Nitration of o-xylene over rare earth cations exchanged zeolite-β with nitric acid and acetic anhydride

Liquid phase nitration of o-xylene was studied with sulfated silica, sulfated zirconia, zeolite H-β and rare earth cations exchanged zeolite-β with nitric acid and acetic anhydride/1,2-dichloroethane as solvent. H-β and rare earth exchanged zeolite-β were found to be efficient solid acid catalysts both in acetic anhydride and 1,2-dichloroethane. Nitration with nitric acid and acetic anhydride via acetyl nitrate as nitrating species is efficient and preferable rather than reaction in 1,2-dichloroethane solvent. Among the lanthanides studied Ce-β gave maximum conversion 86% with 58% para selectivity in acetic anhydride. The catalyst can be easily recovered and regenerated thus providing economic and environmentally friendly method for nitration reaction.

The catalytic activity of rare earth cations exchanged zeolite-β was studied for the nitration of ortho-xylene with acetic anhydride and dichlorethane as solvents in liquid phase. Higher conversion observed with acetic anhydride solvent is explained in terms of acetyl nitrate formed as intermediate species. Figure optionsDownload high-quality image (77 K)Download as PowerPoint slide