing 100083, China
| | - Songjin Ko
- School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, China; Department of Chemistry, Pyongyang University of Architecture, Pyongyang, Democratic People's Republic of Korea
| | - Ning Luo
- School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - Xiaolong Tang
- School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, China; Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants, Beijing 100083, China.
| | - Erhong Duan
- School of Environmental Science and Engineering, University of Science and Technology Hebei, Hebei 050018, China
| | - Honghong Yi
- School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, China; Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants, Beijing 100083, China
| | - Yuansong Zhou
- School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, China; Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants, Beijing 100083, China
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8
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Zhao J, Zhang X, Yang F, Ai Y, Chen Y, Pan D. Strategy and Technical Progress of Recycling of Spent Vanadium-Titanium-Based Selective Catalytic Reduction Catalysts. ACS OMEGA 2024; 9:6036-6058. [PMID: 38371753 PMCID: PMC10870271 DOI: 10.1021/acsomega.3c07019] [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: 09/14/2023] [Revised: 12/27/2023] [Accepted: 12/28/2023] [Indexed: 02/20/2024]
Abstract
Selective catalytic reduction denitration technology, abbreviated as SCR, is essential for the removal of nitrogen oxide from the flue gas of coal-fired power stations and has been widely used. Due to the strong demand for energy and the requirements for environmental protection, a large amount of SCR catalyst waste is produced. The spent SCR catalyst contains high-grade valuable metals, and proper disposal or treatment of the SCR catalyst can protect the environment and realize resource recycling. This review focuses on the two main routes of regeneration and recycling of spent vanadium-titanium SCR catalysts that are currently most widely commercially used and summarizes in detail the technologies of recycling, high-efficiency recycling, and recycling of valuable components of spent vanadium-titanium SCR catalysts. This review also discusses in depth the future development direction of recycling spent vanadium-titanium SCR catalysts. It provides a reference for promoting recycling, which is crucial for resource recovery and green and low-carbon development.
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Affiliation(s)
- Jianying Zhao
- Institute
of Circular Economy, Faculty of Materials and Manufacturing, Beijing University of Technology, Beijing 100124, PR China
| | - Xiaoguang Zhang
- Institute
of Circular Economy, Faculty of Materials and Manufacturing, Beijing University of Technology, Beijing 100124, PR China
| | - Feihua Yang
- Solid
Waste Reuse for Building Materials State Key Laboratory, Beijing Building Materials Academy of Science Research, Beijing 100038, PR China
| | - Yonghong Ai
- Jiangxi
Minmetals Gao’an Non-ferrous Metal Co., Ltd., Gaoan 330800, PR China
| | - Yousheng Chen
- Jiangxi
Minmetals Gao’an Non-ferrous Metal Co., Ltd., Gaoan 330800, PR China
| | - Dean Pan
- Institute
of Circular Economy, Faculty of Materials and Manufacturing, Beijing University of Technology, Beijing 100124, PR China
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9
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Yan Q, Xiao J, Gui R, Chen Z, Li Y, Zhu T, Wang Q, Xin Y. Mechanistic Insight into the Promotion of the Low-Temperature NH 3-SCR Activity over NiMnFeO x LDO Catalysts: A Combined Experimental and DFT Study. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:20708-20717. [PMID: 38032314 DOI: 10.1021/acs.est.3c06849] [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: 12/01/2023]
Abstract
Mn-based catalysts have attracted much attention in the field of the low-temperature NH3 selective catalytic reduction (NH3-SCR) of NO. However, their poor SO2 resistance, low N2 selectivity, and narrow operation window limit the industrial application of Mn-based oxide catalysts. In this work, NiMnFeOx catalysts were prepared by the layered double hydroxide (LDH)-derived oxide method, and the optimized Ni0.5Mn0.5Fe0.5Ox catalyst had the best denitration activity, excellent N2 selectivity, a wider active temperature range (100-250 °C), higher thermal stability, and better H2O and/or SO2 resistance. A transient reaction revealed that Ni0.5Mn0.5Fe0.5Ox inhibited the NH3 + O2 + NOx pathway to generate N2O, which may be the main reason for its improved N2 selectivity. Combining experimental measurements and density functional theory (DFT) calculations, we elucidated at the atomic level that sulfated NiMnFeOx (111) induces the adjustment of the acidity/basicity of up and down spins and the ligand field reconfiguration of the Mn sites, which improves the overall reactivity of NiMnFeOx catalysts. This work provides atomic-level insights into the promotion of NH3-SCR activity by NiMnFeOx composite oxides, which are important for the practical design of future low-temperature SCR technologies.
