Investigation of the coupled reaction of methyl acetate and n-hexane over HZSM-5

The coupled reaction of methyl acetate and n-hexane was carried out over a HZSM-5 catalyst. In addition to a thermal coupling effect, systematic variations in the product distribution were also observed in the coupled system. The bezene-toluene-xylene (BTX) selectivity was remarkably improved while the H2, CO, and CO2 selectivity decreased. Rapid deactivation of the catalyst was observed, caused by the extremely high reactivity of methyl acetate, which was alleviated after adding n-hexane. These results indicated that a coupling effect exists in this system. A detailed pathway for the coupled system is suggested based on the analysis of the surface species, carbonaceous species deposited on the catalyst, as well as the product selectivity changes. The good match between the “hydrogen deficiency” of methyl acetate and the “hydrogen richness” of n-hexane is consistent with the observed coupling effect.