International Journal of Scientific & Engineering Research, Volume 7, Issue 10, October-2016 1730 ISSN 2229-5518 IJSER © 2016 http://www.ijser.org Total oxidation of CO by CuMnOx catalyst at a low temperature Subhashish Dey 1 , Ganesh Chand Dhal 1 , Ram Prasad 2 , Devendra Mohan 1 1 Department of Civil Engineering, IIT (BHU), Varanasi, India 2 Department of Chemical Engineering and Technology, IIT (BHU), Varanasi, India Abstract— The copper manganese oxides catalyst was synthesized by using co-precipitation method with different Cu:Mn ratio for carbon monoxide oxidation. The drying of the precursor at 120 o C temperatures for 12 h in an oven and calcinations at 300 o C in stagnant air, flowing air and in a reactive gas mixture of 4.5% CO in the air known as reactive calcination (RC). The CuMnOx catalyst is prepared into different molar ratio like (Cu:Mn=2:1), (Cu:Mn=1:1) and (Cu:Mn=1:2) for oxidation of CO. The activity of the catalysts was evaluated in a tubular reactor under the following conditions: 100 mg catalyst, 2.5% CO in air, total flow rate 60 mL/min and temperature varying from ambient to a higher value, at which complete oxidation of CO was achieved. The decomposition of mixed copper and manganese nitrate in controlled conditions therefore produced CuMnOx catalyst and it depending on the oxygen concentration and flow conditions of gases during the heat treatment. The prepared catalysts were characterized by XRD, FTIR, SEM-EDX, XPS and BET techniques. The ability to oxidation state and phase composition of CuMnOx catalysts is a key preparation parameter for controlling the CO oxidation. Index Terms— Carbon monoxide, Catalytic oxidation, Ambient temperature, Hopcalite catalysts, Co-precipitation, Reactive Calcination. ——————————  —————————— 1 INTRODUCTION Air pollution has become a major concern in most of the countries in the world. It is responsible for causing respiratory diseases, cancers and serious other illness. In addition of the health effects, air pollution also contributes to high economic losses. The transportation sector i.e. the vehicles (particularly cars, trucks and buses) which run by petrol and diesel are one of the greatest contributors to air pollution. It was expected that motor vehicles emissions contribute to the global emissions, an amount of 21% for carbon dioxide (CO 2 ), 37% for nitrogen oxides (NOx), 19% for volatile organic compounds, 18% for carbon monoxide (CO) and 14% for black carbon (1). Carbon monoxide with the chemical formula of CO is a colorless, odorless and tasteless, it is highly toxic and it emitted from vehicle exhaust. It is produced from the partial oxidation of carbon-containing materials. It converted in to the more usual carbon dioxide (CO 2 ) when there is a reduced availability of oxygen, such as when operating an internal combustion engine in an enclosed space Carbon monoxide (CO) and carbon dioxide (CO 2 ) from diesel engines are relatively low. The CO emissions are more significant in the spark ignition engines as the fuel/air ratio is often close to stoichiometric at a part of the load and more at full load (2). A catalytic converter is an automobile emissions control device that converts toxic pollutants in the exhaust gas into less poisonous gas by catalyzing a redox reaction (oxidation or reduction). Catalytic converters are used in internal ignition engines fueled by either gasoline or diesel-including lean burn engines. For the catalyst design, it is essential to explain the catalyst performance parameters into a physical picture of the catalyst structure (3). In the beginning more interest has been focused on catalytic control of CO emissions from automobile exhaust because it is dangerous for the environment. On start- up car exhaust catalysts take a little time to become effective and this primarily due to the time required to heat the catalyst using the exothermicity of the combustion reactions. If the catalyst could be added that was very efficient for CO oxidations at lower temperatures then this initial warm-up period could be shortened and the cold start problem can be solved (4). In the last 35 years, the catalytic converters have been installed on more than 1000 million vehicles around the world. The choice of the appropriate catalyst is an important step for improving the environment. The most effective catalysts for CO oxidation at low a temperature in many years are known as hopcalite catalyst (CuMnOx), which is a mixture of copper manganese oxide (5). The catalytic properties of such a system called hopcalite were confirmed by Jones and Taylor in the year 1923; since that time hopcalite has become a well-known oxidation catalyst at room temperature. A literature study reveals that CuMnOx catalyst is extremely active in the amorphous state even at room temperature but it has observed that the CuMnOx catalyst lose his activity after exposition at temperatures above 773K where crystallization of the spinel CuMn 2 O 4 . However, crystalline Cu 2 MnO 4 has also been reported by Schwab and Kanungo (6) to be active. Recently, the low temperature oxidation of carbon monoxide has seen a renaissance in its interest to the catalytic community. Ever since that time, hopcalite catalysts have been employed to oxidize a range of environmentally damaging gasses at low temperatures. A lot of attention has been given to modification of the CuMnOx catalyst in order to remove its faults of moisture for deactivation and low activity. The preparation of the catalyst by other non-conventional methods including synthesis of nano-crystalline copper manganese oxide catalysts by using the supercritical anti-solvent precipitation method (7), copper manganese oxide from sol-gel (8) were reported to give better conversion than commercial hopcalite. IJSER