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Affiliation(s)
- Qinghua Yan
- Qingdao Engineering Research Center for Rural Environment, College of Resources and Environment, Qingdao Agricultural University, Qingdao 266109, P.R. China
| | - Jiewen Xiao
- College of Environmental Science and Engineering, Beijing Forestry University, 35 Qinghua East Road, Haidian District, Beijing 100083, P.R. China
| | - Rongrong Gui
- College of Environmental Science and Engineering, Beijing Forestry University, 35 Qinghua East Road, Haidian District, Beijing 100083, P.R. China
| | - Zhenyu Chen
- Qingdao Engineering Research Center for Rural Environment, College of Resources and Environment, Qingdao Agricultural University, Qingdao 266109, P.R. China
| | - Yuran Li
- Research Center for Process Pollution Control, National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China
| | - Tingyu Zhu
- Research Center for Process Pollution Control, National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China
| | - Qiang Wang
- College of Environmental Science and Engineering, Beijing Forestry University, 35 Qinghua East Road, Haidian District, Beijing 100083, P.R. China
| | - Yanjun Xin
- Qingdao Engineering Research Center for Rural Environment, College of Resources and Environment, Qingdao Agricultural University, Qingdao 266109, P.R. China
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10
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Lee S, Ha HP, Lee JH, Kim J. Uncovering the centrality of mono-dentate SO 32-/SO 42- modifiers grafted on a metal vanadate in accelerating wet NO X reduction and poison pyrolysis. JOURNAL OF HAZARDOUS MATERIALS 2023; 460:132278. [PMID: 37619273 DOI: 10.1016/j.jhazmat.2023.132278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Revised: 08/08/2023] [Accepted: 08/11/2023] [Indexed: 08/26/2023]
Abstract
NOX rarely binds with labile oxygens of catalytic solids, whose Lewis acidic (LA) species possess higher binding strengths with NH3 (ENH3) and H2O than Brönsted acidic counterparts (BA--H+; -OH), oftentimes leading to elevate energy barrier (EBARRIER) and weaken H2O tolerance, respectively. These limit NH3-assisted wet NOX reduction via Langmuir-Hinshelwood-type or Eley-Rideal (ER)-type model on LA species, while leaving ER-type analogue on BA--H+ species proper to reduce wet NOX. Given hard-to-regulate strength/amount of -OH species and occasional association between ENH3 and EBARRIER, Ni1V2O6 (Ni1) was rationally chosen as a platform to isolate mono-dentate SO32-/SO42- species for use as BA--H+ bonds via protonation to increase collision frequency (k'APP,0) alongside with disclosure of advantages of SO32-/SO42--functionalized Ni1V2O6 (Ni1-S) over Ni1 in reducing wet NOX. Ni1-S outperformed Ni1 in achieving a larger BA--H+ quantity (k'APP,0↑), increasing H2O tolerance, and elevating oxygen mobility, thus promoting NOX reduction activity/consequences under SO2-excluding gases. V2O5-WO3 composite simulating a commercial catalyst could isolate mono-dentate SO32-/SO42- species and served as a control (V2O5-WO3-S) for comparison. Ni1-S was superior to V2O5-WO3-S in evading ammonium (bi-)sulfate (AS/ABS) poison accumulation and expediting AS/ABS pyrolysis efficiency, thereby improving AS/ABS resistance under SO2-including gases, while enhancing resistance against hydro-thermal aging.
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Affiliation(s)
- Seokhyun Lee
- Extreme Materials Research Center, Korea Institute of Science and Technology, Seoul 02792, South Korea; Department of Chemical & Biological Engineering, Korea University, Seoul 02841, South Korea
| | - Heon Phil Ha
- Extreme Materials Research Center, Korea Institute of Science and Technology, Seoul 02792, South Korea
| | - Jung-Hyun Lee
- Department of Chemical & Biological Engineering, Korea University, Seoul 02841, South Korea
| | - Jongsik Kim
- Department of Chemical Engineering (Integrated Engineering Program), Kyung Hee University, Yongin 17104, South Korea.
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11
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An D, Ji J, Cheng Q, Zhao X, Cai Y, Tan W, Tong Q, Ma K, Zou W, Sun J, Tang C, Dong L. Facile H 2O-Contributed O 2 Activation Strategy over Mn-Based SCR Catalysts to Counteract SO 2 Poisoning. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:14737-14746. [PMID: 37738479 DOI: 10.1021/acs.est.3c04314] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/24/2023]
Abstract
Mn-based catalysts preferred in low-temperature selective catalytic reduction (SCR) are susceptible to SO2 poisoning. The stubborn sulfates make insufficient O2 activation and result in deficient reactive oxygen species (ROS) for activating reaction molecules. H2O has long been regarded as an accomplice to SO2, hastening catalyst deactivation. However, such a negative impression of the SCR reaction was reversed by our recent research. Here, we reported a H2O contribution over Mn-based SCR catalysts to counteract SO2 poisoning through accessible O2 activation, in which O2 was synergistically activated with H2O to generate ROS for less deactivation and more expected regeneration. The resulting ROS benefited from the energetically favorable route supported by water-induced Ea reduction and was actively involved in the NH3 activation and NO oxidation process. Besides, ROS maintained high stability over the SO2 + H2O-deactivated γ-MnO2 catalyst throughout the mild thermal treatment, achieving complete regeneration of its own NO disposal ability. This strategy was proven to be universally applicable to other Mn-based catalysts.
