Liquid-phase methanol carbonylation catalyzed over tin promoted nickel-aluminium layered double hydroxide

A nickel-aluminum layered double hydroxide (LDH), of which structure is similar to that of hydrotalcite, has been synthesized. Liquid-phase carbonylation of methanol to methyl acetate is catalyzed over the LDH in presence of methyl iodide at 473 K. Dimethyl ether is also formed in the reaction, but formation of acetic acid is undetectable. Nickel ions in the LDH can be replaced with tin ions, and the presence of tin significantly promotes the activity of the LDH. Formation of methyl formate depends on the pressure of carbon monoxide in the reaction, suggesting that insertion of carbon monoxide to methyl iodide is a key step of the carbonylation and dimethyl ether reacts with the intermediate to form methyl formate. (C) 2004 Elsevier B.V. All rights reserved.