1
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Li G, Li G, Liao M, Liu W, Zhang H, Huang S, Huang T, Zhang S, Li Z, Peng H. Unlocking Mixed-Metal Oxides Active Centers via Acidity Regulation for K&SO 2 Poisoning Resistance: Self-Detoxification Mechanism of Zeolite-Confined deNO x Catalysts. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024. [PMID: 38828512 DOI: 10.1021/acs.est.4c03060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2024]
Abstract
Selective catalytic reduction of nitrogen oxides (NOx) with ammonia (NH3-SCR) is an efficient NOx reduction strategy, while the denitrification (deNOx) catalysts suffer from serious deactivation due to the coexistence of multiple poisoning substances, such as alkali metal (e.g., K), SO2, etc., in industrial flue gases. It is essential to understand the interaction among various poisons and their effects on the deNOx process. Herein, the ZSM-5 zeolite-confined MnSmOx mixed (MnSmOx@ZSM-5) catalyst exhibited better deNOx performance after the poisoning of K, SO2, and/or K&SO2 than the MnSmOx and MnSmOx/ZSM-5 catalysts, the deNOx activity of which at high temperature (H-T) increased significantly (>90% NOx conversion in the range of 220-480 °C). It has been demonstrated that K would occupy both redox and acidic sites, which severely reduced the reactivity of MnSmOx/ZSM-5 catalysts. The most important, K element is preferentially deposited at -OH on the surface of ZSM-5 carrier due to the electrostatic attraction (-O-K). As for the K&SO2 poisoning catalyst, SO2 preferred to be combined with the surface-deposited K (-O-K-SO2ads) according to XPS and density functional theory (DFT) results, the poisoned active sites by K would be released. The K migration behavior was induced by SO2 over K-poisoned MnSmOx@ZSM-5 catalysts, and the balance of surface redox and acidic site was regulated, like a synergistic promoter, which led to K-poisoning buffering and activity recovery. This work contributes to the understanding of the self-detoxification interaction between alkali metals (e.g., K) and SO2 on deNOx catalysts and provides a novel strategy for the adaptive use of one poisoning substance to counter another for practical NOx reduction.
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Affiliation(s)
- Guobo Li
- School of Resources and Environment, Nanchang University, Nanchang, Jiangxi 330031, PR China
| | - Gang Li
- College of Chemistry, Nanchang University, Nanchang, Jiangxi 330031, PR China
| | - Meiyuan Liao
- College of Chemistry, Nanchang University, Nanchang, Jiangxi 330031, PR China
| | - Wenming Liu
- College of Chemistry, Nanchang University, Nanchang, Jiangxi 330031, PR China
| | - Hongxiang Zhang
- School of Resources and Environment, Nanchang University, Nanchang, Jiangxi 330031, PR China
| | - Shan Huang
- School of Resources and Environment, Nanchang University, Nanchang, Jiangxi 330031, PR China
| | - Ting Huang
- School of Resources and Environment, Nanchang University, Nanchang, Jiangxi 330031, PR China
| | - Shule Zhang
- School of Chemical Engineering, Nanjing University of Science and Technology, Nanjing 210094, PR China
| | - Zhenguo Li
- National Engineering Laboratory for Mobile Source Emission Control Technology, China Automotive Technology & Research Center, Tianjin 300300, PR China
| | - Honggen Peng
- School of Resources and Environment, Nanchang University, Nanchang, Jiangxi 330031, PR China
- College of Chemistry, Nanchang University, Nanchang, Jiangxi 330031, PR China
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2
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Ullah H, Yasin S, Safeen K, Younus A, El-Bahy ZM, Safeen A, Abdou SN, Ibrahim MM. First principle study of scandium-based novel ternary half Heusler ScXGe (X = Mn and Fe) alloys: insight into the spin-polarized structural, electronic, and magnetic properties. RSC Adv 2024; 14:13605-13617. [PMID: 38665498 PMCID: PMC11043918 DOI: 10.1039/d4ra00811a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Accepted: 04/09/2024] [Indexed: 04/28/2024] Open
Abstract
The structural, electronic, and magnetic properties of novel half-Heusler alloys ScXGe (X = Mn, Fe) are investigated using the first principle full potential linearized augmented plane wave approach based on density functional theory (DFT). To attain the desired outcomes, we employed the exchange-correlation frameworks, specifically the local density approximation in combination with Perdew, Burke, and Ernzerhof's generalized gradient approximation plus the Hubbard U parameter method (GGA + U) to highlight the strong exchange-correlation interaction in these alloys. The structural parameter optimizations, whether ferromagnetic (FM) or nonmagnetic (NM), reveal that all ScXGe (where X = Mn, Fe) Heusler alloys attain their lowest ground state energy during FM optimization. The examination of the electronic properties of these alloys reveals their metallic character in both the spin-up and spin-down channels. The projected densities of states indicate that bonding is achieved through the hybridization of p-d and d-d states in all of the compounds. The investigation of the magnetic properties in ScXGe (where X = Mn, Fe) compounds indicates pronounced stability in their ferromagnetic state. Notably, the Curie temperatures for ScXGe (X = Mn, Fe) are determined to be 2177.02 K and 1656.09 K, respectively. The observation of metallic behavior and the strong ferromagnetic characteristics in ScXGe (X = Mn, Fe) half-Heusler alloys underscores their potential significance in the realm of spintronic devices. Consequently, our study serves as a robust foundation for subsequent experimental validation.
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Affiliation(s)
- Hayat Ullah
- Material Modeling and Simulation Lab, Department of Physics, Women University of Azad Jammu & Kashmir Bagh Pakistan
| | - Sadia Yasin
- Material Modeling and Simulation Lab, Department of Physics, Women University of Azad Jammu & Kashmir Bagh Pakistan
| | - Kashif Safeen
- Department of Physics, Abdul Wali Khan University Mardan 23200 Pakistan
| | - Adeel Younus
- Material Modeling and Simulation Lab, Department of Physics, Women University of Azad Jammu & Kashmir Bagh Pakistan
| | - Zeinhom M El-Bahy
- Department of Chemistry, Faculty of Science, Al-Azhar University Nasr City 11884 Cairo Egypt
| | - Akif Safeen
- Department of Physics, University of Poonch Rawalakot, AJK 12350 Pakistan
| | - Safaa N Abdou
- Department of Chemistry, Khurmah University College, Taif University Taif Saudi Arabia
| | - Mohamed M Ibrahim
- Department of Chemistry, College of Science, Taif University P. O. Box 11099 Taif 21944 Saudi Arabia
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3
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Li W, Madan SE, Réocreux R, Stamatakis M. Elucidating the Reactivity of Oxygenates on Single-Atom Alloy Catalysts. ACS Catal 2023; 13:15851-15868. [PMID: 38125982 PMCID: PMC10729050 DOI: 10.1021/acscatal.3c03954] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Revised: 10/27/2023] [Accepted: 11/01/2023] [Indexed: 12/23/2023]
Abstract
Doping isolated transition metal atoms into the surface of coinage-metal hosts to form single-atom alloys (SAAs) can significantly improve the catalytic activity and selectivity of their monometallic counterparts. These atomically dispersed dopant metals on the SAA surface act as highly active sites for various bond coupling and activation reactions. In this study, we investigate the catalytic properties of SAAs with different bimetallic combinations [Ni-, Pd-, Pt-, and Rh-doped Cu(111), Ag(111), and Au(111)] for chemistries involving oxygenates relevant to biomass reforming. Density functional theory is employed to calculate and compare the formation energies of species such as methoxy (CH3O), methanol (CH3OH), and hydroxymethyl (CH2OH), thereby understanding the stability of these adsorbates on SAAs. Activation energies and reaction energies of C-O coupling, C-H activation, and O-H activation on these oxygenates are then computed. Analysis of the data in terms of thermochemical linear scaling and Bro̷nsted-Evans-Polanyi relationship shows that some SAAs have the potential to combine weak binding with low activation energies, thereby exhibiting enhanced catalytic behavior over their monometallic counterparts for key elementary steps of oxygenate conversion. This work contributes to the discovery and development of SAA catalysts toward greener technologies, having potential applications in the transition from fossil to renewable fuels and chemicals.
