Harnessing light and heat: Composite metal oxide catalysts for sustainable CO ₂ hydrogenation to C1 products

With the escalating climate crisis caused by uncontrolled CO₂ emissions, technological breakthroughs in CO₂ capture and utilization have become imperative. Among these, photothermal catalysis, which utilizes full-spectrum to deliver necessary thermal input alongside photogenerated charge carriers, stands out by overcoming the high-temperature requirements of thermal catalysis and enhancing reaction kinetics. Composite metal oxides (CMOs) emerge as pivotal catalysts for photothermal CO₂ hydrogenation toward valuable C1 products, leveraging tunable electronic structures and abundant oxygen vacancies that facilitate CO₂ activation and H₂ dissociation, while multi-phase interfaces promote synergistic electron transfer that refines selective pathways. Despite the rapid development of CMOs in photothermal CO₂ hydrogenation in recent years, the research remains fragmented and lacks a systematic consolidation. This review delineates synthesis strategies for composite metal oxide catalysts and categorically examines recent advancements in application for converting CO₂ into valuable C1 products, and elaborates on the mechanisms of reverse water-gas shift (RWGS), methanation, and methanol synthesis pathways. Finally, we consolidate these insights to look ahead, addressing persistent challenges and strategic opportunities.