Mg enhances the catalytic selectivity and stability of mordenite for carbonylation of dimethyl ether

Abstract

Mg species were introduced into the MOR zeolite to adjust its acid sites distribution, which has a great impact on the reaction of DME carbonylation. The introduction of Mg had a vital effect on the MOR structure, as it decreased specific surface area and pore volume. When Mg ion exchanged into both the 12MR channel and 8MR channel of MOR zeolite, the strong acid sites dramatically decreased, especially for the Brønsted acid sites in the 12MR channel. Mg modification inhibited most of active sites for side reactions, whereas decreasing a few active sites for carbonylation. This caused a little loss of activity, but the higher selectivity to methyl acetate (MA) product. Furthermore, Mg-MOR exhibited superior stability in the reaction of DME carbonylation. As a result, the MA yield on Mg-MOR was 3.8 times as higher as that on H-MOR.