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Affiliation(s)
- Weitian Li
- Thomas
Young Centre and Department of Chemical Engineering, University College London, Roberts Building, Torrington Place, London WC1E 7JE, U.K.
| | - Simran Effricia Madan
- Thomas
Young Centre and Department of Chemical Engineering, University College London, Roberts Building, Torrington Place, London WC1E 7JE, U.K.
| | - Romain Réocreux
- Thomas
Young Centre and Department of Chemical Engineering, University College London, Roberts Building, Torrington Place, London WC1E 7JE, U.K.
- Yusuf
Hamied Department of Chemistry, University
of Cambridge, Lensfield
Road, Cambridge CB2 1EW, U.K.
| | - Michail Stamatakis
- Thomas
Young Centre and Department of Chemical Engineering, University College London, Roberts Building, Torrington Place, London WC1E 7JE, U.K.
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4
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Hannagan RT, Lam HY, Réocreux R, Wang Y, Dunbar A, Lal V, Çınar V, Chen Y, Deshlahra P, Stamatakis M, Eagan NM, Sykes ECH. Investigating Spillover Energy as a Descriptor for Single-Atom Alloy Catalyst Design. J Phys Chem Lett 2023; 14:10561-10569. [PMID: 37976045 DOI: 10.1021/acs.jpclett.3c02551] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2023]
Abstract
The identification of thermodynamic descriptors of catalytic performance is essential for the rational design of heterogeneous catalysts. Here, we investigate how spillover energy, a descriptor quantifying whether intermediates are more stable at the dopant or host metal sites, can be used to design single-atom alloys (SAAs) for formic acid dehydrogenation. Using theoretical calculations, we identify NiCu as a SAA with favorable spillover energy and demonstrate that formate intermediates produced after the initial O-H activation are more stable at Ni sites where rate-determining C-H activation occurs. Surface science experiments demonstrated that NiCu(111) SAAs are more reactive than Cu(111) while they still follow the formate reaction pathway. However, reactor studies of silica-supported NiCu SAA nanoparticles showed only a modest improvement over Cu resulting from surface coverage effects. Overall, this study demonstrates the potential of engineering SAAs using spillover energy as a design parameter and highlights the importance of adsorbate-adsorbate interactions under steady-state operation.
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Affiliation(s)
- Ryan T Hannagan
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, United States
| | - Ho Yi Lam
- Department of Chemical and Biological Engineering, Tufts University, Medford, Massachusetts 02155, United States
| | - Romain Réocreux
- Thomas Young Centre and Department of Chemical Engineering, University College London, Roberts Building, Torrington Place, London WC1E 7JE, U.K
| | - Yicheng Wang
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, United States
| | - Andrew Dunbar
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, United States
| | - Vinita Lal
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, United States
| | - Volkan Çınar
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, United States
| | - Yunfan Chen
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, United States
| | - Prashant Deshlahra
- Department of Chemical and Biological Engineering, Tufts University, Medford, Massachusetts 02155, United States
| | - Michail Stamatakis
- Thomas Young Centre and Department of Chemical Engineering, University College London, Roberts Building, Torrington Place, London WC1E 7JE, U.K
| | - Nathaniel M Eagan
- Department of Chemical and Biological Engineering, Tufts University, Medford, Massachusetts 02155, United States
| | - E Charles H Sykes
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, United States
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5
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Li G, Zhang Y, Wu P, Shen K, Zhang S, Ding S. Improved activity and significant SO 2 tolerance of Sb-Pd-V oxides on N-doped TiO 2 for CB/NO x synergistic degradation. CHEMOSPHERE 2023; 329:138613. [PMID: 37030352 DOI: 10.1016/j.chemosphere.2023.138613] [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: 08/28/2022] [Revised: 02/10/2023] [Accepted: 04/03/2023] [Indexed: 05/03/2023]
Abstract
The synergistic degradation of VOCs and NOx that were emitted from the incineration of municipal and medical wastes by a single catalyst is challenging, due to the poor activity at low temperatures, and the SO2 poisoning on the active sites. Herein, N-doped TiO2 (N-TiO2) was used as the support for designing a highly efficient and stable catalyst system for CB/NOx synergistic degradation even in the presence of SO2. The prepared SbPdV/N-TiO2 catalyst, which presented excellent activity and tolerance to SO2 in the CBCO + SCR process, was investigated by a series of characterizations (such as XRD, TPD, XPS, H2-TPR and so on) as well as DFT calculations. The electronic structure of the catalyst was effectively modulated after N doping, resulting in effective charge flow between the catalyst surface and gas molecules. More importantly, the adsorption and deposition of sulfur species and reaction transient intermediates on active centers were restrained, while a new N adsorption center for NOx was provided. Abundant adsorption centers and superior redox properties ensured smooth CB/NOx synergistic degradation. The removal of CB mainly follows the L-H mechanism, while NOx elimination follows both E-R and L-H mechanisms. As a result, N doping provides a new approach to develop more advanced anti-SO2 poisoning CB/NOx synergistic catalytic removal systems for extensive applications.
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Affiliation(s)
- Guobo Li
- Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing, 210096, Jiangsu, PR China
| | - Yaping Zhang
- Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing, 210096, Jiangsu, PR China
| | - Peng Wu
- Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing, 210096, Jiangsu, PR China
| | - Kai Shen
- Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing, 210096, Jiangsu, PR China
| | - Shule Zhang
- School of Chemical Engineering, Nanjing University of Science and Technology, Nanjing, 210094, PR China
| | - Shipeng Ding
- Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing, 210096, Jiangsu, PR China.
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6
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Ingle AA, Ansari SZ, Shende DZ, Wasewar KL, Pandit AB. Progress and prospective of heterogeneous catalysts for H 2O 2 production via anthraquinone process. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:86468-86484. [PMID: 35710969 PMCID: PMC9203146 DOI: 10.1007/s11356-022-21354-z] [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: 01/04/2022] [Accepted: 06/04/2022] [Indexed: 04/16/2023]
Abstract
This paper reviews the improvement in the field of catalytic hydrogenation of 2-ethylanthraquinone to 2-ethylanthrahydroquinone for the successful production of hydrogen peroxide. Hydrogen peroxide is being used in almost all industrial areas, particularly in the chemical industry and in environmental protection, as the most promising oxidant for cleaner and environmentally safer processes. A variety of hydrogenation catalysts have been introduced for hydrogenation of 2-ethylanthraquinone in the production of hydrogen peroxide via anthraquinone (AQ) process. The aim of the present study is to describe the catalysts used in the hydrogenation of 2-ethylanthraquinone and the reaction mechanism involved with different catalytic systems. The hydrogenation of 2-ethylanthraquinone using metals, alloy, bimetallic composite, and supported metal catalyst with the structural modifications has been incorporated for the production of hydrogen peroxide. The comprehensive comparison reveals that the supported metal catalysts required lesser catalyst amount, produced lower AQ decay, and provided higher catalyst activity and selectivity. Furthermore, the replacement of conventional catalysts by metal and metal alloy-supported catalyst rises as a hydrogenation trend, enhancing by several times the catalytic performance.
