文献类型：期刊文献

英文题名：Insights into Flagg Iron-Carbide-Catalyzed Fischer-Tropsch Synthesis: Suppression of CH4 Formation and Enhancement of C-C Coupling on χ-Fe5C2 (510)

作者：Thanh Hai Pham[1];Qi, Yanying[2];Yang, Jia[3];Duan, Xuezhi[1];Qian, Gang[1];Zhou, Xinggui[1];Chen, De[2];Yuan, Weikang[1]

机构：[1]E China Univ Sci & Technol, State Key Lab Chem Engn, Shanghai 200237, Peoples R China;[2]Norwegian Univ Sci & Technol, Dept Chem Engn, N-7491 Trondheim, Norway;[3]SINTEF Mat & Chem, N-7463 Trondheim, Norway

年份：2015

卷号：5

期号：4

起止页码：2203

外文期刊名：ACS CATALYSIS

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000352464400022)】；

基金：This work is financially supported by the Natural Science Foundation of China (21306046) and the 111 Project of Ministry of Education of China (B08021).

语种：英文

外文关键词：chi-Fe5C2 catalyst; Fischer-Tropsch synthesis selectivity; CH4 formation; C-C coupling; carbide mechanism

摘要：Probing the product selectivity of Fischer-Tropsch catalysts is of prime scientific and industrial importance-with the aim to upgrade products and meet various end-use applications. In this work, the mechanisms for CH4 formation and C-1-C-1 coupling on a thermodynamically stable, terraced-like chi-Fe5C(2) (510) surface were studied by DFT calculations. It was found that this surface exhibits high effective barriers of CH4 formation for the three cases (i.e., 3.66, 2.81, and 2.39 eV), indicating the unfavorable occurrence of CH4 formation under FTS conditions. The C + CH and CH + CH are the most likely coupling pathways, which follow the carbide mechanism. Subsequently, the effective barrier difference between CH4 formation and C1-C1 coupling was used as a descriptor to quantify FTS selectivity. A comparison of the selectivity between this surface and the reported FTS catalysts surfaces was discussed in detail. More interestingly, this surface shows unexpectedly high C2+ selectivity. This indicates that manipulating the crystal facet of chi-Fe5C2 catalyst can effectively tune the FTS selectivity, which will open a new avenue for highly selective Fe-based FTS catalysts.