Recent Advances for Selective Catalysis in Benzene Methylation: Reactions, Shape-Selectivity and Perspectives

Benzene methylation over zeolite offers an alternative route to produce high-value toluene or para-xylene directly from benzene and C₁ chemical sources, especially for countries with a shortage of crude oil but abundant coal, natural gas, or biomass. It also serves as a green “molecular engineering” to reduce costs of energy intensive separation for C₈ isomers by selective catalysis. Since numerous zeolite-based catalysts have been synthesized, characterized and evaluated in alkylation process, this review aims to present the roles of the zeolite topology and acidity in selective catalysis based on the reaction network and mechanisms for benzene methylation system during the recent years. It covers concise details in the shape-selective catalysis of zeolite topology and acidity to provide a theoretical basis of the chemical modification under reaction conditions, which give directions to or identify the catalyst design for benzene methylation, and also will provide the mechanistic insights and technical reference as an integral part of other aromatics production.