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Álvarez-García A, Molina LM, Garzón IL. O 2 activation by subnanometer Re-Pt clusters supported on TiO 2(110): exploring adsorption sites. Phys Chem Chem Phys 2024; 26:15902-15915. [PMID: 38775219 DOI: 10.1039/d4cp01118j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2024]
Abstract
Activation of O2 by subnanometer metal clusters is a fundamental step in the reactivity and oxidation processes of single-cluster catalysts. In this work, we examine the adsorption and dissociation of O2 on RenPtm (n + m = 5) clusters supported on rutile TiO2(110) using DFT calculations. The adhesion energies of RenPtm clusters on the support are high, indicating significant stability of the supported clusters. Furthermore, the bimetallic Re-Pt clusters attach to the surface through the Re atoms. The oxygen molecule was adsorbed on three sites of the supported systems: the metal cluster, the surface, and the interface. At the metal cluster site, the O2 molecule binds strongly to RenPtm clusters, especially on the Re-rich clusters. O2 activation occurs by charge transfer from the metal atoms to the molecule. The dissociation of O2 on the RenPtm clusters is an exothermic process with low barriers. As a result, sub-nanometer Re-Pt clusters can be susceptible to oxidation. Similar results are obtained at the metal-support interface, where both the surface and cluster transfer charge to O2. To surface sites, molecular oxygen is adsorbed onto the Ti5c atoms with moderate adsorption energies. The polarons, which are produced by the interaction between the metal cluster and the surface, participate in the activation of the molecule. However, dissociating O2 in these sites is challenging due to the endothermic nature of the process and the high energy barriers involved. Our findings provide novel insights into the reactivity of supported clusters, specifically regarding the O2 activation by Re-Pt clusters on rutile TiO2(110).
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Affiliation(s)
- Andrés Álvarez-García
- Instituto de Física, Universidad Nacional Autónoma de México, Apartado Postal 20-364, Ciudad de México 01000, Mexico.
| | - Luis M Molina
- Departamento de Física Teórica, Atómica y Optica, Universidad de Valladolid, E-47011 Valladolid, Spain
| | - Ignacio L Garzón
- Instituto de Física, Universidad Nacional Autónoma de México, Apartado Postal 20-364, Ciudad de México 01000, Mexico.
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2
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Liu Q, Du S, Liu T, Gong L, Wu Y, Lin J, Yang P, Huang G, Li M, Wu Y, Zhou Y, Li Y, Tao L, Wang S. Efficient Low-temperature Hydrogen Production by Electrochemical-assisted Methanol Steam Reforming. Angew Chem Int Ed Engl 2024; 63:e202315157. [PMID: 38143245 DOI: 10.1002/anie.202315157] [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: 10/09/2023] [Revised: 12/04/2023] [Accepted: 12/22/2023] [Indexed: 12/26/2023]
Abstract
Methanol steam reforming (MSR) provides an alternative way for efficient production and safe transportation of hydrogen but requires harsh conditions and complicated purification processes. In this work, an efficient electrochemical-assisted MSR reaction for pure H2 production at lower temperature (~140 °C) is developed by coupling the electrocatalysis reaction into the MSR in a polymer electrolyte membrane electrolysis reactor. By electrochemically assisted, the two critical steps including the methanol dehydrogenation and water-gas shift reaction are accelerated, which is attributed to decreasing the methanol dehydrogenation energy and promoting the dissociation of H2 O to OH* by the applied potential. Furthermore, the reduced H2 partial pressure by the hydrogen oxidation and reduction process further promotes MSR. The combination of these advantages not only efficiently decreases the MSR temperature but also achieves the high rate of hydrogen production of 505 mmol H2 g Pt -1 h-1 with exceptionally high H2 selectivity (99 %) at 180 °C and a low voltage (0.4 V), and the productivity is about 30-fold than that of traditional MSR. This study opens up a new avenue to design novel electrolysis cells for hydrogen production.
