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

For dimethyl ether (DME) carbonylation, pyridine pre-adsorbedhydrogenmordenite (H-MOR) is beneficial to prolonging the catalyst life. Theadsorption and diffusion behaviors on periodic models H-AlMOR andH-AlMOR-Py were simulated. The simulation was based on Monte Carloand molecular dynamics. The following conclusions were drawn fromthe simulation results. The adsorption stability of CO in 8-MR isincreased, and the adsorption density of CO in 8-MR is more concentratedon 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) andH(2)O on H-AlMOR-Py are significantly decreased. It meansthe product MA and the byproduct H2O are more easily desorbedon 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 reachthe theoretical value (N (CO)/N (DME) approximate to 1:1), while the feed ratio on H-AlMOR-Pyis only up to 10:1. Thus, the feed ratio can be adjusted, and rawmaterials can reduce consumption. In conclusion, H-AlMOR-Py can improvethe adsorption equilibrium of reactants CO and DME and increase theconcentration of CO in 8-MR.

Automated summary

Through simulation experiments, it was found that pyridine pre-adsorbed hydrogen mordenite can prolong the catalyst life of dimethyl ether carbonylation. The introduction of pyridine can enhance the main active site for the reaction and facilitate the desorption of products and byproducts, leading to reduced raw material consumption.