Effect of CO2 on the catalytic performance of Zn/ZSM-5 towards the conversion of methanol to aromatics

The selectivity of methanol conversion to aromatics on Zn/ZSM-5 is often limited, mainly because the hydrogen removed during the process combines with low-carbon olefin intermediates to regenerate alkanes and reduce the effective utilization of carbon atoms. Herein, CO 2 is added to the methanol aromatization reaction as a receptor that consumes hydrogen in situ, which reduces the hydrogen transfer reaction and improves the selectivity of aromatics. It is proposed that aromatic selectivity under CO 2 atmosphere is determined by the chemical state of Zn species. Specifically, ZnO converts CO 2 and consumes hydrogen, and ZnOH + promotes methanol aromatization. Under the same conditions, aromatic selectivity of 3ZnZ18-IM under CO 2 atmosphere can reach 85.2 %, which is much higher than that of 71.4 % under N 2 atmosphere. This study provides a new strategy for methanol to aromatics (MTA) reaction, which has a positive impact on solving the energy and environmental problems in the production of aromatics.