Catalytic oxidation of CO in presence of ozone over supported palladium catalysts

Palladium supported Al2O3 and SiO2 catalysts have been synthesized and evaluated for carbon monoxide oxidation in the presence of ozone. The factors affecting the CO oxidation such as Pd loading (wt%), contact time, reaction temperature and O3/CO molar ratio have been studied. The extent of ozone decomposition on Pd catalysts is proportional to the CO oxidation activity. High reaction temperature or high Pd loading results in the high catalytic activity for CO oxidation. CO chemisorption study shows maximum CO uptake at higher Pd loading. XRD, CO chemisorption and TEM results show that Pd disperses better on alumina than on silica support. The physicochemical properties are well correlated with catalytic activity data. The ozone decomposition on palladium is responsible for the low temperature the CO oxidation. The CO oxidation follows Langmuir Hinshelwood (surface) and Eley-Rideal (surface CO and gas phase ozone) type mixed mechanisms in presence of ozone. The catalytic activity and stability have been tested for 60 hours.