Mechanistic aspects of facet-dependent CH4/C2+ selectivity over a χ-Fe5C2 Fischer–Tropsch catalyst
Structure–performance relationship is a complex issue in iron-catalyzed Fischer–Tropsch synthesis, and it is not easy to elucidate it by experimental investigations. First-principle calculation is a powerful method for explaining experimental results and guiding catalyst design. In this study, we in...
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| Format: | Article |
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KeAi Communications Co., Ltd.
2022-06-01
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| Series: | Green Energy & Environment |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S2468025720301722 |
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| author | Thanh Hai Pham Junbo Cao Nan Song Yueqiang Cao Bingxu Chen Gang Qian Xinggui Zhou De Chen Xuezhi Duan |
| author_facet | Thanh Hai Pham Junbo Cao Nan Song Yueqiang Cao Bingxu Chen Gang Qian Xinggui Zhou De Chen Xuezhi Duan |
| author_sort | Thanh Hai Pham |
| collection | DOAJ |
| description | Structure–performance relationship is a complex issue in iron-catalyzed Fischer–Tropsch synthesis, and it is not easy to elucidate it by experimental investigations. First-principle calculation is a powerful method for explaining experimental results and guiding catalyst design. In this study, we investigated the reaction mechanisms of CH4 formation and C–C coupling on four χ-Fe5C2 surfaces and established the kinetic equations to compare the rates of CH4 formation and C1+C1 coupling reactions and determine the CH4/C2+ selectivity. The results show that the geometry of the χ-Fe5C2 surfaces has little effect on the formation rate of CH4; however, the C1+C1 coupling reactions are significantly affected by the surface geometry. The C1+C1 coupling reaction rates on the terraced-like (510) and (021) surfaces are much higher than those on the stepped-like (001) and (100) surfaces. Based on these results, we established a Brønsted–Evans–Polanyi (BEP) relationship between the effective barrier difference for CH4 formation and C1+C1 coupling (ΔEeff) and the adsorption energy of C+4H (ΔEC+4H) on χ-Fe5C2 surfaces. ΔEC+4H can be used as a descriptor for CH4/C2+ selectivity on different surfaces of χ-Fe5C2. |
| first_indexed | 2024-04-13T15:32:43Z |
| format | Article |
| id | doaj.art-f317ee59769a48d5b2ae098d285bea99 |
| institution | Directory Open Access Journal |
| issn | 2468-0257 |
| language | English |
| last_indexed | 2024-04-13T15:32:43Z |
| publishDate | 2022-06-01 |
| publisher | KeAi Communications Co., Ltd. |
| record_format | Article |
| series | Green Energy & Environment |
| spelling | doaj.art-f317ee59769a48d5b2ae098d285bea992022-12-22T02:41:21ZengKeAi Communications Co., Ltd.Green Energy & Environment2468-02572022-06-0173449456Mechanistic aspects of facet-dependent CH4/C2+ selectivity over a χ-Fe5C2 Fischer–Tropsch catalystThanh Hai Pham0Junbo Cao1Nan Song2Yueqiang Cao3Bingxu Chen4Gang Qian5Xinggui Zhou6De Chen7Xuezhi Duan8State Key Laboratory of Chemical Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, China; Vietnam Institute for Tropical Technology and Environmental Protection, 57A Truong Quoc Dung, Ho Chi Minh, Viet NamState Key Laboratory of Chemical Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, ChinaState Key Laboratory of Chemical Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, ChinaState Key Laboratory of Chemical Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, China; Corresponding authors.State Key Laboratory of Chemical Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, ChinaState Key Laboratory of Chemical Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, ChinaState Key Laboratory of Chemical Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, ChinaDepartment of Chemical Engineering, Norwegian University of Science and Technology, N-7491, Trondheim, NorwayState Key Laboratory of Chemical Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, China; Corresponding authors.Structure–performance relationship is a complex issue in iron-catalyzed Fischer–Tropsch synthesis, and it is not easy to elucidate it by experimental investigations. First-principle calculation is a powerful method for explaining experimental results and guiding catalyst design. In this study, we investigated the reaction mechanisms of CH4 formation and C–C coupling on four χ-Fe5C2 surfaces and established the kinetic equations to compare the rates of CH4 formation and C1+C1 coupling reactions and determine the CH4/C2+ selectivity. The results show that the geometry of the χ-Fe5C2 surfaces has little effect on the formation rate of CH4; however, the C1+C1 coupling reactions are significantly affected by the surface geometry. The C1+C1 coupling reaction rates on the terraced-like (510) and (021) surfaces are much higher than those on the stepped-like (001) and (100) surfaces. Based on these results, we established a Brønsted–Evans–Polanyi (BEP) relationship between the effective barrier difference for CH4 formation and C1+C1 coupling (ΔEeff) and the adsorption energy of C+4H (ΔEC+4H) on χ-Fe5C2 surfaces. ΔEC+4H can be used as a descriptor for CH4/C2+ selectivity on different surfaces of χ-Fe5C2.http://www.sciencedirect.com/science/article/pii/S2468025720301722Fischer–Tropsch synthesisχ-Fe5C2Structural sensitivityCH4 selectivity |
| spellingShingle | Thanh Hai Pham Junbo Cao Nan Song Yueqiang Cao Bingxu Chen Gang Qian Xinggui Zhou De Chen Xuezhi Duan Mechanistic aspects of facet-dependent CH4/C2+ selectivity over a χ-Fe5C2 Fischer–Tropsch catalyst Green Energy & Environment Fischer–Tropsch synthesis χ-Fe5C2 Structural sensitivity CH4 selectivity |
| title | Mechanistic aspects of facet-dependent CH4/C2+ selectivity over a χ-Fe5C2 Fischer–Tropsch catalyst |
| title_full | Mechanistic aspects of facet-dependent CH4/C2+ selectivity over a χ-Fe5C2 Fischer–Tropsch catalyst |
| title_fullStr | Mechanistic aspects of facet-dependent CH4/C2+ selectivity over a χ-Fe5C2 Fischer–Tropsch catalyst |
| title_full_unstemmed | Mechanistic aspects of facet-dependent CH4/C2+ selectivity over a χ-Fe5C2 Fischer–Tropsch catalyst |
| title_short | Mechanistic aspects of facet-dependent CH4/C2+ selectivity over a χ-Fe5C2 Fischer–Tropsch catalyst |
| title_sort | mechanistic aspects of facet dependent ch4 c2 selectivity over a χ fe5c2 fischer tropsch catalyst |
| topic | Fischer–Tropsch synthesis χ-Fe5C2 Structural sensitivity CH4 selectivity |
| url | http://www.sciencedirect.com/science/article/pii/S2468025720301722 |
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