Promotion effect of Fe in mordenite zeolite on carbonylation of dimethyl ether to methyl acetate

Abstract

A series of Fe-modified mordenite zeolite samples were synthesized by a template-free method and employed in dimethyl ether (DME) carbonylation reaction for the production of methyl acetate (MAc). XRD, UV-Vis, and UV-Raman characterization studies proved that Fe atoms have been introduced into the mordenite zeolite framework by partial substitution of Al atoms, which led to evident changes of activity and MAc selectivity. With the increase of iron content (as metal) from 0.0 to 3.6 wt%, DME conversion first increased and then decreased. MAc selectivity and catalyst stability were enhanced for all Fe-modified samples. TG and GC-MS analysis of deactivated catalysts showed that the amount of coke retained in the catalysts decreased as the iron content of the zeolites increased. The enhancement effects were expounded in terms of the decrease of the acid strength and acid density in the 12MR channels of mordenite after introduction of Fe, resulting in the reduction of carbon deposition.