Tailoring of Unsaturated Metal Sites in Metal–Organic Frameworks to Promote the Conversion of CO<sub>2</sub> into High-Value-Added Products
Chunlong Yu, Xinglei He, Chenxu Gong, Jingheng Li, Ke‐Yin Ye
Abstract
Well-defined metal–organic frameworks (MOFs) provide an attractive platform for catalysis. Understanding the intrinsic structure–activity relationship of MOFs helps guide the design of novel catalysts. In this work, a new three-dimensional (3D) Mn II (salen)-based MOF ( 1 ) with strong adsorption capacity and high selectivity for CO 2 was synthesized. Through sequential demetallization and remetallization, the flexible tailoring of the metal centers was realized to obtain a series of remetallized MOFs ( r1 M; M = Mn, Co, Cu, Ni, V). Among them, r1 Co was proved to be the most active catalyst for the cycloaddition of CO 2 and epoxides. Mechanistic studies reveal that r1 Co displays a high CO 2 affinity and Lewis acidity. In addition, kinetic studies suggest that r1 Co has a lower activation energy than the original MOF ( 1 ) and demetallized MOF ( d1 ). Remarkably, r1 Co could be reused five times without affecting its catalytic activity.