Bimetallic synergistic catalysis in MOFs toward transforming CO2 into carbonates with a record turnover number

The synthesis of asymmetric carbonates from renewable CO 2 is important for sustainable chemistry but often suffers from low efficiency, harsh reaction conditions, and noble metal catalysts. Achieving this efficient transformation under mild conditions by non-noble metal catalysts remains a great challenge. Herein, a framework {[In 3 ( μ 3 -O)(H 2 O)Cu 4 (CPT) 4 I 2 ]⋅(NO 3 )⋅1.5H 2 O⋅3DMF} n (CuIn-CPT, CPT = 3,5-bis(4′-carboxyphenyl)-1,2,4-triazole) was synthesized, assembled from a [Cu 12 In 18 ] nanocage with multiple Cu I and In III Lewis acid sites, and it exhibits good thermal and chemical stabilities. It achieves up to 98% yield in multicomponent reactions of CO 2 , propargyl alcohols, and primary alcohols without solvent under mild conditions, with a record turnover number of 4,844—ten times higher than top Ag-based catalysts—and excellent recyclability over 10 cycles. Density functional theory (DFT) calculations and mechanistic studies confirm that the synergistic effect between [Cu 4 ] and [In 3 ] clusters enhances catalytic efficiency. This work provides an inspiration for developing efficient non-noble metal heterogeneous catalysts in CO 2 conversion.