The Highly Selective Conversion of Toluene into 4-nitrotoluene and 2,4-Dinitrotoluene Using Zeolite H-Beta

摘要

The nitrationof toluene was studied in the vapour and in the liquid phase to assess the potential of various zeolites and solid acids for replacing sulfuric acid. Zeolite beta in its proton form provided a higher para-to-ortho ratio in the nitrationof toluene to nitrololuene (NT) compared to other catalysts. Enhanced para-selectivity was also observed for the formation of dinitrotoluene (DNT) using H-beta and acetyl nitrate in the liquid phase. Characterisation and adsorption studies suggest that the high para-selectivity originated from steric hindrance of the ortho position induced by adsorption rather than from classical transition state selectivity.