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Affiliation(s)
- Qie Liu
- State Key Laboratory of Chemo/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, Hunan, 410082, P. R. China
| | - Shiqian Du
- State Key Laboratory of Chemo/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, Hunan, 410082, P. R. China
| | - Tianyang Liu
- Jiangsu Key Laboratory of New Power Batteries, Jiangsu Collaborative Innovation Centre of Biomedical Functional Materials, School of Chemistry and Materials Science, Nanjing Normal University, Nanjing, Jiangsu, 210023, P. R. China
| | - Liyuan Gong
- State Key Laboratory of Chemo/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, Hunan, 410082, P. R. China
| | - Yujie Wu
- State Key Laboratory of Chemo/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, Hunan, 410082, P. R. China
| | - Jiaqi Lin
- State Key Laboratory of Chemo/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, Hunan, 410082, P. R. China
| | - Pupu Yang
- State Key Laboratory of Chemo/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, Hunan, 410082, P. R. China
| | - Gen Huang
- State Key Laboratory of Chemo/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, Hunan, 410082, P. R. China
| | - Miaoyu Li
- State Key Laboratory of Chemo/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, Hunan, 410082, P. R. China
| | - Yandong Wu
- State Key Laboratory of Chemo/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, Hunan, 410082, P. R. China
| | - Yangyang Zhou
- State Key Laboratory of Chemo/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, Hunan, 410082, P. R. China
| | - Yafei Li
- Jiangsu Key Laboratory of New Power Batteries, Jiangsu Collaborative Innovation Centre of Biomedical Functional Materials, School of Chemistry and Materials Science, Nanjing Normal University, Nanjing, Jiangsu, 210023, P. R. China
| | - Li Tao
- State Key Laboratory of Chemo/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, Hunan, 410082, P. R. China
- Greater Bay Area Institute for Innovation, Hunan University, Guangzhou, 511300, P. R. China
| | - Shuangyin Wang
- State Key Laboratory of Chemo/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, Hunan, 410082, P. R. China
- Greater Bay Area Institute for Innovation, Hunan University, Guangzhou, 511300, P. R. China
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3
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Liu Y, Li L, Zhang R, Guo Y, Wang H, Ge Q, Zhu X. Synergetic enhancement of activity and selectivity for reverse water gas shift reaction on Pt-Re/SiO2 catalysts. J CO2 UTIL 2022. [DOI: 10.1016/j.jcou.2022.102128] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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4
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Yang Y, Shen T, Xu X. Towards the rational design of Pt-based alloy catalysts for the low-temperature water-gas shift reaction: from extended surfaces to single atom alloys. Chem Sci 2022; 13:6385-6396. [PMID: 35733891 PMCID: PMC9159103 DOI: 10.1039/d2sc01729f] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Accepted: 05/04/2022] [Indexed: 12/15/2022] Open
Abstract
The rational design of Pt-based catalysts for the low-temperature water-gas-shift (LT-WGS) reaction is an active research field because of its important role played in the fuel cell-based hydrogen economy, especially in mobile applications. Previous theoretical analyses have suggested that Pt alloys, leading to a weaker CO binding affinity than the Pt metal, could help alleviate CO poisoning and thus should be promising catalysts of the LT-WGS reaction. However, experimental research along this line was rather ineffective in the past decade. In the present work, we employed the state-of-the-art kinetic Monte Carlo (KMC) simulations to examine the influences of the electronic effect by introducing sub-surface alloys and/or core–shell structures, and the synergetic effect by introducing single atom alloys on the catalytic performance of Pt-alloy catalysts. Our KMC simulations have highlighted the importance of the OH binding affinity on the catalyst surfaces to reduce the barrier of water dissociation as the rate determining step, instead of the CO binding affinity as has been emphasized before in conventional mean-field kinetic models. Along this new direction of catalyst design, we found that Pt–Ru synergetic effects can significantly increase the activity of the Pt metal, leading to Ru1–3@Pt alloys with a tetrahedron site of one surface-three subsurface Ru atoms on the Pt host, showing a turnover frequency of about five orders of magnitude higher than the Pt metal. KMC simulations show that decreasing the barrier of H2O decomposition is more beneficial than decreasing the CO binding affinity in LT-WGS, while the latter was overemphasized by MF-MKM. Here Ru1–3@Pt alloy is proposed as a promising catalyst.![]()
