Metal–organic frameworks as an efficient Pickering interfacial catalyst for the deacetalization-Knoevenagel tandem reaction

Abstract

Stabilizing Pickering emulsions with solid catalysts at the oil–water interface is one of the most effective ways to develop environmentally friendly chemical processes. In this study, metal–organic frameworks (ZIF-8, UiO-66(Zr)-NH₂, and MIL-101(Cr)-NH₂) with both Lewis acid and Brønsted base sites were synthesized to prepare Pickering emulsions to catalyse the deacetalization-Knoevenagel tandem reaction. Most importantly, the Pickering emulsion stabilized with ZIF-8 showed the highest catalytic activity and maintained good chemical stability. What is more, the spent Pickering emulsion could be easily reconstructed and it showed good reusability even after five cycles.