Heteropoly acids-functionalized Janus particles as catalytic emulsifier for heterogeneous acylation in flow ionic liquid-in-oil Pickering emulsion

摘要

In this work, we developed a continuous non-aqueous flow Pickering emulsion interface catalysis (FPIC) system for heterogeneous acylation. Poly (1-vinyl-3-ethylimidazolium bromide) (PILs) functionalized silica@PS/PDVB Janus particles (JPs) were synthesized. The catalyst H3PW12O14 (PA) was then immobilized on PIL-modified JPs by anion-exchanging. The PIL grafted on the silica side and the inherent oleophilic phenyl groups on the other side endow the Janus particle with excellent amphipathy for the immiscible ionic liquid (IL) [BMIM]BF4 and toluene. Therefore, emulsification and catalytic capability were realized simultaneously on the PA-PILs-JPs. The FPIC column system for acylation reaction was accomplished by packing the IL-in-oil Pickering emulsion into a column reactor, and exhibited excellent catalytic performance, high stability during the reaction process as well as remarkable recyclability.