Identification of the intermediate involved in methanol synthesis by gaseous titration

Abstract

This paper reports the hydrogenation of a formate species adsorbed on the copper component of an industrial (ICI) Cu/ZnO–Al2O3 methanol synthesis catalyst. The formate species is produced by the adsorption and reaction of a CO2–H2 mixture at 473 K, cooling the gas to ambient temperatures, before quantifying the formate coverage by temperature-programmed desorption. This same formate species reproduced by the identical method has been hydrogenated by temperature-programmed reaction. The product of that reaction was methanol, an exact carbon balance being obtained between the formate coverage and the methanol produced. Hydrogenation of the formate occurs at temperatures below which formate decomposes.