文献类型：期刊文献

中文题名：Effects of zinc on χ-Fe_(5)C_(2) for carbon dioxide hydrogenation to olefins:Insights from experimental and density function theory calculations

作者：Xianglin Liu[1,2];Minjie Xu[1];Chenxi Cao[1,3];Zixu Yang[1];Jing Xu[1]

机构：[1]State Key Laboratory of Chemical Engineering,East China University of Science and Technology,Shanghai 200237,China;[2]Maoming Branch R&D Institute,SINOPEC,Maoming 525000,China;[3]Key Laboratory of Smart Manufacturing in Energy Chemical Process,Ministry of Education,East China University of Science and Technology,Shanghai 200237,China

年份：2023

卷号：54

期号：2

起止页码：206

中文期刊名：Chinese Journal of Chemical Engineering

外文期刊名：中国化学工程学报（英文版）

收录：CSTPCD;;Scopus;CSCD:【CSCD2023_2024】；PubMed;

基金：the funding support from Shanghai Sailing Program (19YF1411000);National Natural Science Foundation of China (21878080, 21808058);Ningxia Science Foundation (2019AAC03282)。

语种：英文

中文关键词：Reaction engineering;χ-Fe_(5)C_(2);Zn promoter;Carbon dioxide;Hydrogenation;Density function theory

摘要：Production of light olefins from CO_(2), the primary greenhouse gases, is of great importance to mitigate the adverse effects of CO_(2) emission on environment and to supply the value-added products from nonpetroleum resource. However, development of robust catalyst with controllable selectivity and stability remains a challenge. Herein, we report that Zn-promoted Fe catalyst can boost the stable and selective production of light olefins from CO_(2). Specifically, the Zn-promoted Fe exhibits a highly stable activity and olefin selectivity over 200 h time-on-stream compared to the unpromoted Fe catalyst, primarily owing to the preservation of active χ-Fe_(5)C_(2) phase. Structural characterizations of the spent catalysts suggest that Zn substantially regulates the content of iron carbide on the surface and suppresses the reoxidation of bulk iron carbide during the reaction. DFT calculations confirm that adsorption of surface carbon atoms and graphene-like carbonaceous species are not thermochemically favored on Zn-promoted Fe catalyst. Carbon deposition by CAC coupling reactions of two surface carbon atoms and dehydrogenation of CH intermediate are also inhibited. Furthermore, the effects of Zn on antioxidation of iron carbide were also investigated. Zn favored the hydrogenation of surface adsorbed oxygen atoms to H_(2)O and the desorption of H_(2)O, which reduces the possibility of surface carbide being oxidized by the chemisorbed oxygen.