Promoting the activity of Ce-incorporated MOR in dimethyl ether carbonylation through tailoring the distribution of Brønsted acids

Abstract

As Brønsted acid site (BAS) located in 8-membered ring (8-MR) of zeolite is accepted as the exclusive active site for dimethyl ether carbonylation to methyl acetate, tailoring the distribution of tetrahedral Al in zeolite channels is important to improve catalytic performance. In this work, a series of Ce-containing mordenite were synthesized by one-step hydrothermal method. By a combination of mutually complementary characterization techniques (e.g. XPS, UV–vis, Raman, acidity characterizations etc.), it is confirmed that Ce atoms incorporated into the zeolite framework as Ce3+ species, resulting in an enrichment of BAS in the 8-MR. Acid strength, apparent activation energy and DFT calculations revealed that the incorporation of Ce resulted in an increase of SiOHAl in the 8-MR, which was responsible for the improved activity. This work provides a facile way to tailor the acidic concentration and distribution of zeolites, which is able to guide rational design of zeolites for the shape-selective catalysis.