Exploring the Influence of AlO x Polyhedra on Reactive Oxygen Sites and Oxidative Coupling of Methane (OCM) Reaction Performance of LaAlO 3 Perovskite

作者：Xiaomei Yu, Junwei Xu, Liang Guo, Jieqi Zhou, Rumeng Ouyang, Xiuzhong Fang, Jiating Shen, Xiang Wang · 发表于：Inorganic Chemistry · 年份：2025 · DOI：10.1021/acs.inorgchem.5c02724 · 被引用次数：5 · 研究领域：Catalytic Processes in Materials Science、Catalysis and Oxidation Reactions、Industrial Gas Emission Control

At present, there are still controversy viewpoints on the reactive oxygen sites in the OCM reaction on ABO 3 perovskites. Some researchers believe that electron-deficient chemisorbed oxygen species (O 2 –, O 2 2–, and O – ) contribute to C 2 product formation, and surface lattice oxygen (O 2– ) promotes the deep oxidation of methane, while others hold an opposite viewpoint. In addition, the influence of BO x polyhedra on the reactive sites and reaction performance has rarely been elucidated. Considering this, two types of LaAlO 3 perovskites, comprising different contents of surface and bulk coordinatively unsaturated sites (AlO 4 tetrahedra), were synthesized for the OCM reaction. Through a series of in situ and ex situ characterization techniques and combined with DFT calculations, a high oxygen vacancy concentration was revealed for the AlO 4 -rich LaAlO 3 perovskite, leading to an abundance of reactive oxygen and promoting oxygen mobility. The study identified monatomic surface lattice oxygen O 2– as the active sites for the deep oxidation of methane at low temperatures. The O 2 2– species generated by oxygen vacancies promotes the formation of C 2 products at high temperatures.