Selective dealumination of mordenite for enhancing its stability in dimethyl ether carbonylation

• Selective dealumination of HMOR was achieved by using Na+ as the compensate cation.
• Most of the framework Al in the 12-MR of HMOR was selectively removed.
• HMOR catalyst after selective dealumination showed a much greater stability in DME carbonylation.
• Deposition of hard coke was suppressed on HMOR after selective dealumination.

Selective dealumination of mordenite by high-temperature steam treatment improved its stability in dimethyl ether carbonylation. Most of the framework Al species in the 12-membered ring channels of mordenite was removed while those in the 8-membered ring channels were retained. On the resulting mordenite catalyst, the formation rate of methyl acetate was only slightly decreased and maintained at 1.71 mol (mol H+)− 1 h− 1 at 15 h. Temperature-programmed oxidation analyses on the used sample evidenced that the deposition of hard coke was effectively suppressed in the selectively dealuminated catalyst because of the reduced number of acidic sites in the 12-membered ring channels.

Figure optionsDownload as PowerPoint slide