Mechanism investigation and catalyst screening of high-temperature reverse water gas shift reaction
Reverse water gas shift (RWGS) catalysis, a prominent technology for converting CO2 to CO, is emerging to meet the growing demand of global environment. However, the fundamental understanding of the reaction mechanism is hindered by the complex nature of the reaction. Herein, microkinetic modeling o...
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| Format: | Article |
| Language: | English |
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KeAi Communications Co. Ltd.
2020-12-01
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| Series: | Green Chemical Engineering |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S2666952820300169 |
| _version_ | 1797976368929046528 |
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| author | Yanying Qi Yi-An Zhu De Chen |
| author_facet | Yanying Qi Yi-An Zhu De Chen |
| author_sort | Yanying Qi |
| collection | DOAJ |
| description | Reverse water gas shift (RWGS) catalysis, a prominent technology for converting CO2 to CO, is emerging to meet the growing demand of global environment. However, the fundamental understanding of the reaction mechanism is hindered by the complex nature of the reaction. Herein, microkinetic modeling of RWGS on different metals (i.e., Co, Ru, Fe, Ni, Cu, Rh, Pd, and Pt) was performed based on the DFT results to provide the mechanistic insights and achieve the catalyst screening. Adsorption energies of the carbon-based species and the oxygen-based species can be correlated to the adsorption energy of carbon and oxygen, respectively. Moreover, oxygen adsorption energy is an excellent descriptor for the barrier of CO2 and CO direct dissociation and the difference in reaction barrier between CO2 (or CO) dissociation and hydrogenation. The reaction mechanism varies on various metals. Direct CO2 dissociation is the dominating route on Co, Fe, Ru, Rh, Cu, and Ni, while it competes with the COOH-mediated path on Pt and Pd surface. The eights metals can be divided into two groups based on the degree of rate control analysis for CO production, where CO–O bond cleavage is rate relevant on Pt, Pd, and Cu, and OH–H binding is rate-controlling on Co, Fe, Ru, Ni, and Rh. Both CO-direct dissociation and hydrogen-assisted route to CH4 contribute to the methane formation on Co, Fe, Pt, Pd, Ru, and Rh, despite the significant barrier difference between the two routes. Besides, the specific rate-relevant transition states and intermediates are suggested for methane formation, and thus, the selectivity can be tuned by adjusting the energy. The descriptor (C- and O- formation energy) based microkinetic modeling proposed that the activity trend is Rh~Ni > Pt~Pd > Cu > Co > Ru > Fe, where Fe, Co, Ru, and Ni tends to be oxidized. The predicted activity trend is well consistent with those obtained experimentally. The interpolation concept of adsorption energy was used to identify bimetallic materials for highly active catalysts for RWGS. |
| first_indexed | 2024-04-11T04:49:50Z |
| format | Article |
| id | doaj.art-4ef51e3d4fba433ebc898699a48679a4 |
| institution | Directory Open Access Journal |
| issn | 2666-9528 |
| language | English |
| last_indexed | 2024-04-11T04:49:50Z |
| publishDate | 2020-12-01 |
| publisher | KeAi Communications Co. Ltd. |
| record_format | Article |
| series | Green Chemical Engineering |
| spelling | doaj.art-4ef51e3d4fba433ebc898699a48679a42022-12-27T04:39:33ZengKeAi Communications Co. Ltd.Green Chemical Engineering2666-95282020-12-0112131139Mechanism investigation and catalyst screening of high-temperature reverse water gas shift reactionYanying Qi0Yi-An Zhu1De Chen2Norwegian University of Science and Technology, Sem Sælands Veg 4, Trondheim, 7049, NorwayUnited Chemical Reaction Engineering Research Institute (UNILAB), State Key Laboratory of Chemical Engineering, East China University of Science and Technology, Shanghai, 200237, ChinaNorwegian University of Science and Technology, Sem Sælands Veg 4, Trondheim, 7049, Norway; Corresponding author.Reverse water gas shift (RWGS) catalysis, a prominent technology for converting CO2 to CO, is emerging to meet the growing demand of global environment. However, the fundamental understanding of the reaction mechanism is hindered by the complex nature of the reaction. Herein, microkinetic modeling of RWGS on different metals (i.e., Co, Ru, Fe, Ni, Cu, Rh, Pd, and Pt) was performed based on the DFT results to provide the mechanistic insights and achieve the catalyst screening. Adsorption energies of the carbon-based species and the oxygen-based species can be correlated to the adsorption energy of carbon and oxygen, respectively. Moreover, oxygen adsorption energy is an excellent descriptor for the barrier of CO2 and CO direct dissociation and the difference in reaction barrier between CO2 (or CO) dissociation and hydrogenation. The reaction mechanism varies on various metals. Direct CO2 dissociation is the dominating route on Co, Fe, Ru, Rh, Cu, and Ni, while it competes with the COOH-mediated path on Pt and Pd surface. The eights metals can be divided into two groups based on the degree of rate control analysis for CO production, where CO–O bond cleavage is rate relevant on Pt, Pd, and Cu, and OH–H binding is rate-controlling on Co, Fe, Ru, Ni, and Rh. Both CO-direct dissociation and hydrogen-assisted route to CH4 contribute to the methane formation on Co, Fe, Pt, Pd, Ru, and Rh, despite the significant barrier difference between the two routes. Besides, the specific rate-relevant transition states and intermediates are suggested for methane formation, and thus, the selectivity can be tuned by adjusting the energy. The descriptor (C- and O- formation energy) based microkinetic modeling proposed that the activity trend is Rh~Ni > Pt~Pd > Cu > Co > Ru > Fe, where Fe, Co, Ru, and Ni tends to be oxidized. The predicted activity trend is well consistent with those obtained experimentally. The interpolation concept of adsorption energy was used to identify bimetallic materials for highly active catalysts for RWGS.http://www.sciencedirect.com/science/article/pii/S2666952820300169Reverse water gas shiftMicrokinetic modelingCatalyst screeningScaling relationship |
| spellingShingle | Yanying Qi Yi-An Zhu De Chen Mechanism investigation and catalyst screening of high-temperature reverse water gas shift reaction Green Chemical Engineering Reverse water gas shift Microkinetic modeling Catalyst screening Scaling relationship |
| title | Mechanism investigation and catalyst screening of high-temperature reverse water gas shift reaction |
| title_full | Mechanism investigation and catalyst screening of high-temperature reverse water gas shift reaction |
| title_fullStr | Mechanism investigation and catalyst screening of high-temperature reverse water gas shift reaction |
| title_full_unstemmed | Mechanism investigation and catalyst screening of high-temperature reverse water gas shift reaction |
| title_short | Mechanism investigation and catalyst screening of high-temperature reverse water gas shift reaction |
| title_sort | mechanism investigation and catalyst screening of high temperature reverse water gas shift reaction |
| topic | Reverse water gas shift Microkinetic modeling Catalyst screening Scaling relationship |
| url | http://www.sciencedirect.com/science/article/pii/S2666952820300169 |
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