Photothermal CO2 Hydrogenation to Multicarbon Products: Mechanisms, Catalyst Design, and Scale Demonstration

Abstract Photothermal CO 2 hydrogenation to multicarbon products presents a promising route to mitigate global climate change while simultaneously generating valuable C 2+ products for industrial use. However, realizing high activity and selectivity toward multicarbon products remains a significant challenge, primarily due to the intricate nature of reactant activation and the inherently sluggish kinetics of C−C coupling. This review elucidates the fundamental principles of photothermal catalysis, with a particular focus on the synergistic interplay between light and thermal energy. In addition, the activation pathways of CO 2 to C 1 intermediates and the subsequent mechanisms of C−C bond formation leading to multicarbon products are systematically examined. On this basis, catalyst design and modification strategies are categorized to enhance reactant activation and facilitate efficient C−C coupling. Furthermore, recent progress in pilot-scale demonstrations is highlighted to showcase the potential for scalable and sustainable CO 2 hydrogenation technologies. By addressing the current challenges and outlining future research directions, this review aims to accelerate the development of efficient photothermal processes for CO 2 valorization.