Renewable methanol from CO2 over Cu/Zn/Zr/Si oxide catalysts promoted with Mg, Ce, or La

A series of multicomponent oxide catalysts (CuO/ZnO/MemOn/ZrO2/SiO2, with Me = Mg, Ce, or La) was synthesized through a one-pot soft-template approach and used for CO2 hydrogenation to methanol. In the case of the La-containing catalysts, additional samples were prepared with CuO contents in the range 40-60 wt%. The influence of the catalyst composition on the physicochemical properties as well as the effect on the catalytic performance were investigated. The fresh catalysts were characterized in terms of composition, structure, textural properties, dispersion of the oxidic phases, and reducibility. On the reduced samples, structural and acid-base properties were also investigated, as well as specific metal surface area and dispersion of Cu-0. After in situ H-2-treatment at 250 degrees C, the catalysts activity was tested in a bench scale plant at 250 degrees C and 3.0 MPa, using a gas hourly space velocity of 24,000 Ncm(3) h(-1) g(cat)(-1) and a H-2/CO2 molar ratio equal to 3. It was found that the production of methanol is particularly favored by the introduction of La2O3, the highest value of methanol space-time yield (413 mg(CH3OH) h(-1)g(cat)(-1)mg(CH3OH) h(-1)g(cat)(-1)) being obtained on the CuO/ZnO/La2O3/ZrO2/SiO2 catalyst containing 50 wt% of copper oxide.