An Efficient Bifunctional Core–Shell MIL-101(Cr)@MOF-867 Composite to Catalyze Deacetalization–Knoevenagel Tandem Reaction

By growing one metal organic frameworks (MOFs) on different metal organic frameworks plays an important role in catalytic reaction, but its cooperative catalysis in tandem reaction is an undeveloped field yet, and the reports are very limited. In this work, the material MIL-101(Cr)@MOF-867 with core–shell structure was constructed by growing MOF-867 on the ultra-stable MIL-101(Cr). The synthesized core–shell material had acid–base sites at the same time. Thus, the synergistic catalysis of deacetalization-Knoevenagel tandem reaction showed good catalytic performance and obtained ultra-high yield. In addition, all experiments showed that the core–shell catalyst MIL-101(Cr)@MOF-867 had high stability and under the same conditions, the activity remained still high after five cycles. At the same time, this is the first time to apply MIL-101(Cr)@MOF-867 catalyzing deacetalization-Knoevenagel tandem reaction. Graphical Abstract A bifunctional material with core–shell structure was successfully synthesized. The obtained MIL-101(Cr)@MOF-867 with both acid and base sites showed ultra-high conversion in the deacetalization-Knoevenagel tandem reaction, thanks to the Lewis acid sites catalytic deacetalization reaction provided by Cr and Zr clusters and the Brönsted base sites to catalyze Knoevenagel reaction provided by pyridine. Fortunately, after five cycles of experiments, all the characterization showed that it still maintained ultra-high catalytic performance and stability. In addition, this is the first time to catalyze the deacetalization-Knoevenagel tandem reaction by MIL-101(Cr)@MOF-867.