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Affiliation(s)
- Dongqi An
- China State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Jiangsu Key Laboratory of Vehicle Emissions Control, Center of Modern Analysis, Key Laboratory of Mesoscopic Chemistry of MOE, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, P. R. China
| | - Jiawei Ji
- China State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Jiangsu Key Laboratory of Vehicle Emissions Control, Center of Modern Analysis, Key Laboratory of Mesoscopic Chemistry of MOE, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, P. R. China
| | - Qianni Cheng
- China State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Jiangsu Key Laboratory of Vehicle Emissions Control, Center of Modern Analysis, Key Laboratory of Mesoscopic Chemistry of MOE, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, P. R. China
| | - Xin Zhao
- China State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Jiangsu Key Laboratory of Vehicle Emissions Control, Center of Modern Analysis, Key Laboratory of Mesoscopic Chemistry of MOE, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, P. R. China
| | - Yandi Cai
- China State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Jiangsu Key Laboratory of Vehicle Emissions Control, Center of Modern Analysis, Key Laboratory of Mesoscopic Chemistry of MOE, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, P. R. China
| | - Wei Tan
- China State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Jiangsu Key Laboratory of Vehicle Emissions Control, Center of Modern Analysis, Key Laboratory of Mesoscopic Chemistry of MOE, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, P. R. China
| | - Qing Tong
- China State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Jiangsu Key Laboratory of Vehicle Emissions Control, Center of Modern Analysis, Key Laboratory of Mesoscopic Chemistry of MOE, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, P. R. China
| | - Kaili Ma
- Analysis and Testing Center, Southeast University, Nanjing 211189, P. R. China
| | - Weixin Zou
- China State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Jiangsu Key Laboratory of Vehicle Emissions Control, Center of Modern Analysis, Key Laboratory of Mesoscopic Chemistry of MOE, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, P. R. China
| | - Jingfang Sun
- China State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Jiangsu Key Laboratory of Vehicle Emissions Control, Center of Modern Analysis, Key Laboratory of Mesoscopic Chemistry of MOE, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, P. R. China
| | - Changjin Tang
- Jiangsu Province Engineering Research Center of Environmental Risk Prevention and Emergency Response Technology, School of Environment, Nanjing Normal University, Nanjing 210023, P. R. China
| | - Lin Dong
- China State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Jiangsu Key Laboratory of Vehicle Emissions Control, Center of Modern Analysis, Key Laboratory of Mesoscopic Chemistry of MOE, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, P. R. China
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12
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Fan Y, Zhang J, Yang L, Lu M, Ying T, Deng B, Dai W, Luo X, Zou J, Luo S. Enhancing SO2-shielding effect and Lewis acid sites for high efficiency in low-temperature SCR of NO with NH3: Reinforced electron-deficient extent of Fe3+ enabled by Ti4+ in Fe2O3. Sep Purif Technol 2023. [DOI: 10.1016/j.seppur.2023.123272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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13
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Protection Effect of Ammonia on CeNbTi NH3-SCR Catalyst from SO2 Poisoning. Catalysts 2022. [DOI: 10.3390/catal12111430] [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
CeNbTi catalyst was poisoned in different sulfur poisoning atmospheres at 300 °C for 6 h and then was evaluated for selective catalytic reduction (SCR) of NOx with NH3. The catalyst deactivation upon SO2 exposure was effectively inhibited in the presence of NH3. Temperature-programmed decomposition (TPD) analyses were applied to identify deposit species on the poisoned catalysts by comparison with several groups of reference samples. Diffuses reflectance infrared Fourier transform spectroscopy (DRIFTS) over CeNbTi catalysts with different poisoning pretreatments and gas purging sequences were designed to investigate the roles of NH3 in the removal of surface sulfites and sulfates. More ammonium sulfates including ammonium bisulfate and ammonium cerium sulfate were generated instead of inert cerium sulfate in these conditions. The mechanisms about the formation and transformation of surface deposits upon sulfur poisoning w/wo NH3 were explored, which provided a basis for developing Ce-based mixed oxides as SCR catalysts for stationary sources.
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14
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Catalytic performance of calcined Fe2O3/CA catalyst for NH3-SCR reaction: Role of activation temperature. J SOLID STATE CHEM 2022. [DOI: 10.1016/j.jssc.2022.123630] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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15
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Chen W, Yang S, Liu H, Huang F, Shao Q, Liu L, Sun J, Sun C, Chen D, Dong L. Single-Atom Ce-Modified α-Fe 2O 3 for Selective Catalytic Reduction of NO with NH 3. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:10442-10453. [PMID: 35749227 DOI: 10.1021/acs.est.2c02916] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
A single-atom Ce-modified α-Fe2O3 catalyst (Fe0.93Ce0.07Ox catalyst with 7% atomic percentage of Ce) was synthesized by a citric acid-assisted sol-gel method, which exhibited excellent performance for selective catalytic reduction of NOx with NH3 (NH3-SCR) over a wide operating temperature window. Remarkably, it maintained ∼93% NO conversion efficiency for 168 h in the presence of 200 ppm SO2 and 5 vol % H2O at 250 °C. The structural characterizations suggested that the introduction of Ce leads to the generation of local Fe-O-Ce sites in the FeOx matrix. Furthermore, it is critical to maintain the atomic dispersion of the Ce species to maximize the amounts of Fe-O-Ce sites in the Ce-doped FeOx catalyst. The formation of CeO2 nanoparticles due to a high doping amount of Ce species leads to a decline in catalytic performance, indicating a size-dependent catalytic behavior. Density functional theory (DFT) calculation results indicate that the formation of oxygen vacancies in the Fe-O-Ce sites is more favorable than that in the Fe-O-Fe sites in the Ce-free α-Fe2O3 catalyst. The Fe-O-Ce sites can promote the oxidation of NO to NO2 on the Fe0.93Ce0.07Ox catalyst and further facilitate the reduction of NOx by NH3. In addition, the decomposition of NH4HSO4 can occur at lower temperatures on the Fe0.93Ce0.07Ox catalyst containing atomically dispersed Ce species than on the α-Fe2O3 reference catalyst, resulting in the good SO2/H2O resistance ability in the NH3-SCR reaction.
