Vapor phase alkylation of toluene using various alcohols over H_3PO_4/MCM-41 catalyst: influence of reaction parameters on selectivity and conversion

A mesoporous MCM-41 molecular sieve material with a molar ratio of SiO_2 /Al_2O_3= 70 and loaded with H_3PO-4 was used as a catalyst for the alkylation of toluene, using various alcohols, namely methanol, iso-propanol, and tert -butanol, as alkylating agents. Para-alkylated toluene was the predominant product, formation of which was enhanced by moderate temperature, low amounts of the alkylating agents in the feed, and high carrier gas flow rate. Time on stream was found to exert a profound effect on the selectivity and conversion to the different products.