The distinct reaction mechanisms of CuMnOx catalyst with CO has been discussed below. In the CO oxidation process, the oxygen is first adsorbed on the CuMnOx surface with the energy of activation [13]. When the temperature is high an adequate amount so that the adsorption of oxygen reaches enough proportions, therefore any CO passing over the catalyst surfaces either react directly with the adsorbed oxygen or else is first adsorbed and then reacts, after which the CO produced being desorbed [20]. The Cu-oxide is found poorly active for CO oxidation, but in conjunction with Mn-oxide in appropriate proportions, some very active catalyst system is generated [26]. It has been reported that these catalysts’ high catalytic…show more content… The amount of each precursor taken in the reactor was equivalent to 100 mg of the catalyst. The reactor was placed vertically in a split open microprocessor temperature controlled furnace. The heating rate of the bed was 2°C min−1 with a temperature control of ±0.5°C. Reactive calcination of the precursors was carried out by the introduction of a low concentration of chemically reactive CO–Air mixture (4.6% CO) at a total flow rate of 32.5 ml min−1 over the hot precursors. Digital gas flow meters were used to measure the flow rates of CO and air to feed the mixture (dried and CO2 free) in the required proportion into the reactor. A thermocouple placed in the thermo-well of the reactor in contact with the precursor bed measured the temperature of the bed. The temperature of the bed was increased from room temperature to 160°C where CO conversion started. This temperature was maintained for a defined period of time and the CO concentration was measured in the exit stream of the reactor at regular intervals until 100% CO conversion was achieved. After achieving total CO conversion the resultant catalyst was annealed for half an hour at the same temperature then the temperature was increased to 300oC and upheld for an hour followed by cooling to room temperature in the same environment. For the comparative studies catalysts were also prepared by usual calcination of the various precursors in the air at 300o C for an hour. The nomenclature of the resulting unsupported catalysts thus formed is given by the first capital letter of the corresponding precursors used and the suffixes ‘SA’, ‘FA’ and ‘RC’ denote whether they are obtained by calcination in air, flowing air or by RC respectively, as presented in Table