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Affiliation(s)
- Wei Chen
- Shandong Provincial Key Laboratory of Clean Production of Fine Chemicals, College of Chemistry, Chemical Engineering and Materials Science, Institute of Materials and Clean Energy, Shandong Normal University, Jinan 250014, P. R. China
| | - Shan Yang
- Shandong Provincial Key Laboratory of Clean Production of Fine Chemicals, College of Chemistry, Chemical Engineering and Materials Science, Institute of Materials and Clean Energy, Shandong Normal University, Jinan 250014, P. R. China
| | - Hao Liu
- Shandong Provincial Key Laboratory of Clean Production of Fine Chemicals, College of Chemistry, Chemical Engineering and Materials Science, Institute of Materials and Clean Energy, Shandong Normal University, Jinan 250014, P. R. China
| | - Fang Huang
- Shandong Provincial Key Laboratory of Clean Production of Fine Chemicals, College of Chemistry, Chemical Engineering and Materials Science, Institute of Materials and Clean Energy, Shandong Normal University, Jinan 250014, P. R. China
| | - Qinghao Shao
- Shandong Provincial Key Laboratory of Clean Production of Fine Chemicals, College of Chemistry, Chemical Engineering and Materials Science, Institute of Materials and Clean Energy, Shandong Normal University, Jinan 250014, P. R. China
| | - Lichen Liu
- Department of Chemistry, Tsinghua University, Beijing 100084, P. R. China
| | - Jingfang Sun
- Jiangsu Key Laboratory of Vehicle Emissions Control, School of the Environment, Nanjing University, Nanjing 210093, P. R. China
| | - Chuanzhi Sun
- Shandong Provincial Key Laboratory of Clean Production of Fine Chemicals, College of Chemistry, Chemical Engineering and Materials Science, Institute of Materials and Clean Energy, Shandong Normal University, Jinan 250014, P. R. China
| | - Dezhan Chen
- Shandong Provincial Key Laboratory of Clean Production of Fine Chemicals, College of Chemistry, Chemical Engineering and Materials Science, Institute of Materials and Clean Energy, Shandong Normal University, Jinan 250014, P. R. China
| | - Lin Dong
- Jiangsu Key Laboratory of Vehicle Emissions Control, School of the Environment, Nanjing University, Nanjing 210093, P. R. China
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16
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Chen Y, Zhang Y, Feng X, Li J, Liu W, Ren S, Yang J, Liu Q. In situ deposition of 0D CeO 2 quantum dots on Fe 2O 3-containing solid waste NH 3-SCR catalyst: Enhancing redox and NH 3 adsorption ability. WASTE MANAGEMENT (NEW YORK, N.Y.) 2022; 149:323-332. [PMID: 35772293 DOI: 10.1016/j.wasman.2022.06.030] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Revised: 06/13/2022] [Accepted: 06/21/2022] [Indexed: 06/15/2023]
Abstract
As NOx has been turning into a crucial environmental problem, NH3-SCR technology with relatively simple device, reliable operation and low secondary pollution, has become a widely used commercial and mature de-nitration technology. However, some weaknesses restricted the further application of commercialized V2O5-WO3/TiO2 NH3-SCR catalysts, while Fe2O3-based catalysts have received much attention due to their high thermal stability, passable N2 selectivity and low cost. In this study, Fe2O3-containing solid waste derived from Zn extraction process of electric arc furnace dust was exploited as the base material for catalyst preparing. Owing to the complementary and synergistic effect of CeO2 and Fe2O3, 0D CeO2 quantum dots (CeQDs) with fully-exposed active sites, large specific surface area, and rapid charge transfer have been introduced and deposited onto Fe2O3-containing solid waste nanorods. The in-situ deposition of CeQDs led to the admirable enhancement in NH3-SCR catalytic activity, N2 selectivity and SO2 tolerance of the extremely low-cost Fe2O3 catalyst. Comprehensive characterizations and DFT calculations describing the adsorption of O2 and NH3 were applied to analyze the catalyst structure and further investigate the detailed relationship between structural properties and activity as well as reaction mechanism. This work provides new insights for the high-value utilization of iron-containing solid waste and a practical reference for boosting the performance of NH3-SCR catalysts by introducing quantum dots.
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Affiliation(s)
- Yangfan Chen
- College of Materials Science and Engineering, Chongqing University, Chongqing 400044, PR China
| | - Yuchen Zhang
- College of Materials Science and Engineering, Chongqing University, Chongqing 400044, PR China
| | - Xin Feng
- College of Materials Science and Engineering, Chongqing University, Chongqing 400044, PR China
| | - Jiangling Li
- College of Materials Science and Engineering, Chongqing University, Chongqing 400044, PR China; Chongqing Key Laboratory of Vanadium-Titanium Metallurgical and New Materials, Chongqing University, Chongqing 400044, PR China.
