Study on the deactivation process of dimethyl ether carbonylation reaction over Mordenite catalyst

Abstract The deactivation of Mordenite (MOR) catalyst in dimethyl ether (DME) carbonylation reaction was systematically studied. The influence of coke deposition on the structure, morphology and acid sites were characterized and the transformation of coke deposition was investigated. Characterization results revealed that coke deposition had little effect on the structure and morphology of the catalyst. Soft and hard coke could be identified on the catalysts throughout the reaction process. The acid sites decreased more rapidly in the induction period of carbonylation reaction due to the formation of reaction intermediates and soft coke while the hard coke mainly accumulated in the deactivation period. C2H4 generated in the desorption process of DME and methyl acetate (MA) molecules were speculated as an important source of coke deposition. The soft coke was mostly formed via degradation of DME molecules at first half of reaction period, which gradually transformed into hard coke by releasing CH4 and H2. The hard coke mainly derived from MA molecules and transformation of soft coke.