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Affiliation(s)
- Anjali A. Ingle
- Advanced Separation and Analytical Laboratory (ASAL), Department of Chemical Engineering, Visvesvaraya National Institute of Technology, Nagpur, Maharashtra 440010 India
| | - Shahid Z. Ansari
- Department of Chemical Engineering, Institute of Chemical Technology (ICT), Mumbai, Maharashtra 400019 India
| | - Diwakar Z. Shende
- Advanced Separation and Analytical Laboratory (ASAL), Department of Chemical Engineering, Visvesvaraya National Institute of Technology, Nagpur, Maharashtra 440010 India
| | - Kailas L. Wasewar
- Advanced Separation and Analytical Laboratory (ASAL), Department of Chemical Engineering, Visvesvaraya National Institute of Technology, Nagpur, Maharashtra 440010 India
| | - Aniruddha B. Pandit
- Department of Chemical Engineering, Institute of Chemical Technology (ICT), Mumbai, Maharashtra 400019 India
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7
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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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8
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Hou H, Xiao J, Zhang Z, You Z, Yao Z, Zhong Q. Synergy of Mn-Fe-Al and reconstruction of chemisorption & physisorption in arsenic removal. Sep Purif Technol 2022. [DOI: 10.1016/j.seppur.2022.121748] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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9
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Xiang L, Lin F, Cai B, Li G, Zhang L, Wang Z, Yan B, Wang Y, Chen G. Catalytic ozonation of CH 2Cl 2 over hollow urchin-like MnO 2 with regulation of active oxygen by catalyst modification and ozone promotion. JOURNAL OF HAZARDOUS MATERIALS 2022; 436:129217. [PMID: 35739739 DOI: 10.1016/j.jhazmat.2022.129217] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Revised: 05/10/2022] [Accepted: 05/20/2022] [Indexed: 06/15/2023]
Abstract
This paper firstly reported efficient catalytic ozonation of CH2Cl2 (dichloromethane, DCM) at low temperature over hollow urchin-like MnO2 with high chlorine resistance. Regulations on morphologies and Cu doping, as well as ozone promotion were conducted to optimize active oxygen of MnO2 catalysts, contributing to excellent catalytic behaviors. Cu doping MnO2 with hollow urchin-like morphology attained a stable 100% DCM conversion with O3/DCM molar ratio of 10 at 120 °C. The ozone utilization rate, final products, and byproducts distribution were discussed. Abundant crystal defects, low-valance Mn/Cu, Oads, and weak acidity, as well as better low temperature reducibility contributed to its superior performance. During DCM catalytic ozonation, DCM oxidation exhibited competitive effect on O3 decomposition due to the occupation of intermediates (CH2ClO3·, O-CH2Cl, and O-CH2 -O) over active sites that should belong to O3 originally. Nevertheless, O3 decomposition exhibited synergistic effects on DCM oxidation with promotion on active oxygen. Density functional theory (DFT) calculations confirmed the positive effect on oxygen vacancy formation and O3/DCM adsorption from Cu doping. The possible mechanism for DCM catalytic ozonation included four parts, including O3/DCM adsorption, O3 activation, DCM oxidation, and electron replenishment. This paper provides new insight for catalytic elimination of chlorinated alkanes at mild conditions.
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Affiliation(s)
- Li Xiang
- School of Environmental Science and Engineering, Tianjin University/Tianjin Key Lab of Biomass/Wastes Utilization, Tianjin 300072, PR China
| | - Fawei Lin
- School of Environmental Science and Engineering, Tianjin University/Tianjin Key Lab of Biomass/Wastes Utilization, Tianjin 300072, PR China.
| | - Bohang Cai
- School of Environmental Science and Engineering, Tianjin University/Tianjin Key Lab of Biomass/Wastes Utilization, Tianjin 300072, PR China
| | - Guobo Li
- Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing 210096 Jiangsu, PR China
| | - Luyang Zhang
- School of Environmental Science and Engineering, Tianjin University/Tianjin Key Lab of Biomass/Wastes Utilization, Tianjin 300072, PR China
| | - Zhihua Wang
- State key laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, PR China
| | - Beibei Yan
- School of Environmental Science and Engineering, Tianjin University/Tianjin Key Lab of Biomass/Wastes Utilization, Tianjin 300072, PR China
| | - Yue Wang
- School of Chemical Engineering and Technology, Tianjin University, Tianjin 300134, PR China
| | - Guanyi Chen
- School of Mechanical Engineering, Tianjin University of Commerce, Tianjin 300134, PR China
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10
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Liu Y, He F, Hu Q, Huang Q, Liu X, You Z, Qiu G, Lv X. Phase, microstructure evolution, and periodic density functional theory study of reduction and nitridation of V2O3 with clean ammonia gas. ADV POWDER TECHNOL 2022. [DOI: 10.1016/j.apt.2022.103597] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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11
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Li G, Shen K, Wu P, Zhang Y, Hu Y, Xiao R, Wang B, Zhang S. SO 2 Poisoning Mechanism of the Multi-active Center Catalyst for Chlorobenzene and NO x Synergistic Degradation at Dry and Humid Environments. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:13186-13197. [PMID: 34521194 DOI: 10.1021/acs.est.1c03617] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
The performance of fresh (PdV/TiO2), sulfur poisoned (Used-S and Used-H), and regenerated (Used-RS and Used-RH) multi-active center catalysts for chlorobenzene catalytic oxidation and selective catalytic reduction (CBCO + SCR) reaction is investigated. The reaction on the catalyst surface is blocked after sulfur poisoning owing to the occupation and deposition of catalyst active centers (mainly Pd centers) by PdSO4 (and/or PdS in a dry environment) and NH4HSO4 species, especially the CBCO process. Sulfates (mainly NH4HSO4) on the sulfur poisoned catalyst surface are partially decomposed after 400 °C thermal regeneration, while the deactivation caused by the formation of PdSO4 species is irreversible. Density functional theory calculation results show that in the PdSO4 and NH4HSO4 generation paths, each step of the elementary reaction has just a small energy barrier to overcome, and the stability of the product for each elementary reaction increases gradually. Even worse, SO2 is easily combined with H2O gas molecules to form H2SO3 in a humid environment, and the energy barrier for conversion of SO32- to SO42- is just 0.041 eV. The two oxygen vacancies (VOx-1 or TiOx-1) provide adsorption sites for CBCO + SCR reaction gas molecules but do not exhibit adsorption properties for SO2, which gives a possible idea for optimization of sulfur resistance. The present work is favorable for further synergistic removal of CB/NOx by the catalyst for anti-SO2 poisoning modification and application in the manufacture industry.
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Affiliation(s)
- Guobo Li
- Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing 210096, Jiangsu, P. R. China
| | - Kai Shen
- Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing 210096, Jiangsu, P. R. China
| | - Peng Wu
- Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing 210096, Jiangsu, P. R. China
| | - Yaping Zhang
- Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing 210096, Jiangsu, P. R. China
| | - Yaqin Hu
- Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing 210096, Jiangsu, P. R. China
| | - Rui Xiao
- Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing 210096, Jiangsu, P. R. China
| | - Bing Wang
- Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing 210096, Jiangsu, P. R. China
| | - Shule Zhang
- School of Chemical Engineering, Nanjing University of Science and Technology, Nanjing 210094, P. R. China
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12
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Li M, Hua B, Wang LC, Sugar JD, Wu W, Ding Y, Li J, Ding D. Switching of metal–oxygen hybridization for selective CO2 electrohydrogenation under mild temperature and pressure. Nat Catal 2021. [DOI: 10.1038/s41929-021-00590-5] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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13
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Darby MT, Stamatakis M. Single-Atom Alloys for the Electrochemical Oxygen Reduction Reaction. Chemphyschem 2021; 22:499-508. [PMID: 33387446 PMCID: PMC7986805 DOI: 10.1002/cphc.202000869] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Revised: 12/11/2020] [Indexed: 11/09/2022]
Abstract
Single-atom alloys (SAAs) consisting of isolated transition-metal atoms doped in the surface of coinage metal hosts exhibit unique catalytic properties, harnessing the high activity of the dopant metals with the selectivity of the coinage metal hosts. Here we use density functional theory (DFT) to study SAAs comprised of Ni, Pd, Pt, Co and Rh doped into Ag and Au hosts, as candidate electrocatalysts for the oxygen reduction reaction (ORR) in proton-exchange membrane (PEM) fuel-cells. Our calculations reveal that the PdAu SAA exhibits a slightly lower theoretical overpotential, enhanced selectivity for 4-e- ORR, and tolerance to CO-poisoning compared to Pt(111). While the number of active sites of PdAu SAA is lower than that of Pt(111), the aforementioned desirable properties could bring the overall catalytic performance thereof close to that of Pt/C, indicating that the PdAu SAA could be a viable material for electrocatalytic ORR in PEM fuel-cells.
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Affiliation(s)
- Matthew T. Darby
- Thomas Young Centre and Department of Chemical EngineeringUniversity College London, Roberts BuildingTorrington PlaceLondonWC1E 7JEUK
| | - Michail Stamatakis
- Thomas Young Centre and Department of Chemical EngineeringUniversity College London, Roberts BuildingTorrington PlaceLondonWC1E 7JEUK
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14
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Wang S, Liu J, Zhang Y, Chu P, Liu H, Wang M, Duan E. Pseudo core-shell LaCoO3@MgO perovskite oxides for high performance methane catalytic oxidation. J RARE EARTH 2021. [DOI: 10.1016/j.jre.2020.02.014] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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15
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Zhu H, Li X, Shi N, Ding X, Yu Z, Zhao W, Ren H, Pan Y, Liu Y, Guo W. Density functional theory study of thiophene desulfurization and conversion of desulfurization products on the Ni(111) surface and Ni55 cluster: implication for the mechanism of reactive adsorption desulfurization over Ni/ZnO catalysts. Catal Sci Technol 2021. [DOI: 10.1039/d0cy01523g] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Density functional theory calculations were performed to study thiophene desulfurization and conversion of desulfurization products on the Ni(111) surface and Ni55 cluster.