| | - Weizao Liu
- College of Materials Science and Engineering, Chongqing University, Chongqing 400044, PR China; Chongqing Key Laboratory of Vanadium-Titanium Metallurgical and New Materials, Chongqing University, Chongqing 400044, PR China
| | - Shan Ren
- College of Materials Science and Engineering, Chongqing University, Chongqing 400044, PR China; Chongqing Key Laboratory of Vanadium-Titanium Metallurgical and New Materials, Chongqing University, Chongqing 400044, PR China
| | - Jian Yang
- College of Materials Science and Engineering, Chongqing University, Chongqing 400044, PR China; Chongqing Key Laboratory of Vanadium-Titanium Metallurgical and New Materials, Chongqing University, Chongqing 400044, PR China
| | - Qingcai Liu
- College of Materials Science and Engineering, Chongqing University, Chongqing 400044, PR China; Chongqing Key Laboratory of Vanadium-Titanium Metallurgical and New Materials, Chongqing University, Chongqing 400044, PR China
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17
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An D, Yang Y, Zou W, Cai Y, Tong Q, Sun J, Dong L. Insight into the promotional mechanism of Cu modification towards wide-temperature NH3-SCR performance of NbCe catalyst. Chin J Chem Eng 2022. [DOI: 10.1016/j.cjche.2022.05.028] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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18
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Fang X, Qu W, Qin T, Hu X, Chen L, Ma Z, Liu X, Tang X. Abatement of Nitrogen Oxides via Selective Catalytic Reduction over Ce 1-W 1 Atom-Pair Sites. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:6631-6638. [PMID: 35500091 DOI: 10.1021/acs.est.2c00482] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Environmentally benign CeO2-WO3/TiO2 catalysts are promising alternatives to commercial toxic V2O5-WO3/TiO2 for controlling NOx emission via selective catalytic reduction (SCR), but the insufficient catalytic activity of CeO2-WO3/TiO2 catalysts is one of the obstacles in their applications because of a lack of an in-depth understanding of the CeO2-WO3 interactions. Herein, we design a Ce1-W1/TiO2 model catalyst by anchoring Ce1-W1 atom pairs on anatase TiO2(001) to investigate the synergy between Ce and W in SCR. A series of characterizations combined with density functional theory calculations and in situ diffuse-reflectance infrared Fourier-transform experiments reveal that there exists a strong electronic interaction within Ce1-W1 atom pairs, leading to a much better SCR performance of Ce1-W1/TiO2 compared with that of Ce1/TiO2 and W1/TiO2. The Ce1-W1 synergy not only shifts down the lowest unoccupied states of Ce1 near the Fermi level, thus enhancing the abilities in adsorbing and oxidizing NH3 but also makes the frontier orbital electrons of W1 delocalized, thus accelerating the activation of O2. The deep insight of the Ce-W synergy may assist in the design and development of efficient catalysts with an SCR activity as high as or even higher than V2O5-WO3/TiO2.
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Affiliation(s)
- Xue Fang
- Department of Environmental Science & Engineering, Fudan University, 2005 Songhu Road, Shanghai 200438, China
| | - Weiye Qu
- Department of Environmental Science & Engineering, Fudan University, 2005 Songhu Road, Shanghai 200438, China
| | - Tian Qin
- School of Chemistry and Chemical Engineering, In Situ Center for Physical Science, Frontiers Science Center for Transformative Molecules, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Xiaolei Hu
- Department of Environmental Science & Engineering, Fudan University, 2005 Songhu Road, Shanghai 200438, China
| | - Liwei Chen
- School of Chemistry and Chemical Engineering, In Situ Center for Physical Science, Frontiers Science Center for Transformative Molecules, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Zhen Ma
- Department of Environmental Science & Engineering, Fudan University, 2005 Songhu Road, Shanghai 200438, China
- Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China
| | - Xi Liu
- School of Chemistry and Chemical Engineering, In Situ Center for Physical Science, Frontiers Science Center for Transformative Molecules, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Xingfu Tang
- Department of Environmental Science & Engineering, Fudan University, 2005 Songhu Road, Shanghai 200438, China
- Jiangsu Collaborative Innovation Center of Atmospheric Environment & Equipment Technology, Nanjing University of Information Science & Technology, Nanjing 210044, China
- Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China
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19
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Enhanced Water and Sulfur Resistance by Sm3+ Modification of Ce–Mn/TiO2 for NH3-SCR. Catal Letters 2022. [DOI: 10.1007/s10562-022-04023-1] [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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20
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Xu G, Li H, Yu Y, He H. Dynamic Change of Active Sites of Supported Vanadia Catalysts for Selective Catalytic Reduction of Nitrogen Oxides. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:3710-3718. [PMID: 35195409 DOI: 10.1021/acs.est.1c07739] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Selective catalytic reduction of NOx by ammonia (NH3-SCR) on V2O5/TiO2 catalysts is a widely used commercial technology in power plants and diesel vehicles due to its high elimination efficiency for NOx removal. However, the mechanistic aspects of the NH3-SCR reaction, especially the active sites on the V2O5/TiO2 catalysts, are still a puzzle. Herein, using combined operando spectroscopy and density functional theory calculations, we found that the reactivity of the Lewis acid site was significantly overestimated due to its conversion to the Brønsted acid site. Such interconversion makes it challenging to measure the intrinsic reactivity of different acid sites accurately. In contrast, the abundant V-OH Brønsted acid sites govern the overall NOx reduction rate in realistic exhaust containing water vapor. Moreover, the vanadia species cycle between V5+═O and V4+-OH during NOx reduction, and the re-oxidation of V4+ species to form V5+ is the rate-determining step.
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Affiliation(s)
- Guangyan Xu
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Hao Li
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Yunbo Yu
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Hong He
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
- University of Chinese Academy of Sciences, Beijing 100049, China
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21
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Gao F, Yang C, Tang X, Yi H, Wang C. Co- or Ni-modified Sn-MnOx low-dimensional multi-oxides for high-efficient NH 3-SCR De-NOx: Performance optimization and reaction mechanism. J Environ Sci (China) 2022; 113:204-218. [PMID: 34963529 DOI: 10.1016/j.jes.2021.05.032] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 05/12/2021] [Accepted: 05/20/2021] [Indexed: 06/14/2023]
Abstract
NH3-SCR performances were explored to the relationship between structure morphology and physio-chemical properties over low-dimensional ternary Mn-based catalysts prepared by one-step synthesis method. Due to its strong oxidation performance, Sn-MnOx was prone to side reactions between NO, NH3 and O2, resulting in the generation of more NO2 and N2O, here most of N2O was driven from the non-selective oxidation of NH3, while a small part generated from the side reaction between NH3 and NO2. Co or Ni doping into Sn-MnOx as solid solution components obviously stronged the electronic interaction for actively mobilization and weakened the oxidation performance for signally reducing the selective tendency of side reactions to N2O. The optimal modification resulted in improving the surface area and enhancing the strong interaction between polyvalent cations in Co/Ni-Mn-SnO2 to provide more surface adsorbed oxygen, active sites of Mn3+ and Mn4+, high-content Sn4+ and plentiful Lewis-acidity for more active intermediates, which significantly broadened the activity window of Sn-MnOx, improved the N2 selectivity by inhibiting N2O formation, and also contributed to an acceptable resistances to water and sulfur. At low reaction temperatures, the SCR reactions over three catalysts mainly obeyed the typical Elye-rideal (E-R) routs via the reactions of adsorbed l-NHx (x = 3, 2, 1) and B-NH4+ with the gaseous NO to generate N2 but also N2O by-products. Except for the above basic E-R reactions, as increasing the reaction temperature, the main adsorbed NOx-species were bidentate nitrates that were also active in the Langmuir-Hinshelwood reactions with adsorbed l-NHx species over Co/Ni modified Mn-SnO2 catalyst.
