The Synthesis of Dimethyl Carbonate by the Oxicarbonylation of Methanol Over Cu Supported on Carbon Norit

Abstract

The catalytic activity of Norit supported Cu, Ni and Cu–Ni catalysts was investigated in the synthesis of dimethyl carbonate (DMC) by the oxidative carbonylation of methanol. Cu/Norit showed the best catalytic activity. The reaction was carried out in a continuous flow system at atmospheric pressure usually at 393 K. The main products were methyl formate, DMC and CO2. The methanol conversion on Cu/Norit achieved in steady state was about 22 % and the DMC yield 13.2 %. Based on the XPS data we can establish that copper reduced to its metallic form during reduction but oxidized in the reaction mixture, and is mostly in the Cu+ state, with some Cu2+. It is possible that the DMC formation rate depends on the surface concentration of oxidized Cu and on the ratio of Cu+ and Cu2+. Based upon the IR measurements adsorbed DMC was found on the surface of the Cu/Norit catalyst during the catalytic reaction.