Construction of mesoporous dual-metal MOFs by a facile in-situ hydrogel-templated method for boosting CO₂ conversion

Compared with the counterparts with mononuclear metal sites, catalysts featuring dual-metal sites with suitable metal-metal distance have shown superiority in enhancing catalytic performance. However, most of heterogeneous dual-metal catalysts are characterized by poor long-range order structures, particularly when obtained via pyrolysis. Furthermore, sophisticated and complicated design of ligand is usually involved for the synthesis of catalysts with dual-metal sites. Herein, a series of mesoporous ZnCo zeolitic imidazolate frameworks were prepared through a facile in-situ hydrogel templated method. Partially replacement of Zn antenna by Co ions leads to boosted CO₂ photocatalytic conversion. CO yield over optimized ZnCo reached 2064.9 μmol·g^-1·h^-1 during the second hour of light illumination, which is 67.9-fold higher than the value of corresponding bare bulk Zn-base ZIF under the same reaction conditions. Parallel control experiments confirmed the critical roles of Zn/Co active sites and the synergistic effect between them, which were further elucidated by in situ characterizations. This work demonstrates a straightforward strategy for construction mesoporous dual-metal-sites MOFs and highlights their potential as an ideal platform for CO₂ conversion.