One-pot synthesis of bimetallic metal–organic frameworks (MOFs) as acid–base bifunctional catalysts for tandem reaction†
Designing and preparing effective acid–base tandem catalysts is one of the research hotspots at present because assembling antagonistic active sites in one catalyst is still a challenge. In this work, amine-functionalized bimetallic metal–organic frameworks (MIL-101(Al/Fe)–NH2 (X)) were synthesized through a rapid reflux method and acted as acid–base bifunctional catalysts for tandem reaction (deacetalization–Knoevenagel condensation reaction). The bimetallic MOF catalysts exhibit enhanced catalytic activity when compared with monometallic catalysts either MIL-101(Al)–NH2 or MIL-101(Fe)–NH2. The superior performance of MIL-101(Al/Fe)–NH2 (X) has been attributed to the synergistic effect between Al3+ and Fe3+ ions and the hierarchical pore structure. Moreover, the as-synthesised samples showed robust stability, excellent recyclability, and durable catalytic activity.