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Affiliation(s)
- Fengyu Gao
- School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, China; Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants, University of Science and Technology Beijing, Beijing 100083, China
| | - Chen Yang
- School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - Xiaolong Tang
- School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, China; Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants, University of Science and Technology Beijing, Beijing 100083, China.
| | - Honghong Yi
- School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, China; Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants, University of Science and Technology Beijing, Beijing 100083, China
| | - Chengzhi Wang
- School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, China
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22
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Jia Z, Shen Y, Yan T, Li H, Deng J, Fang J, Zhang D. Efficient NO x Abatement over Alkali-Resistant Catalysts via Constructing Durable Dimeric VO x Species. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:2647-2655. [PMID: 35107976 DOI: 10.1021/acs.est.1c06932] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The presence of alkali metals in flue gas is still an obstacle to the practical application of catalysts for selective catalytic reduction (SCR) of NOx by NH3. Polymeric vanadyl species play an essential role in ensuring the effective NOx abatement for NH3-SCR. However, polymeric vanadyl would be conventionally deactivated by the poison of alkali metals such as potassium, and it still remains a great challenge to construct robust and stable vanadyl species. Here, it was demonstrated that a more durable dimeric VOx active site could be constructed with the assistance of triethylamine, thereby achieving alkali-resistant NOx abatement. Due to the rational construction of polymerization structures, the obtained TiO2-supported cerium vanadate catalyst featured more stable dimeric VOx species and the active sites could survive even after the poisoning of alkali metal. Moreover, the depolymerization of VOx was suppressed endowing the catalysts with more Brønsted and Lewis acid sites after the poisoning of alkali metal, which ensured the efficient NOx reduction. This work unraveled the effects of alkali metal on the polymerization state of active species and opens up a way to develop low-temperature alkali-resistant catalysts for NOx abatement.
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Affiliation(s)
- Zhaozhao Jia
- International Joint Laboratory of Catalytic Chemistry, State Key Laboratory of Advanced Special Steel, Department of Chemistry, Research Center of Nano Science and Technology, College of Sciences, Shanghai University, Shanghai 200444, China
| | - Yongjie Shen
- International Joint Laboratory of Catalytic Chemistry, State Key Laboratory of Advanced Special Steel, Department of Chemistry, Research Center of Nano Science and Technology, College of Sciences, Shanghai University, Shanghai 200444, China
| | - Tingting Yan
- International Joint Laboratory of Catalytic Chemistry, State Key Laboratory of Advanced Special Steel, Department of Chemistry, Research Center of Nano Science and Technology, College of Sciences, Shanghai University, Shanghai 200444, China
| | - Hongrui Li
- International Joint Laboratory of Catalytic Chemistry, State Key Laboratory of Advanced Special Steel, Department of Chemistry, Research Center of Nano Science and Technology, College of Sciences, Shanghai University, Shanghai 200444, China
| | - Jiang Deng
- International Joint Laboratory of Catalytic Chemistry, State Key Laboratory of Advanced Special Steel, Department of Chemistry, Research Center of Nano Science and Technology, College of Sciences, Shanghai University, Shanghai 200444, China
| | - Jianhui Fang
- International Joint Laboratory of Catalytic Chemistry, State Key Laboratory of Advanced Special Steel, Department of Chemistry, Research Center of Nano Science and Technology, College of Sciences, Shanghai University, Shanghai 200444, China
| | - Dengsong Zhang
- International Joint Laboratory of Catalytic Chemistry, State Key Laboratory of Advanced Special Steel, Department of Chemistry, Research Center of Nano Science and Technology, College of Sciences, Shanghai University, Shanghai 200444, China
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23
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Kim J, Kim DH, Park J, Jeong K, Ha HP. Decrypting Catalytic NOX Activation and Poison Fragmentation Routes Boosted by Mono- and Bi-Dentate Surface SO32–/SO42– Modifiers under a SO2-Containing Flue Gas Stream. ACS Catal 2022. [DOI: 10.1021/acscatal.1c04611] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- Jongsik Kim
- Extreme Materials Research Center, Korea Institute of Science and Technology, Seoul 02792, South Korea
| | - Dong Ho Kim
- Extreme Materials Research Center, Korea Institute of Science and Technology, Seoul 02792, South Korea
- Department of Chemical and Biological Engineering, Korea University, Seoul 02841, South Korea
| | - Jinseon Park
- Department of Physics and Chemistry, Korea Military Academy, Seoul 01805, South Korea
| | - Keunhong Jeong
- Department of Physics and Chemistry, Korea Military Academy, Seoul 01805, South Korea
| | - Heon Phil Ha
- Extreme Materials Research Center, Korea Institute of Science and Technology, Seoul 02792, South Korea
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24
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Hao C, Zhang C, Zhang J, Wu J, Yue Y, Qian G. An efficient strategy to screen an effective catalyst for NOx-SCR by deducing surface species using DRIFTS. J Colloid Interface Sci 2022; 606:677-687. [PMID: 34416457 DOI: 10.1016/j.jcis.2021.08.070] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 08/09/2021] [Accepted: 08/09/2021] [Indexed: 11/28/2022]
Abstract
HYPOTHESIS Transition metal supported TiO2 is one of the hottest catalysts in the field of selective catalytic reduction (SCR) of nitrogen oxides. Various formulas have been put forward for an enhanced activity. However, seldom work emphasizes on easy and fast screening of an effective catalyst. EXPERIMENTS In this work, Diffuse Reflection Fourier Transform Infrared (DRIFTS) screened catalyst by analyzing intermediates during SCR. FINDINGS TiO2 provided main adsorption sites for NH3 and the "Eley-Rideal" mechanism dominated the catalysis. The transition metals served as the bridge of electron transport. Moreover, the area reduction rate of adsorbed NH3 and NH4+ species in DRIFTS represented the electron-transfer rate as well as catalytic activity. In other words, a faster area reduction indicated a better SCR activity. Therefore, this work supplied a fast strategy to screen the most effective catalyst among different materials even without using a nitrogen oxides detector. At the same time, less ammonia and nitrogen oxides were used or discharged.
