Stable and eco-friendly solid acids as alternative to sulfuric acid in the liquid phase nitration of toluene

A stable and eco-friendly solid acid catalyst, silica supported Cs2.5H0.5PMoO40 was prepared through a sol-gel method and successfully used as alternative to sulfuric acid in liquid-phase nitration of toluene. The evaluated catalysts exhibited high catalytic conversion of toluene and good mono-nitration selectivity. The strong acidity of the evaluated catalysts may be responsible for the excellent catalytic activity.