Photocatalytic CO₂ conversion: What can we learn from conventional CO_x hydrogenation?

Solar-driven reduction of CO₂ into fuels/feedstocks is a promising strategy for addressing energy and CO₂ emission issues. Despite great research efforts, it still remains a grand challenge to achieve efficient and highly selective reduction of CO₂ owing to the large bond energy of CO₂ and the diversity of reduction products. In addition to the control of light harvesting and charge transfer like photocatalytic water splitting, the design of catalytically active sites is highly important to promote CO₂ reduction activity and selectivity (e.g., C-C coupling). In fact, we can learn a lot from conventional CO₂ hydrogenation and syngas conversion in terms of active site design. In this article, we demonstrate how to design catalytically active sites for efficient and highly selective photocatalytic reduction of CO₂ by sorting out the rules from the existing research on conventional CO_x hydrogenation, with a focus on enhancing C[double bond, length as m-dash]O activation and C-C coupling to form value-added products. This article aims to highlight the challenges in the field of photocatalytic CO₂ conversion and the connection of photocatalysis with conventional catalytic systems, providing the readers the opportunities to join the research.