Supported Mn catalysts and the role of different supports in the catalytic oxidation of carbon monoxide

The effects of the carrier and the content of the active species were studied in the carbon monoxide oxidation process. MnOx catalysts supported on ZrO2, CeO2, MgO, SiO2, and Al2O3 were prepared and characterized by XRD, BET-BJH, FE-SEM, EDX, TPR, and CO2-TPD analyses. The relation between the textural properties of the catalysts and the catalytic performance was investigated. The results showed that Mn/CeO2 catalyst despite of its lowest surface area (55.5 m(2)/g) possessed the highest activity among other catalysts. High ability to supply oxygen through the support during the reaction is the most important reason for the proper performance of this catalyst. The investigation of the Mn content indicated that the 20 wt% Mn/CeO2 showed high dispersion, appropriate reducibility and the highest concentration of active sites compared to other catalysts with various Mn contents. The temperature corresponding to 50% of the CO conversion (T-50) was about 142 degrees C, which was 20 degrees C lower than the other samples. In addition, the influence of different parameters including pretreatment condition, feed ratio, and GHSV was examined on the catalytic performance. The results showed that the catalytic stability declined with the incorporation of water vapor and CO2 in the feed mixture. (C) 2018 Elsevier Ltd. All rights reserved.