Reusable and Efficient PS-Supported Acidic Ionic Liquid Catalyst for Mononitration of Toluene

A polystyrene-supported 1-(propyl-3-sulfonate)-3-methy-imidazolium hydrosulfate acidic ionic liquid (PS-[SO3H-PMIM][HSO4]) catalyst was prepared by grafting and characterized by FT-IR, SEM/TEM, elements analysis, TG/DSC and acid base titration. It exhibited higher catalytic activity and improved para-selectivity than its homogenous counterpart for the nitration of toluene with 68% nitric acid. The catalytic activity of this catalyst decreased slightly after fifth runs in the synthesis of nitrotoluene.