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Affiliation(s)
- Cuicui Hao
- SHU Center of Green Urban Mining & Industry Ecology, School of Environmental and Chemical Engineering, Shanghai University, No. 381 Nanchen Road, Shanghai 200444, PR China
| | - Chenchen Zhang
- SHU Center of Green Urban Mining & Industry Ecology, School of Environmental and Chemical Engineering, Shanghai University, No. 381 Nanchen Road, Shanghai 200444, PR China
| | - Jia Zhang
- SHU Center of Green Urban Mining & Industry Ecology, School of Environmental and Chemical Engineering, Shanghai University, No. 381 Nanchen Road, Shanghai 200444, PR China.
| | - Jianzhong Wu
- MGI of Shanghai University, Xiapu Town, Xiangdong District, Pingxiang City, Jiangxi 337022, PR China
| | - Yang Yue
- MGI of Shanghai University, Xiapu Town, Xiangdong District, Pingxiang City, Jiangxi 337022, PR China
| | - Guangren Qian
- MGI of Shanghai University, Xiapu Town, Xiangdong District, Pingxiang City, Jiangxi 337022, PR China.
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25
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Wang L, Ren Y, Yu X, Yu D, Peng C, Zhou Q, Hou J, Zhong C, Yin C, Fan X, Zhao Z, Cheng K, Chen Y, Sojka Z, Kotarba A, Wei Y, Liu J. Facile preparation, catalytic performance and reaction mechanism of MnxCo1-xOδ/3DOM-m Ti0.7Si0.2W0.1Oy catalysts for the simultaneous removal of soot and NOx. Catal Sci Technol 2022. [DOI: 10.1039/d2cy00077f] [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
In this work, three-dimensionally ordered macroporous-mesoporous Ti0.7Si0.2W0.1Oy (3DOM-m TiSiWO) supported MnxCo1-xOδ catalysts with different x values were prepared using the colloidal crystal template method and incipient wetness impregnation method. The...
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26
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Lyu M, Zou J, Liu X, Yan T, Wang P, Zhang D. Insight on the anti-poisoning mechanism of in situ coupled sulfate over iron oxide catalysts in NO x reduction. Catal Sci Technol 2022. [DOI: 10.1039/d2cy00434h] [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
In situ coupled sulfate uniquely migrated to the surface of iron oxide catalysts to capture metal poisons and thus maintained efficient adsorption and activation of NH3 and NOx reactants.
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Affiliation(s)
- Minghui Lyu
- International Joint Laboratory of Catalytic Chemistry, College of Sciences, Shanghai University, Shanghai 200444, China
| | - Jingjing Zou
- International Joint Laboratory of Catalytic Chemistry, College of Sciences, Shanghai University, Shanghai 200444, China
| | - Xiangyu Liu
- International Joint Laboratory of Catalytic Chemistry, College of Sciences, Shanghai University, Shanghai 200444, China
| | - Tingting Yan
- International Joint Laboratory of Catalytic Chemistry, College of Sciences, Shanghai University, Shanghai 200444, China
| | - Penglu Wang
- International Joint Laboratory of Catalytic Chemistry, College of Sciences, Shanghai University, Shanghai 200444, China
| | - Dengsong Zhang
- International Joint Laboratory of Catalytic Chemistry, College of Sciences, Shanghai University, Shanghai 200444, China
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27
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Liu J, Shi X, Lv Z, Yu Y, He H. Ceria–tungsten–tin oxide catalysts with superior regeneration capacity after sulfur poisoning for NH 3-SCR process. Catal Sci Technol 2022. [DOI: 10.1039/d2cy00036a] [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
A combined study on the anti-sintering ability, SO2-poisoning mechanism and thermal regeneration property of CeWSnOx catalysts for NH3-SCR reaction.