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Affiliation(s)
- Yuqi Yang
- Collaborative Innovation Center of Chemistry for Energy Materials, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, MOE Key Laboratory of Computational Physical Sciences, Department of Chemistry, Fudan University Shanghai 200433 People's Republic of China
| | - Tonghao Shen
- Collaborative Innovation Center of Chemistry for Energy Materials, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, MOE Key Laboratory of Computational Physical Sciences, Department of Chemistry, Fudan University Shanghai 200433 People's Republic of China
| | - Xin Xu
- Collaborative Innovation Center of Chemistry for Energy Materials, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, MOE Key Laboratory of Computational Physical Sciences, Department of Chemistry, Fudan University Shanghai 200433 People's Republic of China
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5
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Chattoraj J, Hamadicharef B, Kong JF, Pargi MK, Zeng Y, Poh CK, Chen L, Gao F, Tan TL. Theory‐guided machine learning to predict the performance of noble metal catalysts in the water‐gas shift reaction. ChemCatChem 2022. [DOI: 10.1002/cctc.202200355] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Joyjit Chattoraj
- IHPC: Institute of High Performance Computing Computing & Intelligence 1 Fusionopolis Way#16-16Connexis North Tower 138632 Singapore SINGAPORE
| | - Brahim Hamadicharef
- IHPC: Institute of High Performance Computing Computing and Intelligence SINGAPORE
| | - Jian Feng Kong
- IHPC: Institute of High Performance Computing Materials Science and Chemistry SINGAPORE
| | - Mohan Kashyap Pargi
- IHPC: Institute of High Performance Computing Computing and Intelligence SINGAPORE
| | - Yingzhi Zeng
- IHPC: Institute of High Performance Computing Materials Science and Chemistry SINGAPORE
| | - Chee Kok Poh
- Institute of Sustainability for Chemicals Energy and Environment Catalysis and Reactor Design SINGAPORE
| | - Luwei Chen
- Institute of Sustainability for Chemicals Energy and Environment Catalysis and Reactor Design SINGAPORE
| | - Fei Gao
- IHPC: Institute of High Performance Computing Computing and Intelligence SINGAPORE
| | - Teck Leong Tan
- IHPC: Institute of High Performance Computing Materials Science and Chemistry SINGAPORE
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6
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Gálvez-González LE, Posada-Amarillas A, Paz-Borbón LO. Structure, Energetics, and Thermal Behavior of Bimetallic Re-Pt Clusters. J Phys Chem A 2021; 125:4294-4305. [PMID: 34008972 DOI: 10.1021/acs.jpca.0c11303] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Bimetallic Re-Pt is a widely used catalyst in petroleum reforming to obtain high-octane gasoline, but experimental and theoretical information of such systems at the subnanometer scale-namely, as cluster aggregates-is currently lacking. Thus, in this work, we performed a density functional theory-based global optimization study to determine the physicochemical properties of the most stable Re-Pt gas-phase clusters up to six atoms for all compositions. Our results indicate that in these putative global minima (GM) geometries, Re atoms tend to aggregate, while most Pt atoms remain separated from each other. This is even observed in Pt-rich clusters-an indication of the strength of the Re-Re and Re-Pt bonds over pure Pt-Pt ones-due to a strong, directional hybridization of the Re half-filled 5d and the nearly full Pt 5d states. We observe that doping monometallic Pt clusters even with a single Re atom increases their binding energy values and widens the bimetallic cluster highest occupied molecular orbital-lowest unoccupied molecular orbital gap. As catalysis occurs at elevated temperatures, we explore the concept of cluster fluxionality for Re-Pt minima in terms of the calculated isomer occupation probability, P(T). This allows us to quantify the abundance of GM and low-energy isomer configurations as a function of temperature. This is done at size 5 atoms due to the wide isomer observed variety. Our calculations indicate that for pure Re5, the P(T) of the GM configuration substantially decreases after 750 K. Especially, for Re4Pt1, the GM is the dominant structure up to nearly 700 K when the second-energy isomer becomes the stable one. Although no ordering changes are seen for Re3Pt2, Re2Pt3, and Re1Pt4, we do observe a structural transition-between the GM and the second isomer-for pure Pt5 above 1000 K. We expect this type of combined first-principles analysis to add to the overall, continuous understanding of the stability and energetics of ultrafine and highly-dispersed Re-Pt petroleum-reforming catalysts and the scarce available information on this particular bimetallic system.
