化学链催化甲烷氧化反应研究进展

Advances in chemical looping methane oxidation

甲烷作为天然气的主要组成成分,其有效利用具有重要的现实意义。本文首先介绍了甲烷转化工艺,系统地比较了传统甲烷氧化与化学链催化甲烷氧化工艺,提出化学链重整技术作为一种应用于甲烷氧化反应的新技术,提供了一个多功能平台,以清洁及有效的方式转换燃料。然后,介绍了应用于此技术的催化剂研究现状,重点关注具有高储氧性能、催化性能以及低合成成本特点的钙钛矿复合氧化物,特别综述了利用机器学习方法高通量筛选钙钛矿氧化物催化剂的理论计算工作。最后,系统讨论了钙钛矿氧化物对化学链催化甲烷氧化反应性能的影响规律,依据实验和密度泛函理论计算研究结果,对催化剂颗粒尺寸、金属离子价态、氧空穴形成能以及氧浓度同催化性能之间的关系进行了分析,提出钙钛矿氧化物催化甲烷氧化反应的关键影响因素,为钙钛矿氧化物催化剂的筛选提供理论支撑。

Methane is the main constituent of natural gas and its utilization is of curial importance.This work first introduces methane conversion processes and then makes a comparison between traditional methane oxidation and chemical looping methane oxidation processes which builds a versatile platform to convert fuels in a clean and efficient manner.Then,the main advances in the recent development of the catalysts for chemical looping methane oxidation are presented,among which perovskites are focused because of their high oxygen storage,reactivity,and low synthesis cost.Moreover,the machine learning method for high-throughput screening of perovskites is briefly introduced.Furthermore,the way by which perovskites catalyze chemical looping methane oxidation as well as the factors that determine the reactivity and selectivity,including particle size,metal valence,oxygen vacancy formation energy,and oxygen concentration,are systematically discussed,which provides a foundation for the screening of perovskite catalysts for methane oxidation.