文献类型：期刊文献

英文题名：On the ensemble requirement of fully selective chemical looping methane partial oxidation over La-Fe-based perovskites

作者：Yang, Jie[1];Bjorgum, Erlend[2,3];Chang, Hui[1];Zhu, Ka-Ke[1];Sui, Zhi-Jun[1];Zhou, Xing-Gui[1];Holmen, Anders[2];Zhu, Yi-An[1];Chen, De[2]

机构：[1]East China Univ Sci & Technol, Sch Chem Engn, State Key Lab Chem Engn, UNILAB, Shanghai 200237, Peoples R China;[2]Norwegian Univ Sci & Technol, Dept Chem Engn, NO-91 Trondheim, Norway;[3]Equinor, N-5954 Mongstad, Monstad, Norway

年份：2022

卷号：301

外文期刊名：APPLIED CATALYSIS B-ENVIRONMENT AND ENERGY

收录：;EI(收录号：20214111017228);WOS:【SCI-EXPANDED(收录号:WOS:000707873600003)】；

基金：This work is supported by the Natural Science Foundation of China (21473053, 22073027, and 22178111) , the Natural Science Foundation of Shanghai (20ZR1415800) , the Fundamental Research Funds for the Central Universities (222201718003) , and the Norwegian Research Council through the KOSK program. The computational time provided by the Notur project is highly acknowledged.

语种：英文

外文关键词：Perovskite; Methane partial oxidation; Surface oxygen vacancy; Methane total combustion

摘要：The dynamic nature of active sites on La-Fe-based perovskites in chemical looping methane oxidation has been studied. According to experimental observations, the reduction of the oxygen carrier is divided into three stages occurring at different active ensembles where the Fe cations are in different coordination environments. The Mars van Krevelen mechanism formulated by microkinetic analysis describes well the effect of oxygen vacancy on the catalytic performance of LaFeO3. CO2 is not produced by CO oxidation but rather is a primary product of methane oxidation, and the presence of surface oxygen vacancies would dramatically increase the overall energy barrier for total combustion, thus decreasing the selectivity toward CO2. Hence, the Fe coordination environment (and hence the oxygen vacancy concentration) is the key parameter governing the catalyst selectivity, in the sense that methane oxidation can vary from total combustion on the O-rich surface to fully selective partial oxidation on the O-deficient surface.