Enhancing the dimethyl ether carbonylation performance over hydrogen-type mordenites modified by pyrazole hydrochloride.

Hydrogen-type mordenite (HMOR) modified with pyrazole hydrochloride (Pya·HCl) was prepared by the ion exchange method. The results showed that Pya·HCl introduction significantly improved the activity and stability of HMOR in the carbonylation reaction of dimethyl ether (DME) to methyl acetate (MA). Small pyrazole ions (HPya+) entered into the twelve-membered ring (12-MR) pores of HMOR and selectively replaced part of the Brønsted acid (BAS), thus suppressing the formation of carbon deposits. The modified HMOR presented a larger specific surface area and pore volume, which provided larger channels for molecular diffusion. Additionally, non-framework aluminum was removed by the acidic Pya·HCl solution, resulting in the formation of mesopores, which facilitated the migration of carbon-deposited species from the inside of the zeolite to the outside.

Highly stable photoresponsive complex framework formation involves unusual selective hydrogenation of a pyridine derivative.

A unique hydrothermal selective hydrogenation process is carried out effectively in a simple and friendly way without adding any precious metal catalysts and hydrogen gas from outside. The self-assembly of the hydrogenated product 3-(4-(pyridin-4-yl)piperidin-1-yl) benzoate (PYPDB) with the zinc ion produces a highly stable photoactive complex Zn(PYPDB)2 displaying interesting long range electron transfer behavior in the conjugated ring system.