First, CO was allowed to adsorb on samples at a flow rate of 15ml/min for 30 min at room temperature. The catalyst was then flushed with nitrogen for 30 min at room temperature to remove the gas phase and weakly adsorbed CO. Finally, the catalyst was heated from 25 °C to 400 °C at a constant heating rate of 10°C/min in the presence of nitrogen and desorbed CO and CO 2 was monitored. For the quantification of Conversion of CO, O 2 and the reaction product, calibration of GC was done. A calibration experiment was performed in which the standard gas mixture (CO, CO 2 , H 2 , N 2 ) was used. 1 ml of this calibration standard gas was injected in GC, and the areas of different peaks of the gases were noted for the known concentration of the gases.