One-pass conversion of benzene and syngas to alkylbenzenes by ZnAlO_x/ZSM-5 composite catalyst

Alkylbenzenes are important bulky chemicals. The production of alkylbenzenes through benzene and syngas alkylation technology of coal chemical industry can reduce the domestic dependence on petroleum. In this study, mechanical mixture of ZnAlO_x and ZSM-5 were used to catalyze the alkylation reaction of benzene and syngas. The results showed that the best performance catalyst was obtained with the 1∶1 mass ratio of the two components and the 2∶1 molar ratio of zinc to aluminum. It was suggested that the main reaction intermediates of methanol and dimethyl are produced on the O vacancy of ZnO and L acidic center of Al₂O₃ in ZnAlO_x. And the alkylated benzenes are formed by the reaction of benzene with the intermediates over ZSM-5. Due to the high temperature property of ZnAlO_x for methanol synthesis which can accommodate to the reaction of ZSM-5 for benzene alkylation, the high catalytic activity and selectivity was obtained.