Recent Advances of Oxygen Carriers for Chemical Looping Reforming of Methane

This review discussed recent advances of oxygen carriers (OCs) for chemical looping reforming (CLR) of CH4 which aims to generate high‐quality syngas, an important chemical intermediate for the synthesis of chemicals and fuels. We firstly introduced CLR and that combined with CO2 and H2O splitting as well as clarified their advantages over conventional reforming processes. Then we reviewed the latest advances of metal‐based OCs, composite OCs including perovskites and hexaaluminates, and catalytic OCs, namely oxygen‐containing materials with catalytically metal sites, during the past five years. Specific discussion focused on the influence of composition, surface, and bulk structure of these OCs on conversion, selectivity, and lattice oxygen reactivity to summarize design and optimization strategies of the tailored OCs. Finally, a brief summary and an outlook on some of the scientific challenges and suggestions for future investigations on the development of outstanding OCs for CLR of CH4 are given. Chemical looping reforming (CLR) of CH4 is a promising approach to produce syngas with high efficiency, safety, and environmental friendliness. This Review discusses the latest advances in the development of oxygen carriers (OCs) which are the key of the CLR process, with a focus on the performance and its relationship to structure. We summarize the general strategy to optimize and design OCs and discuss the perspectives and challenges of OCs for CLR of CH4.