Construction of Terminal Exposed Ti Active Sites Based on Aluminum Oxo Cluster Supports for Visible‐Light‐Driven CO 2 Photoreduction

Abstract Maximize the exposure of Ti active sites in titanium‐oxo clusters (TOCs) has been considered as the key to highly efficient photocatalytic CO 2 reduction. However, the fast aggregation rate of Ti 4+ greatly limits its realization. Herein, we reported a universal strategy to precisely immobilize and disperse Ti via aluminum oxo clusters (AlOCs) supports. Leveraging the coordination‐delay effects of alcohol solvents to modulate the differentiated aggregation kinetics of Ti 4+ and Al 3+ , we successfully induced the priority assembly of Al 3+ into AlOC supports, and further immobilized Ti on it in a terminal‐exposed mode. Based on this strategy, we successfully synthesized a structural well‐defined Ti 4 Al 6 cluster, which featured a natural θ‐Al 2 O 3 ‐like support. This support platform can be readily modified for functionalization (such as incorporation of ferrocene) or realizing single Ti dispersity. The optimal catalyst, Ti 2 Al 4 ‐Fc (featuring a γ ‐Al 2 O 3 ‐like support, Fc = ferrocenecarboxylate) realized a high Ti turnover frequency of 2.4 h −1 in visible‐light‐driven CO 2 photoreduction, significantly higher than many reported Ti‐based photocatalysts. This work provides a new paradigm for designing metal‐oxo cluster‐based photocatalysts with atomic dispersity and high atomic utilization.