Dimethyl ether Carbonylation over Mordenite zeolite modified by Alkyimidazolium ions

Acidic mordenite zeolite was modified with various alkyimidazolium ions with different sizes via ion-exchange and applied as dimethyl ether (DME) carbonylation catalysts. Introducing 1, 3-dimethylimidazolium ions into zeolite can selectively remove the acid sites in 12-membered ring (MR) channels, significantly enhancing the stability and activity. Additionally, ion-exchange with organic ions was used to control the acid site distributions to separately investigate the DME carbonylation reaction in 8-MR and 12-MR channels. The reaction results indicated that the acid sites in 12-MR channels can concurrently catalyze the carbonylation and methanol-to-hydrocarbons (MTH) reactions, and MTH reactions seriously suppress the carbonylation activity in 8-MR channels.