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Affiliation(s)
- Luis E Gálvez-González
- Programa de Doctorado en Ciencias (Física), División de Ciencias Exactas y Naturales, Universidad de Sonora, Blvd. Luis Encinas y Rosales, Hermosillo, Sonora 83000, Mexico
| | - Alvaro Posada-Amarillas
- Departamento de Investigación en Física, Universidad de Sonora, Blvd. Luis Encinas y Rosales, Hermosillo, Sonora 83000, Mexico
| | - Lauro Oliver Paz-Borbón
- Instituto de Física, Universidad Nacional Autónoma de México, Ciudad de México 04510, Mexico
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7
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Haus MO, Meledin A, Leiting S, Louven Y, Roubicek NC, Moos S, Weidenthaler C, Weirich TE, Palkovits R. Correlating the Synthesis, Structure, and Catalytic Performance of Pt–Re/TiO2 for the Aqueous-Phase Hydrogenation of Carboxylic Acid Derivatives. ACS Catal 2021. [DOI: 10.1021/acscatal.0c05612] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Moritz O. Haus
- Lehrstuhl für Heterogene Katalyse und Technische Chemie, RWTH Aachen University, Worringerweg 2, DE-52074 Aachen, Germany
| | - Alexander Meledin
- Gemeinschaftslabor für Elektronenmikroskopie/Institut für Kristallographie, RWTH Aachen University, Ahornstraße 55, DE-52074 Aachen, Germany
- Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons (ER-C), Forschungszentrum Jülich GmbH, DE-52428 Jülich, Germany
| | - Sebastian Leiting
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, D-45470 Mülheim an der Ruhr, Germany
| | - Yannik Louven
- Lehrstuhl für Heterogene Katalyse und Technische Chemie, RWTH Aachen University, Worringerweg 2, DE-52074 Aachen, Germany
| | - Nico C. Roubicek
- Lehrstuhl für Heterogene Katalyse und Technische Chemie, RWTH Aachen University, Worringerweg 2, DE-52074 Aachen, Germany
| | - Sven Moos
- Lehrstuhl für Heterogene Katalyse und Technische Chemie, RWTH Aachen University, Worringerweg 2, DE-52074 Aachen, Germany
| | - Claudia Weidenthaler
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, D-45470 Mülheim an der Ruhr, Germany
| | - Thomas E. Weirich
- Gemeinschaftslabor für Elektronenmikroskopie/Institut für Kristallographie, RWTH Aachen University, Ahornstraße 55, DE-52074 Aachen, Germany
| | - Regina Palkovits
- Lehrstuhl für Heterogene Katalyse und Technische Chemie, RWTH Aachen University, Worringerweg 2, DE-52074 Aachen, Germany
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8
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Abstract
The water gas shift (WGS) is an equilibrium exothermic reaction, whose corresponding industrial process is normally carried out in two adiabatic stages, to overcome the thermodynamic and kinetic limitations. The high temperature stage makes use of iron/chromium-based catalysts, while the low temperature stage employs copper/zinc-based catalysts. Nevertheless, both these systems have several problems, mainly dealing with safety issues and process efficiency. Accordingly, in the last decade abundant researches have been focused on the study of alternative catalytic systems. The best performances have been obtained with noble metal-based catalysts, among which, platinum-based formulations showed a good compromise between performance and ease of preparation. These catalytic systems are extremely attractive, as they have numerous advantages, including the feasibility of intermediate temperature (250–400 °C) applications, the absence of pyrophoricity, and the high activity even at low loadings. The particle size plays a crucial role in determining their catalytic activity, enhancing the performance of the nanometric catalytic systems: the best activity and stability was reported for particle sizes < 1.7 nm. Moreover the optimal Pt loading seems to be located near 1 wt%, as well as the optimal Pt coverage was identified in 0.25 ML. Kinetics and mechanisms studies highlighted the low energy activation of Pt/Mo2C-based catalytic systems (Ea of 38 kJ·mol−1), the associative mechanism is the most encountered on the investigated studies. This review focuses on a selection of recent published articles, related to the preparation and use of unstructured platinum-based catalysts in water gas shift reaction, and is organized in five main sections: comparative studies, kinetics, reaction mechanisms, sour WGS and electrochemical promotion. Each section is divided in paragraphs, at the end of the section a summary and a summary table are provided.
