Vapour phase reaction of ethylbenzene with diethyl carbonate over Al-MCM-41 supported phosphotungstic acid

The vapour phase ethylation of ethylbenzene with diethyl carbonate was studied over Al-MCM-41 and 10, 20 and 40 wt% PW loaded Al-MCM-41 catalysts. Based on the conversion 20 wt% PW/Al-MCM-41 was found to be more active than others. Diethylbenzene isomers were found to be more predominant than tri-, tetra-, penta- and hexa- alkylated products. The formation of hexaethylbenzene suggested high density of ethyl cations on the catalyst surface. The feed ratio of 2:1 (ethylbenzene:diethyl carbonate) was observed to yield 100 % selectivity of diethylbenzene isomers. Although ortho, meta and para diethylbenzene isomers were observed, the selectivity to para isomer was found to be higher than other isomers.