Perovskite Oxygen Carriers for Hydrogen Production via Chemical Looping Steam Methane Reforming: A Review

The chemical looping steam methane reforming (CL-SMR) process is an efficient and low-carbon hydrogen production technology. It enables high-efficiency methane conversion and inherent CO2 separation through the cyclic utilization of oxygen carriers. Perovskite-materials are regarded as potential oxygen carriers due to their superior oxygen transport capabilities, tunable chemical compositions, and excellent high-temperature stability. This review summarizes recent advances in perovskite-based oxygen carriers, focusing on the effects of elemental doping and structural characteristics on key performance metrics, including methane conversion rate, CO selectivity, H2/CO ratio, and hydrogen yield. Based on existing research findings, we propose optimization strategies for improving the reaction performance of perovskite oxygen carriers in CL-SMR processes. Additionally, we outline future research directions, such as the design of high-efficiency oxygen carriers and in-depth exploration of reaction mechanisms. This work provides a comprehensive theoretical framework and research roadmap for advancing CL-SMR technology, while identifying potential pathways for developing efficient and stable perovskite-based oxygen carriers.