Hydrogenation of CO2 toward Methanol Influence of the catalysts composition and preparation on the catalytic behavior

The influence of the preparation method of methanol catalysts composed of copper associated with rare earth oxides (eg Cu-La2Zr2O7 and ZnO promoted Cu-La2Zr2O7 systems) on the catalytic behaviour is discussed. Good activities and improved aging properties are always associated with a high copper surface area and a reasonnable crystallinity of the La2Zr2O7 pyrochlore. For Cu-La2Zr2O7, as well as for Cu-ZnO catalysts, an almost linear correlation can be observed between the methanol yield, the copper surface al ea and the amount of formates located on the catalyst's surface. A similar correlation cannot be evidenced on ZnO promoted Cu-La2Zr2O7 catalysts. The results are discussed and a mechanism for the hydrogenation of: CO2 to methanol is proposed.