Dehydrogenation and Condensation in Catalytic Conversion of iso-Propanol over CuO/MgO System Doped with Li2O and ZrO2

The effects of Li2O and ZrO2-doping on the surface and catalytic properties of CuO/MgO system have been investigated. The dopant concentration was changed between 0.6 and 3.6 mol % Li2O and that of ZrO2 between 2.4-7.7mol %. Pure and variously doped solids were calcined at 673 and 773 K. The techniques employed for characterization of different solids were XRD, nitrogen adsorption at 77 K and catalytic conversion of iso-propanol at different reaction temperatures ranged between 423 and 573 K. The results revealed that the addition increasing amounts of dopant (Li2O and ZrO2) to CuO/MgO solid led to an increase in the degree of dispersion of CuO phase and a decrease in the specific surface areas of the investigated solids. Li2O and ZrO2–doping increases the catalytic conversion of iso-propanol, which proceeds mainly via dehydrogenation to give acetone and aldol condensation of the produced acetone to give methyl isobutyl ketone (MIBK). Doping with 1.2 mol % Li2O for the solids calcined at 673 K increases both of total conversion and selectivity to MIBK at reaction temperature 473 K with 24 % and 25 %, respectively. Doping with 7.7 mol % ZrO2 for the investigated solids calcined at 673 K increases both of total conversion and selectivity to MIBK at reaction temperature 473 K with 32 % and 99 %, respectively.