Preparation of manganese-impregnated alumina-pillared bentonite, characterization and catalytic oxidation of CO

Al-pillared clays from local available bentonite were synthesized via two methods by the application of conventional and ultrasonic treatments during the intercalation stage. The results of XRD and N2 adsorption indicated an increase in the basal spacing, the specific BET surface area, and porosity subsequent to pillaring by both methods with a considerable shortening of the intercalation process for the ultrasonic method. Al-pillared bentonites were used as supports to prepare manganese oxide catalysts by the wet impregnation of 2 and 10 wt% of Mn. The presence of MnO2 and Mn2O3 were detected by X-ray diffraction and confirmed by temperature-programmed reduction for the higher loading catalyst with 10 wt% of Mn. The catalytic activity of our catalysts was evaluated in the CO oxidation reaction. According to our results, the concentration of the Mn seems to be the factor that decisively affects the catalytic activity at the expense of the preparation method.