ON THE MECHANISM OF THE METHANOL SYNTHESIS INVOLVING A CATALYST BASEDON ZIRCONIA SUPPORT

The nature of the pivotal intermediate during the synthesis of methano l from CO2/H-2, in the presence of ZnO/ZrO2 aerogel catalyst is envisa ged. The kinetic studies performed using in situ FTIR spectroscopy of the species formed on the surface of the catalyst in the absence and i n the presence of hydrogen show that the initial reactive adsorbed spe cies formed from CO2 gas is the unidentate carbonate species. Its hydr ogenation into the formate species is much faster than the hydrogenati on of the formate species into methoxyl species. The comparison is bas ed on a quantitative measurement of the rate constant of the hydrogena tion of the various species. The results explain that during the CO2/H -2 reaction only formate and methoxyl species are observed.