文献类型：期刊文献

英文题名：Effects of Oxygen Mobility in La-Fe-Based Perovskites on the Catalytic Activity and Selectivity of Methane Oxidation

作者：Chang, Hui[1];Bjorgum, Erlend[2];Mihai, Oana[2];Yang, Jie[1];Lein, Hilde Lea[3];Grande, Tor[3];Raaen, Steinar[4];Zhu, Yi-An[1];Holmen, Anders[2];Chen, De[2]

机构：[1]East China Univ Sci & Technol, Sch Chem Engn, United Chem React Engn Res Inst UNILAB, State Key Lab Chem Engn, Shanghai 200237, Peoples R China;[2]Norwegian Univ Sci & Technol, Dept Chem Engn, NO-7491 Trondheim, Norway;[3]Norwegian Univ Sci & Technol, Dept Mat Sci & Engn, N-9491 Trondheim, Norway;[4]Norwegian Univ Sci & Technol, Dept Phys, N-9491 Trondheim, Norway

年份：2020

卷号：10

期号：6

起止页码：3707

外文期刊名：ACS CATALYSIS

收录：;EI(收录号：20201508404472);WOS:【SCI-EXPANDED(收录号:WOS:000526394500022)】；

基金：The financial support from the Norwegian Research Council through the KOSK program, the Norwegian University of Science and Technology (NTNU), the Natural Science Foundation of China (21473053, 91645122, and U1663221), and the Fundamental Research Funds for the Central Universities (222201718003) is greatly acknowledged. The computational time is provided by the Notur project (NN4685k).

语种：英文

外文关键词：perovskite; surface composition; methane partial oxidation; methane total combustion; chemical looping; density functional theory

摘要：The mechanism and structure requirements of selective and total oxidation of methane in a chemical looping process are both experimentally and theoretically examined on La1-xSrxFeO3-delta (x = 0, 0.2, and 0.5) and La0.5Sr0.5Fe1-xCoxO3-delta (x = 0.5 and 1) perovskites. The oxygen mobility in the perovskites described by the formation energy of oxygen vacancy is found to have a pronounced effect on the catalytic activity and selectivity. In particular, the selectivity is controlled largely by the surface oxygen concentration or the oxygen vacancy concentration on perovskites, which depends strongly on the bulk oxygen concentration and the relative rate of the lattice oxygen diffusion with respect to the surface reaction. The substitution of Sr for La at the A site and the substitution of Co for Fe at the B site of the ABO(3) perovskites dramatically increase the oxygen mobility. A higher oxygen diffusion rate, and hence enrichment of oxygen on the surface, would improve the catalyst selectivity toward total oxidation.