Dehydrogenation Reactions of Methanol in Presence of Nanosized-ZnO/CuO/MgO System

The effect of ZnO-doping (0.04-0.08 mol) on the physicochemical and catalytic properties of CuO/MgO catalyst calcined at 350-650^oC was investigated. Pure and doped catalysts were prepared by wet impregnation method. The prepared solids were characterized by X-ray Diffraction (XRD), N₂-adsorption at -196 ^oC and the methanol conversion as the catalytic probe reaction. The results revealed an observed decrease in the crystallite size of CuO phase by doping with amounts < 0.08 mol ZnO.  Increasing the calcination temperature from 350 to 650 °C increased the crystallite size of CuO (4.7 to 25 nm). The specific surface area (S_BET) and the catalytic activity of un-doped catalyst increased by increasing the amounts of ZnO up to certain extent reaching to a maximum at 7.07 wt % ZnO, above this concentration catalytic activity decreased. The catalytic activity of pure and doped solids was affected by increasing the calcination temperature. The prepared catalysts are selective towards formaldehyde and methyl formate formation.