Journal of Catalysis, Vol.359, 198-211, 2018
Improving the selectivity to 4-tert-butylresorcinol by adjusting the surface chemistry of heteropolyacid-based alkylation catalysts
Keggin tungstophosphoric acid (H3PW12O40, HPW) was immobilized onto Santa Barbara Amorphous (SBA-15) type silica to obtain selective catalysts for the resorcinol tert-butylation with methyl-tertbutyl ether. The challenge was to enhance the reaction selectivity to the mono-alkylated product i.e. 4-tert-butylresorcinol at the expenses of other more thermodynamically favored products as the 4,6-di-tert-butylresorcinol. Using HPW@SBA15 catalysts, remarkable selectivity to 4-tert-butylresorcinol was obtained, up to 42% (at 20% of resorcinol conversion). Our finding is that the change in the product distribution was dependent on the catalyst surface chemistry: 4TBR selectivity can be increased adjusting the fraction of Bronsted acid sites versus Lewis ones at the catalyst surface. (C) 2018 Elsevier Inc. All rights reserved.