Benzene alkylation with methanol over phosphate modified hierarchical porous ZSM-5 with tailored acidity

The acidity and acid distribution of hierarchical porous ZSM-5 were tailored via phosphate modification. The catalytic results showed that both benzene conversion and selectivity of toluene and xylene increased with the presence of appropriate amount of phosphorus. Meanwhile, side reactions such as methanol to olefins related with the formation of by-product ethylbenzene formation and isomerization of xylene to meta-xylene were suppressed efficiently. The acid strength and sites amount of Bronsted acid of the catalyst were crucial for improving benzene conversion and yield of xylene, whereas passivation of external surface acid sites played an important role in breaking thermodynamic equilibrium distribution of xylene isomers. (C) 2017 The Chemical Industry and Engineering Society of China, and Chemical Industry Press. All rights reserved.