Recent advances in supported metal catalysts for CO2 methanation: mechanisms, materials design, and the promise of perovskite-based supports

• Reviewed recent advances in supported metal catalysts for CO 2 methanation. • Compared Ru, Rh, Pd, Ni, and Co catalysts with detailed mechanism discussion. • Evaluated effects of oxide, carbon, and perovskite supports on catalyst performance. • Highlighted benefits of perovskites: redox flexibility, vacancies, and metal exsolution. • Identified key challenges and future directions for scalable CO 2 methanation. The mitigation of climate change demands transformative approaches to reduce carbon emissions and utilizing carbon dioxide (CO 2 ) as a valuable feedstock. Among various CO 2 utilization pathways, the catalytic hydrogenation of CO 2 to methane (CH 4 ) stands out as a promising strategy for enabling carbon recycling and renewable fuel production. Despite its thermodynamic favorability, the process is challenged by high activation energy and the necessity for efficient, selective, and durable catalysts. Supported metal catalysts ranging from noble metals (e.g., Ru, Rh, Pd) to non-noble alternatives (e.g., Ni, Co) have shown significant potential in overcoming these barriers. This review comprehensively examines recent progress in CO 2 methanation catalysts, highlighting reaction mechanisms, the interplay between active metals and supports, and the influence of structural and electronic properties on catalytic performance. Particular attention is given to emerging perovskite-based supports, which exhibit tunable redox behavior, oxygen vacancy generation, and in situ metal exsolution, offering new directions for catalyst design. Current challenges and future strategies for improving catalyst stability, scalability, and mechanistic understanding are also discussed, with the aim of guiding the rational development of next-generation catalysts to meet the demands of industrial deployment and carbon neutrality objectives.