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Affiliation(s)
- Houyu Zhu
- School of Materials Science and Engineering
- China University of Petroleum (East China)
- Qingdao
- China
| | - Xin Li
- School of Materials Science and Engineering
- China University of Petroleum (East China)
- Qingdao
- China
| | - Naiyou Shi
- School of Materials Science and Engineering
- China University of Petroleum (East China)
- Qingdao
- China
| | - Xuefei Ding
- School of Materials Science and Engineering
- China University of Petroleum (East China)
- Qingdao
- China
| | - Zehua Yu
- School of Materials Science and Engineering
- China University of Petroleum (East China)
- Qingdao
- China
| | - Wen Zhao
- School of Materials Science and Engineering
- China University of Petroleum (East China)
- Qingdao
- China
| | - Hao Ren
- School of Materials Science and Engineering
- China University of Petroleum (East China)
- Qingdao
- China
| | - Yuan Pan
- State Key Laboratory of Heavy Oil Processing
- College of Chemical Engineering
- China University of Petroleum (East China)
- Qingdao
- China
| | - Yunqi Liu
- State Key Laboratory of Heavy Oil Processing
- College of Chemical Engineering
- China University of Petroleum (East China)
- Qingdao
- China
| | - Wenyue Guo
- School of Materials Science and Engineering
- China University of Petroleum (East China)
- Qingdao
- China
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16
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Ding X, Zhu H, Ren H, Liu D, Yu Z, Shi N, Guo W. Adsorption and dehydrogenation of C 2-C 6n-alkanes over a Pt catalyst: a theoretical study on the size effects of alkane molecules and Pt substrates. Phys Chem Chem Phys 2020; 22:21835-21843. [PMID: 32966439 DOI: 10.1039/d0cp03194a] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Adsorption and dehydrogenation of C2-C6n-alkanes are investigated on a Pt substrate using density functional theory (DFT) calculations, and the size effects of alkane molecules and Pt substrates are discussed in detail. The Pt(111) surface and Pt55 cluster are chosen to represent large and small Pt nanoparticles, respectively. The C2-C6 straight-chain alkanes show no site preference on Pt(111) drifting over the surface, but prefer to locate along the edge sites of Pt55. Our results suggest that a linear relationship holds for the adsorption energies of n-alkanes against the chain length on Pt(111), in accordance with the experimental observations. Pt55 also exhibits a similar linear relationship for n-alkanes but with larger adsorption energies due to the low-coordinated Pt atoms at the edge site. For the two-step dehydrogenation from alkanes to alkenes, the first dehydrogenation reaction is the rate-determining step (RDS) on Pt(111), and a larger size of alkane molecule will lead to a lower dehydrogenation activity. While on Pt55, no RDS is present and the dehydrogenation activity oscillates slightly as the chain length of n-alkane increases. Generally, Pt55 involves lower energy barriers for most dehydrogenation steps compared to Pt(111), indicating that small Pt particles with more low-coordinated Pt atoms are more active towards alkane dehydrogenation. In addition, a clear BEP relationship is identified for all the dehydrogenation reactions of C2-C6n-alkanes on Pt substrates, and this linear relationship is independent of the particle size of the Pt substrate and the chain length of alkanes.
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Affiliation(s)
- Xuefei Ding
- School of Materials Science and Engineering, China University of Petroleum (East China), Qingdao, Shandong 266580, P. R. China.
| | - Houyu Zhu
- School of Materials Science and Engineering, China University of Petroleum (East China), Qingdao, Shandong 266580, P. R. China.
| | - Hao Ren
- School of Materials Science and Engineering, China University of Petroleum (East China), Qingdao, Shandong 266580, P. R. China.
| | - Dongyuan Liu
- School of Materials Science and Engineering, China University of Petroleum (East China), Qingdao, Shandong 266580, P. R. China.
| | - Zehua Yu
- School of Materials Science and Engineering, China University of Petroleum (East China), Qingdao, Shandong 266580, P. R. China.
| | - Naiyou Shi
- School of Materials Science and Engineering, China University of Petroleum (East China), Qingdao, Shandong 266580, P. R. China.
| | - Wenyue Guo
- School of Materials Science and Engineering, China University of Petroleum (East China), Qingdao, Shandong 266580, P. R. China.
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17
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Tian SM, Meng J, Huang J, Li QX. Two-dimensional GaTe/Bi2Se3 heterostructure: A promising direct Z-scheme water splitting photocatalyst. CHINESE J CHEM PHYS 2020. [DOI: 10.1063/1674-0068/cjcp2006081] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Affiliation(s)
- Shu-min Tian
- Department of Chemical Physics & Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei 230026, China
| | - Jie Meng
- Department of Chemical Physics & Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei 230026, China
| | - Jing Huang
- School of Materials and Chemical Engineering, Anhui Jianzhu University, Hefei 230601, China
| | - Qun-xiang Li
- Department of Chemical Physics & Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei 230026, China
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18
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Yang Z, Fengqi Z, Siyu X, Fusheng Y, Ergang Y, Xiaobing R, Zhen W, Zaoxiao Z. Investigation on Adsorption and Decomposition Properties of CL-20/FOX-7 Molecules on MgH 2(110) Surface by First-Principles. Molecules 2020; 25:E2726. [PMID: 32545500 PMCID: PMC7356053 DOI: 10.3390/molecules25122726] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 05/19/2020] [Accepted: 05/28/2020] [Indexed: 11/16/2022] Open
Abstract
Metal hydrides are regarded as promising hydrogen-supplying fuel for energetic materials while CL-20 (Hexanitrohexaazaisowurtzitane) and FOX-7 (1,1-Diamino-2,2-dinitroethylene) are typical principal components commonly used in energetic materials. Hence, it is interesting to explore the interactions between them for development of new energetic systems. In this paper, the adsorption and decomposition of CL-20 or FOX-7 molecules on the MgH2 (110) crystal surface were investigated by employing the First-Principles. In total, 18 adsorption configurations for CL-20/MgH2 (110) and 12 adsorption configurations for FOX-7/MgH2 (110) were considered. The geometric parameters for the configurations, adsorption energies, charge transfer, density of states, and decomposition mechanism were obtained and analyzed. In most of the configurations, chemical adsorption will occur. Moreover, the orientation of the nitro-group in CL-20 or FOX-7 with regard to the MgH2 (110) surface plays an important role on whether and how the energetic molecule decomposes. The adsorption and decomposition of CL-20 or FOX-7 on MgH2 could be attributed to the strong charge transfer between Mg atoms in the first layer of MgH2 (110) surface and oxygen as well as nitrogen atoms in the nitro-group of CL-20 or FOX-7 molecules.
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Affiliation(s)
- Zhang Yang
- School of Chemical Engineering and Technology, Xi’an Jiaotong University, Xi’an 710049, China; (Z.Y.); (W.Z.); (Z.Z.)
- Laboratory of Science and Technology on Combustion and Explosion, Xi’an Modern Chemistry Research Institute, Xi’an 710065, China; (Z.F.); (X.S.); (Y.E.)
| | - Zhao Fengqi
- Laboratory of Science and Technology on Combustion and Explosion, Xi’an Modern Chemistry Research Institute, Xi’an 710065, China; (Z.F.); (X.S.); (Y.E.)
| | - Xu Siyu
- Laboratory of Science and Technology on Combustion and Explosion, Xi’an Modern Chemistry Research Institute, Xi’an 710065, China; (Z.F.); (X.S.); (Y.E.)
| | - Yang Fusheng
- School of Chemical Engineering and Technology, Xi’an Jiaotong University, Xi’an 710049, China; (Z.Y.); (W.Z.); (Z.Z.)
| | - Yao Ergang
- Laboratory of Science and Technology on Combustion and Explosion, Xi’an Modern Chemistry Research Institute, Xi’an 710065, China; (Z.F.); (X.S.); (Y.E.)
| | - Ren Xiaobing
- Shanxi Northern Xing’an Chemical Industry CO.LTD, Taiyuan 030008, China;
| | - Wu Zhen
- School of Chemical Engineering and Technology, Xi’an Jiaotong University, Xi’an 710049, China; (Z.Y.); (W.Z.); (Z.Z.)
| | - Zhang Zaoxiao
- School of Chemical Engineering and Technology, Xi’an Jiaotong University, Xi’an 710049, China; (Z.Y.); (W.Z.); (Z.Z.)
