文献类型：期刊文献

英文题名：Effects of surface oxygen vacancy on the kinetics of LaFeO3-catalyzed selective ammonia oxidation

作者：Zhou, Ze-Yi[1];Niu, Zi-Hua[1];Chen, Meng-Qin[1];Lei, Ming[1];Zhou, Xing-Gui[1];Chen, De[1,2];Zhu, Yi-An[1]

机构：[1]East China Univ Sci & Technol, Sch Chem Engn, State Key Lab Green Chem Engn & Ind Catalysis, UNILAB, Shanghai 200237, Peoples R China;[2]Norwegian Univ Sci & Technol, Dept Chem Engn, N-7491 Trondheim, Norway

年份：2026

卷号：334

外文期刊名：CHEMICAL ENGINEERING SCIENCE

收录：;EI(收录号：20262320829013);WOS:【SCI-EXPANDED(收录号:WOS:001786022900001)】；

基金：This work is supported by the National Natural Science Foundation of China (22573030), the National Key Research and Development Program of China (2024YFA1509901), and the research council of Norway through the innovation project for the industrial sector (340988, with Yara International).

语种：英文

外文关键词：Selective ammonia oxidation; Surface oxygen vacancy effect; Microkinetic modeling; Degree of rate control

摘要：Ammonia oxidation represents a fundamental process in the inorganic chemical industry, which produces nitric oxides as raw materials for the manufacture of nitric acid and fertilizers. In this work, the selective ammonia oxidation reaction on LaFeO3 are found to take place via two distinct regimes governed by different active ensembles, namely, the Fe-O5 ensemble over the defect-free LaFeO3 surface and the Fe-O4(Vo) ensemble over the defective surface. The electronic structures of these surfaces are studied, identifying the O ions lying above the surface as the main active oxygen site. The selective ammonia oxidation reaction on the LaFeO3 surface proceeds via the Mars van Krevelen mechanism. Microkinetic modeling results demonstrate that NO and H2O are the main products on the defect-free surface, while N2 and H2 become the main products on the defective surface as the surface oxygen vacancy concentration increases. Flux analysis of selective ammonia oxidation on the defect-free and defective LaFeO3 surfaces is then carried out to identify the dominant reaction pathway. Further sensitivity analysis based on the degree of rate control and selectivity control is also performed, proposing that the surface oxygen is the key intermediate that characterizes the ease with which oxygen vacancies can be formed and the formation of H2O and H2 may also affect the kinetics. All these findings provide solid foundations for the rational design of high-performance perovskite-type catalysts for the selective ammonia oxidation reaction. Topical Heading:Reaction Engineering, Kinetics and Catalysis.