Supported 12-tungstophosphoricacid: An efficient and selective solid acid catalyst for tert-butylation of phenol and cresols

摘要

12-Tungstophosphoricacid (30%) supported onto zirconia was synthesized by impregnation. The synthesized catalyst was characterized by solid state NMR and XPS in order to study the nature of active species on support surface. The acidity of the catalyst was measured by temperature programmed desorption (TPD) of NH3. Liquid phase alkylation of phenol and cresols with tert-butyl alcohol was carried out using fresh as well as calcined catalyst under mild conditions. The catalysts show high activity in terms of conversion and selectivity for the desired product under mild conditions. The process could be economically viable as the un-reacted phenol could be separated by simple distillation and reused for further reaction. Studies also reveal that the regenerated catalyst could be used for achieving high yield transformation.