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19
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Li M, Hua B, Wang LC, Zhou Z, Stowers KJ, Ding D. Discovery of single-atom alloy catalysts for CO2-to-methanol reaction by density functional theory calculations. Catal Today 2020. [DOI: 10.1016/j.cattod.2020.04.059] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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20
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Pd3Ag(111) as a Model System for Hydrogen Separation Membranes: Combined Effects of CO Adsorption and Surface Termination on the Activation of Molecular Hydrogen. Top Catal 2020. [DOI: 10.1007/s11244-020-01246-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
AbstractThe co-adsorption of hydrogen and carbon monoxide on Pd3Ag(111) alloy surfaces has been studied as a model system for Pd-Ag alloys in membrane and catalysis applications using periodic density functional theory calculations (PW91-GGA). We explored the effects of Pd–Ag surface composition, since segregation of silver towards and away from the surface has been suggested to explain the experimentally observed changes in H2 activation, CO inhibition and reactivity. We found that CO pre-adsorbed on the surface weakens the adsorption of H on Pd3Ag(111) alloy surfaces irrespective of whether the surface termination corresponds to the bulk Pd3Ag composition, or is purely Pd-terminated. A higher coverage of H with CO present is obtained for the Pd-terminated surface; this surface also exhibits a larger range of chemical potentials for co-adsorbed hydrogen and CO. The barrier for H2 activation increases with increasing CO coverage, but the surface composition has the largest impact on H2 activation at intermediate CO coverage. The results imply that Pd-based membranes with typically ~ 23 wt% Ag are less prone to CO poisoning if the surface becomes Pd-terminated.
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21
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Gao Y, Shi L, Li S, Ren Q. Mechanistic insights into higher alcohol synthesis from syngas on Rh/Cu single-atom alloy catalysts. Phys Chem Chem Phys 2020; 22:5070-5077. [DOI: 10.1039/c9cp06379j] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
DFT calculations show that C–C coupling is more favored on Rh/Cu single-atom alloy catalysts than on pure metal catalysts.
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Affiliation(s)
- Yihao Gao
- Department of Chemistry
- College of Sciences
- Shanghai University
- Shanghai 200444
- China
| | - Lei Shi
- CAS Key Laboratory of Low-Carbon Conversion Science and Engineering
- Shanghai Advanced Research Institute
- Chinese Academy of Sciences
- Shanghai 201203
- China
| | - Shenggang Li
- CAS Key Laboratory of Low-Carbon Conversion Science and Engineering
- Shanghai Advanced Research Institute
- Chinese Academy of Sciences
- Shanghai 201203
- China
| | - Qinghua Ren
- Department of Chemistry
- College of Sciences
- Shanghai University
- Shanghai 200444
- China
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22
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Guo J, Zhang L, Ma W, Chen T, Wang G, Akram N, Zhang Y, Wang J. Co(OH) 2-Modified CuO Nanoparticles Enabling High-Efficiency Photoinduced Charge Transfer toward the Water Oxidation Reaction. Ind Eng Chem Res 2019. [DOI: 10.1021/acs.iecr.9b05346] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Jia Guo
- Key Laboratory of Oil and Gas Fine Chemicals, Ministry of Education & Xinjiang Uygur Autonomous Region, College of Chemistry and Chemical Engineering of Xinjiang University, Urumqi 830046, China
- Xinjiang Industry Technical College, Urumqi 830021, China
| | - Liugen Zhang
- Key Laboratory of Oil and Gas Fine Chemicals, Ministry of Education & Xinjiang Uygur Autonomous Region, College of Chemistry and Chemical Engineering of Xinjiang University, Urumqi 830046, China
| | - Wenlan Ma
- Key Laboratory of Oil and Gas Fine Chemicals, Ministry of Education & Xinjiang Uygur Autonomous Region, College of Chemistry and Chemical Engineering of Xinjiang University, Urumqi 830046, China
| | - Tinxiang Chen
- Key Laboratory of Oil and Gas Fine Chemicals, Ministry of Education & Xinjiang Uygur Autonomous Region, College of Chemistry and Chemical Engineering of Xinjiang University, Urumqi 830046, China
| | - Guangyao Wang
- Key Laboratory of Oil and Gas Fine Chemicals, Ministry of Education & Xinjiang Uygur Autonomous Region, College of Chemistry and Chemical Engineering of Xinjiang University, Urumqi 830046, China
| | - Naeem Akram
- Key Laboratory of Oil and Gas Fine Chemicals, Ministry of Education & Xinjiang Uygur Autonomous Region, College of Chemistry and Chemical Engineering of Xinjiang University, Urumqi 830046, China
| | - Yi Zhang
- Hunan Provincial Key Laboratory of Efficient and Clean Utilization of Manganese Resources, College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, Hunan, China
| | - Jide Wang
- Key Laboratory of Oil and Gas Fine Chemicals, Ministry of Education & Xinjiang Uygur Autonomous Region, College of Chemistry and Chemical Engineering of Xinjiang University, Urumqi 830046, China
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23
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Yang Q, Hou R, Sun K. Tuning butene selectivities by Cu modification on Pd-based catalyst for the selective hydrogenation of 1,3-butadiene. J Catal 2019. [DOI: 10.1016/j.jcat.2019.04.018] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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24
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Gu H, Wang G, Zhu C, Hu Y, Zhang X, Wen W, Yang X, Wang B, Gao X, Zhan X, Li J, Ma ZF, He Q. Correlating cycle performance improvement and structural alleviation in LiMn2-xMxO4 spinel cathode materials: A systematic study on the effects of metal-ion doping. Electrochim Acta 2019. [DOI: 10.1016/j.electacta.2018.12.152] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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25
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Fang Q, Zhu B, Sun Y, Zhu Z, Xu M, Ge T. Mechanistic insight into the selective catalytic reduction of NO by NH3 over α-Fe2O3 (001): a density functional theory study. Catal Sci Technol 2019. [DOI: 10.1039/c8cy02080a] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The adsorption properties and the selective catalytic reduction mechanism of NO, NH3 and O2 molecules over the α-Fe2O3 (001) surface were studied by density functional theory.
