A 13CO isotopic study on the CO promotion effect in methane dehydroaromatization reaction over a Mo/HMCM-49 catalyst

The promotion effect of CO in methane dehydroaromatization was investigated using 13CO probe molecules. By alternative injection of 13CO to the methane feed, the distribution of 13CxC6-xH6 (x = 0-3) products changed significantly, confirming the participation of 13CO in the reaction network. The addition of 13CO did not change the conversion of CH4 but improved slightly the durability of the methane dehydroaromatization (MDA) reaction, which might be caused by the interaction of the dissociated oxygen species and the deposited carbon species. The ratio of 13CxC6-xH6 (x = 0-3) varied with the time on stream, which was determined by the competitive reactions of methane decomposition and 13CO dissociation.