Harnessing light and heat: Composite metal oxide catalysts for sustainable CO 2 hydrogenation to C 1 products

Abstract 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, 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.