Template-free fabrication of magnetic mesoporous poly(ionic liquid)s: efficient interfacial catalysts for hydrogenation reaction and transesterification of soybean oil

Abstract

Green sustainable production is very important for the development of human society and the environment. In this study, Pickering interfacial catalysts (Pd-p(xTEMPA-yFDABCO-zDVB)@Fe₃O₄) with a CO₂ and magnetic double response were prepared by a template-free method for the first time. The introduction of terminal alkene modified Fe₃O₄@SiO₂ and 2,2,6,6-tetramethyl-4-piperidyl methacrylate (TEMPA), a CO₂ responsive functional group, not only improved the formation of the mesoporous structure and increased the specific surface area of the final catalyst but also accelerated the demulsification rate of the emulsion, which was beneficial to the separation of products and the recovery of catalysts. The application of the Pd-p(xTEMPA-yFDABCO-zDVB)@Fe₃O₄ in hydrogenation resulted in an excellent conversion (88–99%) at room temperature and atmospheric pressure. The double basic catalyst p(xTEMPA-y[FDABCO][OH]-zDVB)@Fe₃O₄, exploited as a catalyst for the transesterification of soybean oil with ethanol, was obtained by exchanging Br⁻ and OH⁻. These excellent performances are mainly due to the “microreactor” droplets formed by the Pickering emulsion and the mesoporous channels provided by the magnetic mesoporous poly(ionic liquid)s. On the other hand, the double responsive Pickering interfacial catalysts can be recycled at least 5 times without significant degradation in catalytic activity.