文献类型：期刊文献

英文题名：Mechanistic aspects of facet-dependent CH4/C2+ selectivity over a χ-Fe5C2 Fischer-Tropsch catalyst

作者：Pham, Thanh Hai[1,2];Cao, Junbo[1];Song, Nan[1];Cao, Yueqiang[1];Chen, Bingxu[1];Qian, Gang[1];Zhou, Xinggui[1];Chen, De[3];Duan, Xuezhi[1]

机构：[1]East China Univ Sci & Technol, State Key Lab Chem Engn, 130 Meilong Rd, Shanghai 200237, Peoples R China;[2]Vietnam Inst Trop Technol & Environm Protect, 57A Truong Quoc Dung, Ho Chi Minh, Vietnam;[3]Norwegian Univ Sci & Technol, Dept Chem Engn, N-7491 Trondheim, Norway

年份：2022

卷号：7

期号：3

起止页码：449

外文期刊名：GREEN ENERGY & ENVIRONMENT

收录：;EI(收录号：20212310451827);WOS:【SCI-EXPANDED(收录号:WOS:000780126200006)】；

基金：This work was financially supported by the Natural Science Foundation of China (21922803 and 21776077), the Program for the Professor of Special Appointment (Eastern Scholar) at Shanghai Institutions of Higher Learning, the State Key Lab-oratory of Organic-Inorganic Composites (oic-201801007), and the Open Project of State Key Laboratory of Chemical Engi-neering (SKLChe-15C03).

语种：英文

外文关键词：Fischer-Tropsch synthesis; chi-Fe5C2; Structural sensitivity; CH4 selectivity

摘要：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 chi-Fe5C2 surfaces and established the kinetic equations to compare the rates of CH4 formation and C-1+C-1 coupling reactions and determine the CH4/C2+ selectivity. The results show that the geometry of the chi-Fe5C2 surfaces has little effect on the formation rate of CH4; however, the C-1+C-1 coupling reactions are significantly affected by the surface geometry. The C-1+C-1 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 Bronsted-Evans-Polanyi (BEP) relationship between the effective barrier difference for CH4 formation and C-1+C-1 coupling (Delta E-eff) and the adsorption energy of C+4H (Delta E-C+(4H)) on chi-Fe5C2 surfaces. Delta EC+4H can be used as a descriptor for CH4/C2+ selectivity on different surfaces of chi-Fe5C2. (C) 2020 Institute of Process Engineering, Chinese Academy of Sciences. Publishing services by Elsevier B.V. on behalf of KeAi Communications Co., Ltd.