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Affiliation(s)
- Qilong Fang
- School of Energy and Environment
- Anhui University of Technology
- Maanshan
- China
| | - Baozhong Zhu
- School of Petroleum Engineering
- Changzhou University
- Changzhou
- China
- School of Energy and Environment
| | - Yunlan Sun
- School of Petroleum Engineering
- Changzhou University
- Changzhou
- China
- School of Energy and Environment
| | - Zicheng Zhu
- School of Energy and Environment
- Anhui University of Technology
- Maanshan
- China
| | - Minggao Xu
- Center for Advanced Combustion and Energy
- University of Science and Technology of China
- Hefei
- PR China
| | - Tingting Ge
- School of Energy and Environment
- Anhui University of Technology
- Maanshan
- China
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26
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Li T, Xie Y, Wang X, Shen Q, Li J, Guo H, Xu J, Liu W. Mn promotes the rate of nucleation and growth of precipitates by increasing Frenkel pairs in Fe–Cu based alloys. RSC Adv 2019; 9:19620-19629. [PMID: 35519409 PMCID: PMC9065293 DOI: 10.1039/c9ra03226f] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Accepted: 06/11/2019] [Indexed: 12/03/2022] Open
Abstract
Fe–1.0Cu (at%) and Fe–1.2Cu–2.2Mn alloys aged at 450 °C for 0.25 h, 1 h, 2 h, and 16 h after solution treatment at 900 °C for 2 h are investigated to reveal the role of the addition of Mn on the Cu precipitates in Fe–Cu based alloys. Density functional theory (DFT) total energy calculations on point defects and their influence on Cu precipitates are also performed to understand the nucleation and growth of Cu precipitates. Experiments show that addition of Mn can slightly increase the aging peak hardness by 10 HV; by using atom probe tomography (APT) and optical microscopy, we identify that the increase in hardness derives from both grain refinement and the increase of number density of precipitates. DFT calculations show that Mn increases the formation possibility of Frenkel pairs, i.e., atomic vacancy and self-interstitial atoms, and these two types of defects both serve as nucleation sites of Cu precipitates, resulting in the increase of the nucleation centers number density, which is consistent with our APT experiments on the very initial stage of aging. Moreover, calculated results show that Mn increases the density of atomic vacancies and promotes the evolution rate of Cu precipitates, which accounts for our APT experiments where precipitates in Fe–Cu–Mn grow more quickly than in Fe–Cu. Finally, we also discuss the relationship between Mn content in reactor pressure vessel steels and its irradiation damage effects. Fe–1.0Cu (at%) and Fe–1.2Cu–2.2Mn alloys aged at 450 °C for 0.25 h, 1 h, 2 h, and 16 h after solution treatment at 900 °C for 2 h are investigated to reveal the role of the addition of Mn on the Cu precipitates in Fe–Cu based alloys.![]()
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Affiliation(s)
- Tong Li
- Institute of Materials
- School of Materials Science and Engineering
- Shanghai University
- Shanghai 200444
- China
| | - Yaoping Xie
- Institute of Materials
- School of Materials Science and Engineering
- Shanghai University
- Shanghai 200444
- China
| | - Xiaojiao Wang
- Shanghai Institute of Ceramics Academy of Science
- Shanghai 201899
- China
| | - Qin Shen
- School of Mechanical and Automotive Engineering
- Shanghai University of Engineering Science
- Shanghai 201620
- China
| | - Jiabao Li
- Institute of Materials
- School of Materials Science and Engineering
- Shanghai University
- Shanghai 200444
- China
| | - Haibo Guo
- Department of Electronic Information Materials
- School of Materials Science and Engineering
- Shanghai University
- Shanghai 200072
- China
| | - Jingxiang Xu
- College of Engineering Science and Technology
- Shanghai Ocean University
- Shanghai 201306
- China
| | - Wenqing Liu
- Institute of Materials
- School of Materials Science and Engineering
- Shanghai University
- Shanghai 200444
- China
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27
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Modification of a Shockley-Type Surface State on Pt(111) upon Deposition of Gold Thin Layers. MATERIALS 2018; 11:ma11122569. [PMID: 30562975 PMCID: PMC6316031 DOI: 10.3390/ma11122569] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Revised: 12/12/2018] [Accepted: 12/13/2018] [Indexed: 11/28/2022]
Abstract
We present a first-principles fully-relativistic study of surface and interface states in the n one monolayer (ML) Au/Pt(111) heterostructures. The modification of an unoccupied s−p-type surface state existing on a Pt(111) surface at the surface Brillouin zone center upon deposition of a few atomic Au layers is investigated. In particular, we find that the transformation process of such a surface state upon variation of the Au adlayer thickness crucially depends on the nature of the relevant quantum state in the adsorbate. When the Au adlayer consists of one or two monolayers and this relevant state has energy above the Pt(111) surface state position, the latter shifts downward upon approaching the Au adlayer. As a result, in the 1 ML Au/Pt(111) and 2 ML Au/Pt(111) heterostructures at the equilibrium adlayer position, the Pt-derived surface state experiences strong hybridization with the bulk electronic states and becomes a strong occupied resonance. In contrast, when the number n of atomic layers in the Au films increases to three or more, the Pt(111) surface state shifts upward upon reduction of the distance between the Pt(111) surface and the Au adlayer. At equilibrium, the Pt-derived surface state transforms into an unoccupied quantum-well state of the Au adlayer. This change is explained by the fact that the relevant electronic state in free-standing Au films with n≥3 has lower energy in comparison to the Pt(111) surface state.
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28
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Yuan J, Liu Y, Wu P, Zhou W. Tuning the ferromagnetism of a single layered titanium dioxide nanosheet with hole doping and uniaxial strain. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2018; 30:305804. [PMID: 29916816 DOI: 10.1088/1361-648x/aacd7d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The effects of hole doping and strain on the electronic and magnetic properties of a single layered TiO2 nanosheet were investigated here. It is found that the spontaneous magnetism can be introduced in all systems doped with low valence metal, indicating holes are the key fact to trigger local magnetic moments. Especially, a half-metal magnetism takes place when Li substitutes a Ti atom. As for the stability of dopants, the Al doping case shows lower formation energy than those of Li and Mg doping under O-rich conditions. Tuning the hole concentration, a phase transition from nonmagnetic to half-metal ferromagnetic ground state can emerge after the average spin magnetic moment reaches 1.0 µ B/hole. Furthermore, the uniaxial strain effectively adjusts the magnetism by shifting the main peak of density of states near the fermi level. The anisotropic transition of magnetic state under uniaxial tensile strain was observed due to the competition of orbital hybridization between Ti and O atoms along different crystal directions.
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Affiliation(s)
- Jian Yuan
- Tianjin Key Laboratory of Low Dimensional Materials Physics and Preparing Technology, Department of Applied Physics, School of Science, Tianjin University, Tianjin 300072, People's Republic of China
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29
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Liu L, Hu M, Liu C, Liang X, Pan Y, Ying P, Zhao Z, Gao G, He J, Tian Y. Novel carbon polymorphs with cumulative double bonds in three-dimensional sp-sp 2 hybrid framework. Phys Chem Chem Phys 2018; 20:15022-15029. [PMID: 29697115 DOI: 10.1039/c8cp00107c] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A conspicuous amount of theoretical study has been published on the properties of carbon allotropes with alternate single and triple bonds, (-C[triple bond, length as m-dash]C-)n. However, theoretical characterizations of carbon allotropes with cumulative double bonds ([double bond, length as m-dash]C[double bond, length as m-dash]C[double bond, length as m-dash])n is almost non-existent in literature. Based upon first-principles calculations, two new three-dimensional (3D) microporous carbon allotropes consisting of whorl chains connected by cumulative double bonds in a sp-sp2 hybrid framework have been proposed in this study. One of these structures, namely, Trig-C9 was obtained by an evolutionary particle swarm structural search, while the other structure, denoted as Trig-C15, was obtained by inserting double bonds into Trig-C9. Both the 3D sp-sp2 hybridized carbons have a trigonal structure with 9 and 15 atoms in the hexagonal primitive cells. The calculated results demonstrate that these polymorphs are thermodynamically, mechanically, and dynamically feasible. Trig-C9 and Trig-C15 are indirect semiconductors with band gaps of 2.70 eV and 1.25 eV, respectively. Their unique frameworks render them mechanical ductility and significant elastic anisotropy. These results open up new horizons for the exploration of new carbon phases with unique structural, mechanical, and electronic properties.
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Affiliation(s)
- Lingyu Liu
- State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004, China.
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30
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Ju J, Wang Y, Chen B, Ma J, Dong S, Chai J, Qu H, Cui L, Wu X, Cui G. Integrated Interface Strategy toward Room Temperature Solid-State Lithium Batteries. ACS APPLIED MATERIALS & INTERFACES 2018; 10:13588-13597. [PMID: 29620848 DOI: 10.1021/acsami.8b02240] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Solid-state lithium batteries have drawn wide attention to address the safety issues of power batteries. However, the development of solid-state lithium batteries is substantially limited by the poor electrochemical performances originating from the rigid interface between solid electrodes and solid-state electrolytes. In this work, a composite of poly(vinyl carbonate) and Li10SnP2S12 solid-state electrolyte is fabricated successfully via in situ polymerization to improve the rigid interface issues. The composite electrolyte presents a considerable room temperature conductivity of 0.2 mS cm-1, an electrochemical window exceeding 4.5 V, and a Li+ transport number of 0.6. It is demonstrated that solid-state lithium metal battery of LiFe0.2Mn0.8PO4 (LFMP)/composite electrolyte/Li can deliver a high capacity of 130 mA h g-1 with considerable capacity retention of 88% and Coulombic efficiency of exceeding 99% after 140 cycles at the rate of 0.5 C at room temperature. The superior electrochemical performance can be ascribed to the good compatibility of the composite electrolyte with Li metal and the integrated compatible interface between solid electrodes and the composite electrolyte engineered by in situ polymerization, which leads to a significant interfacial impedance decrease from 1292 to 213 Ω cm2 in solid-state Li-Li symmetrical cells. This work provides vital reference for improving the interface compatibility for room temperature solid-state lithium batteries.
