A Combined Experimental and Theoretical Study on the Hydrolysis of Dimethyl Ether over H-ZSM-5

The catalytic hydrolysis of dimethyl ether (DME) over H-ZSM-5 was examined by experimental and theoretical studies. We experimentally observed that this reaction yields methanol as major product at low temperature (–1, respectively. For the concerted manner, the demethylation and hydrolysis take place simultaneously in a single step without forming the intermediate by using the activation barrier of 108.9 kJ·mol–1. It was predicted that DME is preferentially hydrolyzed via a concerted mechanism and the rate-determining step is the DME demethylation step. The calculated apparent activation barrier for the DME hydrolysis is 75.5 kJ·mol–1, which agrees well with our experimental observation that DME hydrolysis over H-ZSM-5 required energy of 76.5 kJ·mol–1.