Theoretical Study for Adsorption-Diffusion on H-MOR and Pyridine Pre-adsorbed H-MOR of Dimethyl Ether Carbonylation

Jiabao Zhao; Weixin Qian; Hongfang Ma; Weiyong Ying; Peiqing Yuan; Haitao Zhang

doi:10.1021/acsomega.3c02127

Theoretical Study for Adsorption-Diffusion on H-MOR and Pyridine Pre-adsorbed H-MOR of Dimethyl Ether Carbonylation

ACS Omega. 2023 Jun 7;8(24):22067-22076. doi: 10.1021/acsomega.3c02127. eCollection 2023 Jun 20.

Authors

Jiabao Zhao¹, Weixin Qian¹, Hongfang Ma¹, Weiyong Ying¹, Peiqing Yuan¹, Haitao Zhang¹

Affiliation

¹ Engineering Research Centre of Large Scale Reactor Engineering and Technology, Ministry of Education, State Key Laboratory of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, People's Republic of China.

Abstract

For dimethyl ether (DME) carbonylation, pyridine pre-adsorbed hydrogen mordenite (H-MOR) is beneficial to prolonging the catalyst life. The adsorption and diffusion behaviors on periodic models H-AlMOR and H-AlMOR-Py were simulated. The simulation was based on Monte Carlo and molecular dynamics. The following conclusions were drawn from the simulation results. The adsorption stability of CO in 8-MR is increased, and the adsorption density of CO in 8-MR is more concentrated on H-AlMOR-Py. 8-MR is the main active site for DME carbonylation, so the introduction of pyridine would be beneficial for the main reaction. The adsorption distributions of methyl acetate (MA) (in 12-MR) and H₂O on H-AlMOR-Py are significantly decreased. It means the product MA and the byproduct H₂O are more easily desorbed on H-AlMOR-Py. For the mixed feed of DME carbonylation, the feed ratio (P_CO/P_DME) must reach 50:1 on H-AlMOR so that the reaction molar ratio can reach the theoretical value (N_CO/N_DME ≈ 1:1), while the feed ratio on H-AlMOR-Py is only up to 10:1. Thus, the feed ratio can be adjusted, and raw materials can reduce consumption. In conclusion, H-AlMOR-Py can improve the adsorption equilibrium of reactants CO and DME and increase the concentration of CO in 8-MR.