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9
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Dong X, Jin B, Kong Z, Sun Y. Promotion effect of Re additive on the bifunctional Ni catalysts for methanation coupling with water gas shift of biogas: Insights from activation energy. Chin J Chem Eng 2020. [DOI: 10.1016/j.cjche.2020.03.016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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10
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Catalysis at Metal/Oxide Interfaces: Density Functional Theory and Microkinetic Modeling of Water Gas Shift at Pt/MgO Boundaries. Top Catal 2020. [DOI: 10.1007/s11244-020-01257-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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11
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Brandt AJ, Maddumapatabandi TD, Shakya DM, Xie K, Seuser GS, Farzandh S, Chen DA. Water-gas shift activity on Pt-Re surfaces and the role of the support. J Chem Phys 2019; 151:234714. [DOI: 10.1063/1.5128735] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Amy J. Brandt
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, USA
| | | | - Deependra M. Shakya
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, USA
| | - Kangmin Xie
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, USA
| | - Grant S. Seuser
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, USA
| | - Sharfa Farzandh
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, USA
| | - Donna A. Chen
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, USA
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12
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Gu L, Zeng Y, Feng Y, Jiang W, Ji W, Arandiyan H, Au C. How Do Structurally Distinct Au/α‐Fe
2
O
3
Interfaces Determine Surface OH/H
2
O reactivity, Intermediate Evolution, and Product Formation in Low‐temperature Water‐gas Shift Reaction? ChemCatChem 2019. [DOI: 10.1002/cctc.201900576] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Lingli Gu
- Key Laboratory of Mesoscopic ChemistryNanjing University Nanjing 210023 P. R. China
| | - Yiqiang Zeng
- Key Laboratory of Mesoscopic ChemistryNanjing University Nanjing 210023 P. R. China
| | - Yina Feng
- Key Laboratory of Mesoscopic ChemistryNanjing University Nanjing 210023 P. R. China
| | - Wu Jiang
- Key Laboratory of Mesoscopic ChemistryNanjing University Nanjing 210023 P. R. China
| | - Weijie Ji
- Key Laboratory of Mesoscopic ChemistryNanjing University Nanjing 210023 P. R. China
| | - Hamidreza Arandiyan
- Laboratory of Advanced Catalysis for SustainabilityThe University of Sydney NSW 2006 Australia
| | - Chak‐Tong Au
- Department of ChemistryHong Kong Baptist University Hong Kong
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13
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Zhan Y, Liu Y, Peng X, Zhao W, Zhang Y, Wang X, Au CT, Jiang L. Molecular-level understanding of reaction path optimization as a function of shape concerning the metal–support interaction effect of Co/CeO2 on water-gas shift catalysis. Catal Sci Technol 2019. [DOI: 10.1039/c9cy01260e] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
In this work, the active sites generated in hydrogen reduction and the reaction pathways for the water gas shift (WGS) reaction over Co/CeO2 catalysts were studied by in situ XAS and XPS coupled with DFT+U calculations.
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Affiliation(s)
- Yingying Zhan
- National Engineering Research Center of Chemical Fertilizer Catalyst
- Fuzhou University
- Fuzhou
- China
| | - Yi Liu
- National Engineering Research Center of Chemical Fertilizer Catalyst
- Fuzhou University
- Fuzhou
- China
| | - Xuanbei Peng
- National Engineering Research Center of Chemical Fertilizer Catalyst
- Fuzhou University
- Fuzhou
- China
| | - Weitao Zhao
- National Engineering Research Center of Chemical Fertilizer Catalyst
- Fuzhou University
- Fuzhou
- China
| | - Yongfan Zhang
- National Engineering Research Center of Chemical Fertilizer Catalyst
- Fuzhou University
- Fuzhou
- China
| | - Xiuyun Wang
- National Engineering Research Center of Chemical Fertilizer Catalyst
- Fuzhou University
- Fuzhou
- China
| | - Chak-tong Au
- National Engineering Research Center of Chemical Fertilizer Catalyst
- Fuzhou University
- Fuzhou
- China
| | - Lilong Jiang
- National Engineering Research Center of Chemical Fertilizer Catalyst
- Fuzhou University
- Fuzhou
- China
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14
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Plata JJ, Romero-Sarria F, Amaya Suárez J, Márquez AM, Laguna ÓH, Odriozola JA, Fdez Sanz J. Improving the activity of gold nanoparticles for the water-gas shift reaction using TiO 2-Y 2O 3: an example of catalyst design. Phys Chem Chem Phys 2018; 20:22076-22083. [PMID: 30112549 DOI: 10.1039/c8cp03706j] [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
