Zhiping Xiong and Dr. Ensheng Zhan in our group developed a new type zeolite for the carbonylation of dimethyl ether. This work was published in Chemical Communications.
This work is the first time for SUZ-4 to be used in the study of dimethyl ether carbonylation reaction. SUZ-4 has a 3-dimensional pore system with a 10-MR channel intersected by two arrays of 8-MR channels, and compared with the similar structure of ZSM-35 and ZSM-57 zeolites, its activity and stability were both maintained at a higher level. Characterized by high-resolution scanning and transmission electron microscopy, SUZ-4 showed a rod-like morphology growing along the  direction, exposing more 8-MR pores, and the 8-MR channel length was shorter, which was conducive to the reaction and the diffusion of product molecules, thus promoting the reaction. Then, the dimethyl ether adsorption experiment proved that dimethyl ether as the reactant molecule diffused faster in SUZ-4 channels, and the in-situ dimethyl ether carbonylation reaction infrared spectroscopy proved that the reaction on SUZ-4 was transformed into the product methyl acetate through acetyl intermediates, which was consistent with the mechanism occurring on other zeolites. We used GS-MS to characterize the catalyst after the reaction, and found that the carbonylation of dimethyl ether on SUZ-4 mainly formed soft carbon deposition, which also meant that the catalyst could be regenerated at a relatively low temperature, and the experiment also showed that the catalyst could be completely regenerated at 450℃. we developed a new type zeolite for the carbonylation of dimethyl ether with higher reaction activity and stability than ZSM-35, and also could be completely regenerated at a lower temperature, so that the catalyst could be reused more easily. This work also contributed a candidate for the carbonylation of dimethyl ether.
The research was funded by National Natural Science Foundation of China. (Text by Xiong Zhiping)