Studies on some physicochemical, surface and catalytic properties of CuO - ZnO/Al2O3 system prepared by coprecipitation

ABSTRACT

Four copper - zinc aluminium mixed oxides having different composition were prepared by coprecipitation method. The prepared solids were calcined at 400 - 800 degree C. Some physicochemical, surface and catalytic properties of the systems investigated were studied using XRD, EDX, nitrogen adsorption at 196 degree C and catalytic oxidation of CO by O2 at 100 - 200 degree C.The results revealed that all investigated solids consisted of nanocrystalline CuO and ZnO phases even those calcined at 800 degree C.The surface characteristics of different adsorbents were strongly dependent on their chemical composition and calcination temperature. The SBET decreased by increasing both the copper oxide content and calcination temperature. The value of 132m 2/g was computed for the system containing the smallest amount of CuO and being calcined at 400 degree C. The activation energies of sintering for different solids were determined from the values of SBET as being influenced by calcination temperature. The catalytic activities, in CO - oxidation by O 2, for all solids were found to increase by increasing both CuO content and calcination temperature. The activation energies of the reaction have been determined