The effect of the preparation method of Pd-doped cobalt spinel on the catalytic activity in methane oxidation under lean fuel conditions

Although NG is one of the cleanest hydrocarbon fuels, the complete oxidation of CH4 from compressed NG-fuelled engines is still an open issue. Catalysts for CH4 combustion undergo very demanding conditions: they must resist thermal and mechanical shocks and exhibit high activity, as CH4 molecules show great stability and the temperature of the exhausts in CNG vehicles is relatively low (it seldom exceeds 500°C). Many catalysts have been used for the combustion of CH4, with platinum and palladium being the most common active metals, although also perovskites or perovskites with noble metals have been employed. Recently attention has increasingly focused on the development of cobalt oxide based powders. These powders have high potential for use as catalysts, gas sensors, magnetic materials, rechargeable batteries, pigments for ceramics, solar energy absorbers and electrochemical devices. Cobalt(II,III) oxide Co3O4 and cobalt(II) oxide (CoO) particles are largely prepared by a wide assortment of wet chemical techniques like freeze drying, spray pyrolysis, co-precipitation, solubility-controlled synthesis, sol-gel. On the contrary, there are not many studies of cobalt oxide particles obtained by solution combustion synthesis (SCS).