Selective gas phase tert-butylation of 4-hydroxyanisole over mesoporous PWA/Al-MCM-41 molecular sieves

Mesoporous Al-MCM-41 and phosphotungstic acid (PWA) impregnated Al-MCM-41 samples were prepared and characterized by various physiochemical techniques like XRD, N2 adsorption isotherm, FT-IR spectroscopy, pyridine adsorbed FT-IR, SEM-EDX and 27Al-MAS NMR spectroscopy. Their catalytic reactivity was tested for the gas phase tert-butylation of 4-hydroxyanisole (HA) with methyltertiarybutylether (MTBE) under atmospheric pressure in the temperature range of 200–450 °C. PWA was well dispersed in mesoporous Al-MCM-41 matrix and has yielded desired acidity for the reaction. Especially 20 wt%PWA/Al-MCM-41(25) catalyst prepared by wet impregnation technique showed maximum conversion of HA (58.2%) with a selectivity of 67.3% at 225 °C.