In the last ten years, there has been an acceleration in the pace at which new catalysts for the water-gas shift reaction are designed and synthesized. Pt-based catalysts remain the best solution when only activity is considered. However, cost, operation temperature, and deactivation phenomena are important variables when these catalysts are scaled in industry. Here, a new catalyst, Au/TiO2-Y2O3, is presented as an alternative to the less selective Pt/oxide systems. Experimental and theoretical techniques are combined to design, synthesize, characterize and analyze the performance of this system. The mixed oxide demonstrates a synergistic effect, improving the activity of the catalyst not only at large-to-medium temperatures but also at low temperatures. This effect is related to the homogeneous dispersion of the vacancies that act both as nucleation centers for smaller and more active gold nanoparticles and as dissociation sites for water molecules. The calculated reaction path points to carboxyl formation as the rate-limiting step with an activation energy of 6.9 kcal mol-1, which is in quantitative agreement with experimental measurements and, to the best of our knowledge, it is the lowest activation energy reported for the water-gas shift reaction. This discovery demonstrates the importance of combining experimental and theoretical techniques to model and understand catalytic processes and opens the door to new improvements to reduce the operating temperature and the deactivation of the catalyst.
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Affiliation(s)
- Jose J Plata
- Departamento de Química Física, Universidad de Sevilla, Seville, Spain.
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15
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Naitabdi A, Boucly A, Rochet F, Fagiewicz R, Olivieri G, Bournel F, Benbalagh R, Sirotti F, Gallet JJ. CO oxidation activity of Pt, Zn and ZnPt nanocatalysts: a comparative study by in situ near-ambient pressure X-ray photoelectron spectroscopy. NANOSCALE 2018; 10:6566-6580. [PMID: 29577122 DOI: 10.1039/c7nr07981h] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The investigation of nanocatalysts under ambient pressure by X-ray photoelectron spectroscopy gives access to a wealth of information on their chemical state under reaction conditions. Considering the paradigmatic CO oxidation reaction, a strong synergistic effect on CO catalytic oxidation was recently observed on a partly dewetted ZnO(0001)/Pt(111) single crystal surface. In order to bridge the material gap, we have examined whether this inverse metal/oxide catalytic effect could be transposed on supported ZnPt nanocatalysts deposited on rutile TiO2(110). Synchrotron radiation near-ambient pressure X-ray photoelectron spectroscopy (NAP-XPS) operated at 1 mbar of O2 : CO mixture (4 : 1) was used at a temperature range between room temperature and 450 K. To tackle the complexity of the problem, we have also studied the catalytic activity of nanoparticles (NPs) of the same size, consisting of pure Pt and Zn nanoparticles (NPs), for which, moreover, NAP-XPS studies are a novelty. The comparative approach shows that the CO oxidation process is markedly different for the pure Pt and pure Zn NPs. For pure Pt NPs, CO poisoned the metallic surfaces at low temperature at the onset of CO2 evolution. In contrast, the pure Zn NPs first oxidize into ZnO, and trap carbonates at low temperature. Then they start to release CO2 in the gas phase, at a critical temperature, while continuously producing it. The pure Zn NPs are also immune to support encapsulation. The bimetallic nanoparticle borrows some of its characteristics from its two parent metals. In fact, the ZnPt NP, although produced by the sequential deposition of platinum and zinc, is platinum-terminated below the temperature onset of CO oxidation and poisoned by CO. Above the CO oxidation onset, the nanoparticle becomes Zn-rich with a ZnO shell. Pure Pt and ZnPt NPs present a very similar activity towards CO oxidation, in contrast with what is reported in a single crystal study. The present study demonstrates the effectiveness of NAP-XPS in the study of complex catalytic processes at work on nanocatalysts under near-ambient pressures, and highlights once more the difficulty of transposing single crystal surface observations to the case of nanoobjects.
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Affiliation(s)
- Ahmed Naitabdi
- Sorbonne Université, CNRS, Laboratoire de Chimie Physique Matière et Rayonnement, 4 place Jussieu, 75005 Paris, France.
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