Mechanistic Insights for Dry Reforming of Methane on Cu/Ni Bimetallic Catalysts: DFT-Assisted Microkinetic Analysis for Coke Resistance
Density functional theory (DFT) calculations have been utilized to evaluate the complete reaction mechanism of methane dry reforming (DRM) over Ni<sub>2</sub>Cu (111) bimetallic catalyst. The detailed catalytic cycle on Ni<sub>2</sub>Cu (111) catalyst demonstrated superior co...
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MDPI AG
2020-09-01
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| Series: | Catalysts |
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| Online Access: | https://www.mdpi.com/2073-4344/10/9/1043 |
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| author | Ahmed Omran Sun Hee Yoon Murtaza Khan Minhaj Ghouri Anjaneyulu Chatla Nimir Elbashir |
| author_facet | Ahmed Omran Sun Hee Yoon Murtaza Khan Minhaj Ghouri Anjaneyulu Chatla Nimir Elbashir |
| author_sort | Ahmed Omran |
| collection | DOAJ |
| description | Density functional theory (DFT) calculations have been utilized to evaluate the complete reaction mechanism of methane dry reforming (DRM) over Ni<sub>2</sub>Cu (111) bimetallic catalyst. The detailed catalytic cycle on Ni<sub>2</sub>Cu (111) catalyst demonstrated superior coke resistance compared to pure Ni (111) and Ni<sub>2</sub>Fe (111) reported in the literature. Doping Cu in the Ni–Ni network enhanced the competitive CH oxidation by both atomic O and OH species with the latter having only 0.02 eV higher than the 1.06 eV energy barrier required for CH oxidation by atomic O. Among the C/CH oxidation pathways, C* + O* → CO (g) was the most favorable with an energy barrier of 0.72 eV. This was almost half of the energy barrier required for the rate-limiting step of CH decomposition (1.40 eV) and indicated enhanced coke deposition removal. Finally, we investigated the effect of temperature (800~1000 K) on the carbon deposition and elimination mechanism over Ni<sub>2</sub>Cu (111) catalyst. Under those realistic DRM conditions, the calculations showed a periodic cycle of simultaneous carbon deposition and elimination resulting in improved catalyst stability. |
| first_indexed | 2024-03-10T16:25:51Z |
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| id | doaj.art-d5c37b91f7014d0c85bebc3061e1d570 |
| institution | Directory Open Access Journal |
| issn | 2073-4344 |
| language | English |
| last_indexed | 2024-03-10T16:25:51Z |
| publishDate | 2020-09-01 |
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| record_format | Article |
| series | Catalysts |
| spelling | doaj.art-d5c37b91f7014d0c85bebc3061e1d5702023-11-20T13:18:06ZengMDPI AGCatalysts2073-43442020-09-01109104310.3390/catal10091043Mechanistic Insights for Dry Reforming of Methane on Cu/Ni Bimetallic Catalysts: DFT-Assisted Microkinetic Analysis for Coke ResistanceAhmed Omran0Sun Hee Yoon1Murtaza Khan2Minhaj Ghouri3Anjaneyulu Chatla4Nimir Elbashir5Chemical Engineering Program, Texas A&M University at Qatar, Doha 23874, QatarChemical Engineering Program, Texas A&M University at Qatar, Doha 23874, QatarChemical Engineering Program, Texas A&M University at Qatar, Doha 23874, QatarChemical Engineering Program, Texas A&M University at Qatar, Doha 23874, QatarChemical Engineering Program, Texas A&M University at Qatar, Doha 23874, QatarChemical Engineering Program, Texas A&M University at Qatar, Doha 23874, QatarDensity functional theory (DFT) calculations have been utilized to evaluate the complete reaction mechanism of methane dry reforming (DRM) over Ni<sub>2</sub>Cu (111) bimetallic catalyst. The detailed catalytic cycle on Ni<sub>2</sub>Cu (111) catalyst demonstrated superior coke resistance compared to pure Ni (111) and Ni<sub>2</sub>Fe (111) reported in the literature. Doping Cu in the Ni–Ni network enhanced the competitive CH oxidation by both atomic O and OH species with the latter having only 0.02 eV higher than the 1.06 eV energy barrier required for CH oxidation by atomic O. Among the C/CH oxidation pathways, C* + O* → CO (g) was the most favorable with an energy barrier of 0.72 eV. This was almost half of the energy barrier required for the rate-limiting step of CH decomposition (1.40 eV) and indicated enhanced coke deposition removal. Finally, we investigated the effect of temperature (800~1000 K) on the carbon deposition and elimination mechanism over Ni<sub>2</sub>Cu (111) catalyst. Under those realistic DRM conditions, the calculations showed a periodic cycle of simultaneous carbon deposition and elimination resulting in improved catalyst stability.https://www.mdpi.com/2073-4344/10/9/1043density functional theory (DFT)dry reforming of methane (DRM)Ni<sub>2</sub>Cu (111)bimetallic catalystcoke resistancecatalyst deactivation |
| spellingShingle | Ahmed Omran Sun Hee Yoon Murtaza Khan Minhaj Ghouri Anjaneyulu Chatla Nimir Elbashir Mechanistic Insights for Dry Reforming of Methane on Cu/Ni Bimetallic Catalysts: DFT-Assisted Microkinetic Analysis for Coke Resistance Catalysts density functional theory (DFT) dry reforming of methane (DRM) Ni<sub>2</sub>Cu (111) bimetallic catalyst coke resistance catalyst deactivation |
| title | Mechanistic Insights for Dry Reforming of Methane on Cu/Ni Bimetallic Catalysts: DFT-Assisted Microkinetic Analysis for Coke Resistance |
| title_full | Mechanistic Insights for Dry Reforming of Methane on Cu/Ni Bimetallic Catalysts: DFT-Assisted Microkinetic Analysis for Coke Resistance |
| title_fullStr | Mechanistic Insights for Dry Reforming of Methane on Cu/Ni Bimetallic Catalysts: DFT-Assisted Microkinetic Analysis for Coke Resistance |
| title_full_unstemmed | Mechanistic Insights for Dry Reforming of Methane on Cu/Ni Bimetallic Catalysts: DFT-Assisted Microkinetic Analysis for Coke Resistance |
| title_short | Mechanistic Insights for Dry Reforming of Methane on Cu/Ni Bimetallic Catalysts: DFT-Assisted Microkinetic Analysis for Coke Resistance |
| title_sort | mechanistic insights for dry reforming of methane on cu ni bimetallic catalysts dft assisted microkinetic analysis for coke resistance |
| topic | density functional theory (DFT) dry reforming of methane (DRM) Ni<sub>2</sub>Cu (111) bimetallic catalyst coke resistance catalyst deactivation |
| url | https://www.mdpi.com/2073-4344/10/9/1043 |
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