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Affiliation(s)
- Jingjing Liu
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Xiaoyan Shi
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhihui Lv
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Yunbo Yu
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- University of Chinese Academy of Sciences, Beijing 100049, China
- Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
| | - Hong He
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- University of Chinese Academy of Sciences, Beijing 100049, China
- Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
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28
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Li L, Ji J, Tan W, Song W, Wang X, Wei X, Guo K, Zhang W, Tang C, Dong L. Enhancing low-temperature NH3-SCR performance of Fe–Mn/CeO2 catalyst by Al2O3 modification. J RARE EARTH 2021. [DOI: 10.1016/j.jre.2021.08.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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29
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Abstract
This review aims to give a general overview of the recent use of tungsten-based catalysts for wide environmental applications, with first some useful background information about tungsten oxides. Tungsten oxide materials exhibit suitable behaviors for surface reactions and catalysis such as acidic properties (mainly Brønsted sites), redox and adsorption properties (due to the presence of oxygen vacancies) and a photostimulation response under visible light (2.6–2.8 eV bandgap). Depending on the operating condition of the catalytic process, each of these behaviors is tunable by controlling structure and morphology (e.g., nanoplates, nanosheets, nanorods, nanowires, nanomesh, microflowers, hollow nanospheres) and/or interactions with other compounds such as conductors (carbon), semiconductors or other oxides (e.g., TiO2) and precious metals. WOx particles can be also dispersed on high specific surface area supports. Based on these behaviors, WO3-based catalysts were developed for numerous environmental applications. This review is divided into five main parts: structure of tungsten-based catalysts, acidity of supported tungsten oxide catalysts, WO3 catalysts for DeNOx applications, total oxidation of volatile organic compounds in gas phase and gas sensors and pollutant remediation in liquid phase (photocatalysis).
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30
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Ca-Poisoning Effect on V2O5-WO3/TiO2 and V2O5-WO3-CeO2/TiO2 Catalysts with Different Vanadium Loading. Catalysts 2021. [DOI: 10.3390/catal11040445] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Ca poisoning behavior is inevitable for high-calcium content flue gas, so V2O5-WO3/TiO2 (VWT) and V2O5-WO3-CeO2/TiO2 (VWCeT) catalysts with different vanadium content have been prepared and the Ca-doped catalysts are compared in this manuscript. The result shows Ce addition can both promote the NO conversion and the alkali resistance. Lower Ca addition for 0.1VWCeT catalyst promotes its oxidability and Ce modification is more suitable for low vanadium catalysts. The total acidity and the reducibility of catalysts decline after Ca doping, and the reducibility of the active species on catalysts has been strengthened by Ce addition. CeO2 based catalysts with lower Ca loading struggle to resist sulfur poisoning, while higher Ca loading favors SO2 adsorption and also physically reduces the cerium acidification process. In the presence of SO2, additional Brønsted acid sites are formed in Ca rich catalyst. The dynamic NH3 adsorption has been investigated, shows that Ca doping content on catalyst is critical for SCR reaction, and the catalyst is more susceptible to SO2 initially in alkali flue gas during the actual application, but the sulfur resistance may increase with the alkali-poisoning effect aggravated by Ca doping.
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31
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Tan W, Liu A, Xie S, Yan Y, Shaw TE, Pu Y, Guo K, Li L, Yu S, Gao F, Liu F, Dong L. Ce-Si Mixed Oxide: A High Sulfur Resistant Catalyst in the NH 3-SCR Reaction through the Mechanism-Enhanced Process. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:4017-4026. [PMID: 33656869 DOI: 10.1021/acs.est.0c08410] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Investigating catalytic reaction mechanisms could help guide the design of catalysts. Here, aimed at improving both the catalytic performance and SO2 resistance ability of catalysts in the selective reduction of NO by NH3 (NH3-SCR), an innovative CeO2-SiO2 mixed oxide catalyst (CeSi2) was developed based on our understanding of both the sulfur poisoning and reaction mechanisms, which exhibited excellent SO2/H2O resistance ability even in the harsh working conditions (containing 500 ppm of SO2 and 5% H2O). The strong interaction between Ce and Si (Ce-O-Si) and the abundant surface hydroxyl groups on CeSi2 not only provided fruitful surface acid sites but also significantly inhibited SO2 adsorption. The NH3-SCR performance of CeSi2 was promoted by an enhanced Eley-Rideal (E-R) mechanism in which more active acid sites were preserved under the reaction conditions and gaseous NO could directly react with adsorbed NH3. This mechanism-enhanced process was even further promoted on sulfated CeSi2. This work provides a reaction mechanism-enhanced strategy to develop an environmentally friendly NH3-SCR catalyst with superior SO2 resistance.
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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, Florida 32816, United States
| | | | - 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, Florida 32816, United States
| | - Yong Yan
- School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore 637459, Singapore
| | - Thomas E Shaw
- Department of Chemistry, Catalysis Cluster for Renewable Energy and Chemical Transformations (REACT), University of Central Florida, Orlando, Florida 32816, United States
| | | | | | - Lulu Li
- School of Environmental and Chemical Engineering, Jiangsu University of Science and Technology, Zhenjiang, 212003 Jiangsu, 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, Florida 32816, United States
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32
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Yu Y, Yi X, Zhang J, Tong Z, Chen C, Ma M, He C, Wang J, Chen J, Chen B. Application of ReOx/TiO2 catalysts with excellent SO2 tolerance for the selective catalytic reduction of NOx by NH3. Catal Sci Technol 2021. [DOI: 10.1039/d1cy00467k] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The adsorption of SO2 on ReOx/TiO2 catalysts was rather weak; thus, ReOx/TiO2 catalysts exhibited excellent SO2 tolerance in the NH3-SCR reaction.
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