Embedding Metallosalen Active Sites in Zr‐MOF for Enhanced Selective Syngas Production from CO ₂ Photoreduction

Abstract

Abstract Selective photocatalytic CO 2 reduction to product syngas remains a great challenge. Herein, we proposed a novel strategy by integration of metallosalen (M‐Salen) active sites and Zr‐MOF, to promote the selective production of syngas through photocatalytic CO 2 and H 2 O reduction. A series of M‐Salen (Co, Co 2 , Cu, Cu 2 ) with carboxylic groups were embedded into a Zr‐MOF (NKM‐908) by replacing the terminal coordinated ‐OH ‐ /H 2 O on the Zr 6 clusters. The integration of M‐Salen and NKM‐908 significantly accelerate the transfer dynamics of photogenerated charge and promote CO 2 enrichment around the M‐Salen active sites. The M‐Salen sites played a crucial role in enhancing CO production. Specifically, the mononuclear Co‐Salen exhibits stronger CO 2 adsorption and activation capabilities than the binuclear Co 2 ‐Salen, with enhanced *CO 2 coverage. In addition, the Co‐based salen catalyst exhibits a lower energy barrier for *CO desorption—the rate‐determining step—compared to its Cu‐based counterpart. As a result, the Co‐NKM‐908 exhibited optimal performance in photocatalytic CO 2 and H 2 O conversion, achieving a high CO production rate of 1.92 mmol g −1  h −1 and a H 2 production rate of 1.52 mmol g −1  h −1 with a standard syngas CO/H 2 ratio of 1.3/1.