Abstract:
The objective of this work is to study the activities of mixed oxidescontaining cobalt oxide as a catalyst for CO removal in reformed gas. The mixed oxides with varying amount of cobalt oxide were characterized for their specific surface areas, average pore diameters, chemical structure and average crystallite sizes. All samples were prepared by coprecipitation method. The BET results showed that the samples containing 85 cobalt ixide gave the highest specific surface area of 132.9m2/g. Moreover, this catalyst showed the best performance to CO oxidation. CO completely converted to CO2 at 170 degree Celsius. However, an increase in amont of cobalt oxide in the catalysts led to decreasing of specific surface area and decreasing in the acticity of the catalyst to the reaction. For selective CO oxidation, the same catalyst has shown the highest activity and selectivity to CO oxidation in the presence of 50% H2 in the gas feed. The effect of the presence of CO2, H2O and concentration of CO and O2 to the catalytic activity of the catalyst was also investigated. The results showed that both CO2 and H2O have negative to the activity. This could be due to the physical adsorption at reaction temperature below 150'C and the formation of CO from reverse water gas shift reaction at the reaction temperatures greater that 150 'C. Furthermore, the lower of O2 and CO2 and CO concentrations, the higher of the catalytic activity in the presence of excess hydrogen was. This may due to the availability of active sites.