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Affiliation(s)
- Jiangwei Ju
- Qingdao Industrial Energy Storage Research Institute, Qingdao Institute of Bioenergy and Bioprocess Technology , Chinese Academy of Sciences , Qingdao 266101 , People's Republic of China
| | - Yantao Wang
- Qingdao Industrial Energy Storage Research Institute, Qingdao Institute of Bioenergy and Bioprocess Technology , Chinese Academy of Sciences , Qingdao 266101 , People's Republic of China
- School of Future Technology , University of Chinese Academy of Sciences , Beijing 100049 , People's Republic of China
| | - Bingbing Chen
- Qingdao Industrial Energy Storage Research Institute, Qingdao Institute of Bioenergy and Bioprocess Technology , Chinese Academy of Sciences , Qingdao 266101 , People's Republic of China
| | - Jun Ma
- Qingdao Industrial Energy Storage Research Institute, Qingdao Institute of Bioenergy and Bioprocess Technology , Chinese Academy of Sciences , Qingdao 266101 , People's Republic of China
| | - Shanmu Dong
- Qingdao Industrial Energy Storage Research Institute, Qingdao Institute of Bioenergy and Bioprocess Technology , Chinese Academy of Sciences , Qingdao 266101 , People's Republic of China
| | - Jingchao Chai
- Qingdao Industrial Energy Storage Research Institute, Qingdao Institute of Bioenergy and Bioprocess Technology , Chinese Academy of Sciences , Qingdao 266101 , People's Republic of China
| | - Hongtao Qu
- Qingdao Industrial Energy Storage Research Institute, Qingdao Institute of Bioenergy and Bioprocess Technology , Chinese Academy of Sciences , Qingdao 266101 , People's Republic of China
| | - Longfei Cui
- Qingdao University of Science & Technology , Qingdao 266042 , People's Republic of China
| | - Xiuxiu Wu
- Qingdao University of Science & Technology , Qingdao 266042 , People's Republic of China
| | - Guanglei Cui
- Qingdao Industrial Energy Storage Research Institute, Qingdao Institute of Bioenergy and Bioprocess Technology , Chinese Academy of Sciences , Qingdao 266101 , People's Republic of China
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31
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Darby MT, Réocreux R, Sykes ECH, Michaelides A, Stamatakis M. Elucidating the Stability and Reactivity of Surface Intermediates on Single-Atom Alloy Catalysts. ACS Catal 2018. [DOI: 10.1021/acscatal.8b00881] [Citation(s) in RCA: 111] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Matthew T. Darby
- Thomas Young Centre and Department of Chemical Engineering, University College London, Roberts Building, Torrington Place, London WC1E 7JE, United Kingdom
| | - Romain Réocreux
- Thomas Young Centre and Department of Chemical Engineering, University College London, Roberts Building, Torrington Place, London WC1E 7JE, United Kingdom
| | - E. Charles. H. Sykes
- Department of Chemistry, Tufts University, 62 Talbot Ave., Medford, Massachusetts 02155, United States
| | - Angelos Michaelides
- Thomas Young Centre, London Centre for Nanotechnology and Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, United Kingdom
| | - Michail Stamatakis
- Thomas Young Centre and Department of Chemical Engineering, University College London, Roberts Building, Torrington Place, London WC1E 7JE, United Kingdom
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32
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Xu W, Chen C, Tang C, Li Y, Xu L. Design of Boron Doped C 2N-C 3N Coplanar Conjugated Heterostructure for Efficient HER Electrocatalysis. Sci Rep 2018; 8:5661. [PMID: 29618751 PMCID: PMC5884811 DOI: 10.1038/s41598-018-24044-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2017] [Accepted: 03/26/2018] [Indexed: 11/09/2022] Open
Abstract
Hydrogen evolution reaction (HER) via the electrocatalytic reduction of water on metal-free catalysts may become a promising method for a sustainable energy supply in the future. However, compared with noble metals or transition metals, the carbon-based metal-free electrocatalysts show poor activity. Here, a novel coplanar metal-free catalyst (C2N-C3N) was designed for the first time to achieve better efficiency for electron transfer and water reduction. Through the DFT calculations, we discovered that the unique coplanar C2N-C3N structure can promote the directional transfer of electrons from C3N to C2N under the drive of built-in electric potential in the π-conjugated plane. To achieve higher performance in HER, the single atom doping by the substitution of boron is carried out. Remarkably, after the boron is doped, the barrier in the Tafel step decreases from 2.35 eV to 0.86 eV. Our results indicate that the novel B-doped coplanar C2N-C3N structure is a promising metal-free catalyst for HER.
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Affiliation(s)
- Weiwei Xu
- Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, 199 Ren'ai Road, Suzhou, Jiangsu, 215123, PR China
| | - Chongyang Chen
- Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, 199 Ren'ai Road, Suzhou, Jiangsu, 215123, PR China
| | - Chao Tang
- Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, 199 Ren'ai Road, Suzhou, Jiangsu, 215123, PR China
| | - Youyong Li
- Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, 199 Ren'ai Road, Suzhou, Jiangsu, 215123, PR China
| | - Lai Xu
- Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, 199 Ren'ai Road, Suzhou, Jiangsu, 215123, PR China.
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33
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Abstract
Platinum group metals (PGMs) serve as highly active catalysts in a variety of heterogeneous chemical processes. Unfortunately, their high activity is accompanied by a high affinity for CO and thus, PGMs are susceptible to poisoning. Alloying PGMs with metals exhibiting lower affinity to CO could be an effective strategy toward preventing such poisoning. In this work, we use density functional theory to demonstrate this strategy, focusing on highly dilute alloys of PGMs (Pd, Pt, Rh, Ir and Ni) with poison resistant coinage metal hosts (Cu, Ag, Au), such that individual PGM atoms are dispersed at the atomic limit forming single atom alloys (SAAs). We show that compared to the pure metals, CO exhibits lower binding strength on the majority of SAAs studied, and we use kinetic Monte Carlo simulation to obtain relevant temperature programed desorption spectra, which are found to be in good agreement with experiments. Additionally, we consider the effects of CO adsorption on the structure of SAAs. We calculate segregation energies which are indicative of the stability of dopant atoms in the bulk compared to the surface layer, as well as aggregation energies to determine the stability of isolated surface dopant atoms compared to dimer and trimer configurations. Our calculations reveal that CO adsorption induces dopant atom segregation into the surface layer for all SAAs considered here, whereas aggregation and island formation may be promoted or inhibited depending on alloy constitution and CO coverage. This observation suggests the possibility of controlling ensemble effects in novel catalyst architectures through CO-induced aggregation and kinetic trapping.
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34
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Hao CM, Li Y, Zhu Q, Chen XY, Wang ZX, Li YL. Pressure-induced structural phase transition in Li4Ge. CrystEngComm 2018. [DOI: 10.1039/c8ce00783g] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The structural, dynamic, elastic, and electronic properties of Li4Ge were investigated by means of evolutionary crystal structure prediction in conjunction with first-principles calculations.
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Affiliation(s)
- Chun-Mei Hao
- School of Physics and Electronic Engineering
- Jiangsu Normal University
- Xuzhou 221116
- China
| | - Yunguo Li
- School of Physics and Electronic Engineering
- Jiangsu Normal University
- Xuzhou 221116
- China
| | - Qiang Zhu
- Department of Physics and Astronomy
- University of Nevada Las Vegas
- Las Vegas
- USA
| | - Xin-Yi Chen
- School of Physics and Electronic Engineering
- Jiangsu Normal University
- Xuzhou 221116
- China
| | - Zhan-Xin Wang
- School of Physics and Electronic Engineering
- Jiangsu Normal University
- Xuzhou 221116
- China
| | - Yan-Ling Li
- School of Physics and Electronic Engineering
- Jiangsu Normal University
- Xuzhou 221116
- China
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35
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Affiliation(s)
- Xiaofeng Li
- College of Physics and Electronic Information & Henan Key Laboratory of Electromagnetic Transformation and Detection, Luoyang Normal University, Luoyang 471934, China
| | - Feng Peng
- College of Physics and Electronic Information & Henan Key Laboratory of Electromagnetic Transformation and Detection, Luoyang Normal University, Luoyang 471934, China
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36
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A Density Functional Theory Study on the Effect of Lattice Impurities on the Electronic Structures and Reactivity of Fluorite. MINERALS 2017. [DOI: 10.3390/min7090160] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Fluorite (CaF2), a halogen elemental mineral, always co-exists with other minerals. The Ca element in fluorite is often replaced by rare earth elements (REEs), such as cerium (Ce) and yttrium (Y). In this work, the electronic structures of fluorite crystals containing REE (Ce, Th, U, and Y) impurities were studied by density functional theory (DFT). The calculated results showed that the presence of impurities increased the lattice parameter of fluorite. The impurities caused the Fermi level to shift towards the high energy direction, making the fluorite accept electrons more easily. The impurities except Y led to the occurrence of an impurities state in the valence band. The Mullinken population values of F–REE bonds were larger than that of F–Ca and F–F bonds, and F–Y bonds had the largest population value. Analysis of the frontier molecular orbital showed that the impurities contributed greatly to the lowest unoccupied molecular orbital (LUMO). The interaction between oleic acid and impurities-bearing fluorite were discussed. The results suggested that the incorporation of impurities would enhanced the reactivity of fluorite with oleic acid.
