Structural, surface and catalytic properties of pure and ZrO2-doped nanosized cobalt-manganese mixed oxides

The role of ZrO2‐doping of CoO–Mn2O3 system on its structural, surface and catalytic properties was studied using XRD, EDX, nitrogen adsorption at −196°C and H2O2‐decomposition at 30–50°C. The results revealed that all solids calcined at 300–500°C consisted of nanosized Co2MnO4 as a major phase together with Co3O4 phase. The surface and bulk compositions of pure and variously doped solids were completely different from each other's. The concentration of surface manganese species was much higher than that of cobalt. The addition of the smallest amount of ZrO2 (0.75 mol%) much increased the surface concentration of manganese species. The increase of calcination temperature of all solids increased progressively the catalytic activity which increased by doping with the smallest amount of ZrO2 then decreased by doping with further amounts of ZrO2 dopant falling to values smaller than that measured for pure sample.