Design and Assembly of a Hierarchically Micro- and Mesoporous MOF as a Highly Efficient Heterogeneous Catalyst for Knoevenagel Condensation Reaction

A 3D hierarchically micro- and mesoporous MOF, [Tb6(μ3-OH)8·(2-FBA)2·(H2O)6·(DCBA)2]·10DMF·4H2O (namely, Tb-DCBA), was successfully constructed by the coordination self-assembly process between H4DCBA linker and Tb6 hexanuclear cluster. By virtue of preferable physicochemical stability, high surface area, multiple porosity, and abundant amino functional groups, Tb-DCBA is not merely considered as a greatly potential heterogeneous catalyst for Knoevenagel condensation reaction, but also has remarkable repeatability for reusing at least four times. It is worth noting that micro- and mesoporous MOF is still an urgent and enormous challenge, because such MOFs are difficult to synthesize and determine precise structures, and always possess relatively poor stability to limit their practical applications. Hence, this work creates a scarce opportunity for a hierarchically micro- and mesoporous MOF for investigating its catalytic performance.