Effect of Calcination Temperatures of Cu/CeO sub(2)-Containing Co on Physiochemical Properties and Catalytic Activity to Selective CO Oxidation

The CuO/CeO sub(2)-Co sub(3) O sub(4) catalysts were prepared via co-precipitation at different calcination temperatures and evaluated catalytic activities in the reaction of selective CO oxidation. The catalysts were characterized by BET, XRD and FESEM-EDX techniques. As determined by BET studies, the catalysts have type IV adsorption isotherm which indicated mesoporous structure. An increase in calcination temperatures decreased the specific surface areas of the catalysts. XRD was used for determination of crystallite sizes of each oxide. It was found that CuO and Co sub(3) O sub(4) existed in highly dispersed at every calcination temperatures. For CeO sub(2), an increase in calcination temperatures increased the crystallite sizes. Surface morphology of the catalysts was also investigated by FESEM. The catalyst calcined at 500[degrees]C showed the highest performance to completely convert CO to CO sub(2) at 150[degrees]C. Furthermore, the effect of CO sub(2) and H sub(2) O to activity of catalyst was studied. The result showed that both CO sub(2) and H sub(2) O has negative effect to activity of catalyst. CO conversion and selectivity decreased to 93.8% and 48.5% at 210[degrees]C, respectively. This may be due to the adsorption of CO sub(2) and H sub(2) O molecules on active site and due to the reverse water gas shift reaction occurred at temperature above 190[degrees]C.