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37
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Svenum IH, Herron J, Mavrikakis M, Venvik H. Adsorbate-induced segregation in a PdAg membrane model system: Pd3Ag(111). Catal Today 2012. [DOI: 10.1016/j.cattod.2012.01.007] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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38
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Qi X, Wei Z, Li L, Ji M, Li L, Zhang Q, Xia M, Chen S, Yang L. DFT study on interaction of hydrogen with Pd(111). COMPUT THEOR CHEM 2012. [DOI: 10.1016/j.comptc.2011.10.021] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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39
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Kučera J, Gross A. Reduced Pd density of states in Pd/SAM/Au junctions: the role of adsorbed hydrogen atoms. Phys Chem Chem Phys 2012; 14:2353-61. [DOI: 10.1039/c2cp22740a] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Affiliation(s)
- Jan Kučera
- Institute for Theoretical Chemistry, Ulm University, D-89069 Ulm, Germany
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40
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Ahmed F, Alam MK, Miura R, Suzuki A, Tsuboi H, Hatakeyama N, Endou A, Takaba H, Kubo M, Miyamoto A. Modeling of hydrogen vacancy for dissociative adsorption of H2 on Pd (111) surface by a quantum chemical molecular dynamics. Catal Today 2011. [DOI: 10.1016/j.cattod.2010.10.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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41
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Lee HW, Chang CM. Size effect of Pd clusters on hydrogen adsorption. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2011; 23:045503. [PMID: 21406888 DOI: 10.1088/0953-8984/23/4/045503] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The size effect of Pd clusters on hydrogen adsorption was investigated by density functional theory calculations. From molecular dynamics simulations, we found that the hydrogen molecules were dissociatively adsorbed on the Pd clusters; the most stable adsorption site was the hollow site. We also found that the adsorption energy increased as the size of Pd clusters decreased. These results were in good agreement with experimental findings. By analyzing the electronic structure, we found that the d-band center shifted toward the Fermi energy as the size of the Pd cluster decreased. This shift resulted in stronger hydrogen bonding.
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Affiliation(s)
- Hung-Wen Lee
- Department of Physics, National Dong Hwa University, Hualien 974, Taiwan
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42
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43
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Pieczyrak B, González C, Jelínek P, Pérez R, Ortega J, Flores F. Mechanical and electrical properties of stretched clean and H-contaminated Pd-nanowires. NANOTECHNOLOGY 2008; 19:335711. [PMID: 21730637 DOI: 10.1088/0957-4484/19/33/335711] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We analyze theoretically the formation of stretched Pd-nanowires and their interaction with hydrogen. In our approach, we simulate the nanowire stretching process using a first-principles molecular-dynamics method to obtain realistic atomic geometries of the contact in its final stages before the nanowire breaks. The electrical conductance of the nanowire is also calculated at each point of the deformation path. For the clean Pd-nanowire in the last stages of the deformation process we find that the nanowire develops, first, a one-atom-neck and, at the end, a dimer whose bond is finally broken. For these atomic configurations, the calculated electrical conductances are in good agreement with the experimental evidence. The interaction with hydrogen is analyzed adsorbing one or two H atoms on the Pd-nanowire for different configurations along the stretching process. In the case of one H atom we obtain geometries with conductances in the range 0.8-1.4G(0), while for two H atoms we find conductance plateaus with values ∼0.5G(0) and ∼1.0G(0). These results are in excellent agreement with the experimental evidence for nanocontact breaking in an H(2) atmosphere and indicate that the conductance peak around 0.5G(0) observed experimentally is associated with nanowires where two H atoms have been adsorbed.
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Affiliation(s)
- B Pieczyrak
- Departamento de Física Teórica de la Materia Condensada, Universidad Autónoma de Madrid, E-28049, Spain. Institute of Experimental Physics, University of Wroclaw, plac Maksa Borna 9, 50-204 Wroclaw, Poland
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44
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Abstract
The adsorptions of K and Cs on Pd(111) were studied by the density functional calculations within the generalized gradient approximation. The site preference, bonding character, work function, and electron structure of the system were analyzed. For K and Cs adsorption, the hcp hollow site was found to be preferred for all the coverages investigated. The calculated adsorption geometries for (2 x 2) and (square root 3 x square root 3)R30 degrees phases are both in reasonable agreement with the observed results. The decrease of the work function upon the adsorption of K and Cs can be attributed to a dipole moment associated with the polarized adsorbate atom, which is characterized by depletion of the electron charge in the alkali metal layer and a charge accumulation in the interface region. Our results indicate that the bonding of alkali metal with the Pd(111) surface has a mixed ionic and metallic bond character at low coverage and a metallic bond of covalent character at high coverage.
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Affiliation(s)
- Wenzhen Lai
- Institute of Theoretical and Computational Chemistry, Key Laboratory of Mesoscopic Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China
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45
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Giordano L, Di Piazza L, Trioni M, Montalenti F. Theoretical evidence for fast H-divacancy rotation on H/Pd(111). Chem Phys Lett 2004. [DOI: 10.1016/j.cplett.2004.10.085] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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46
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Cruz A, Bertin V, Poulain E, Benitez JI, Castillo S. Theoretical study of the H2 reaction with a Pt4 (111) cluster. J Chem Phys 2004; 120:6222-8. [PMID: 15267509 DOI: 10.1063/1.1630298] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The C(s) symmetry reaction of the H(2) molecule on a Pt(4) (111) clusters, has been studied using ab initio multiconfiguration self-consistent field plus extensive multireference configuration interaction variational and perturbative calculations. The H(2) interaction by the vertex and by the base of a tetrahedral Pt(4) cluster were studied in ground and excited triplet and singlet states (closed and open shells), where the reaction curves are obtained through many avoided crossings. The Pt(4) cluster captures and activates the hydrogen molecule; it shows a similar behavior compared with other Pt(n) (n=1,2,3) systems. The Pt(4) cluster in their lowest five open and closed shell electronic states: (3)B(2), (1)B(2), (1)A(1) (3)A(1), (1)A(1), respectively, may capture and dissociate the H(2) molecule without activation barriers for the hydrogen molecule vertex approach. For the threefolded site reaction, i.e., by the base, the situation is different, the hydrogen adsorption presents some barriers. The potential energy minima occur outside and inside the cluster, with strong activation of the H-H bond. In all cases studied, the Pt(4) cluster does not absorb the hydrogen molecule.
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Affiliation(s)
- A Cruz
- Departamento de Quimica, CBI, UAM-I, A.P. 55-534, Mexico Distrito Federal 09340 Mexico
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47
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Pérez Jigato M, Coussens B, King DA. The crystalline surfaces of β-PdH{111}: Ideal surface terminations of a stoichiometric bulk compound relevant to heterogeneous catalysis. J Chem Phys 2003. [DOI: 10.1063/1.1528911] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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48
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Efremenko I. Implication of palladium geometric and electronic structures to hydrogen activation on bulk surfaces and clusters. ACTA ACUST UNITED AC 2001. [DOI: 10.1016/s1381-1169(01)00144-3] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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49
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Busnengo HF, Salin A, Dong W. Representation of the 6D potential energy surface for a diatomic molecule near a solid surface. J Chem Phys 2000. [DOI: 10.1063/1.481377] [Citation(s) in RCA: 243] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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50
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Electronic Factors Governing Ethylene Hydrogenation and Dehydrogenation Activity of Pseudomorphic PdML/Re(0001), PdML/Ru(0001), Pd(111), and PdML/Au(111) Surfaces. J Catal 2000. [DOI: 10.1006/jcat.1999.2724] [Citation(s) in RCA: 320] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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