Fabrication of Automotive Catalytic converter based on Perovskite catalysts

Abstract

Automobile tire out pollution contributes appreciably to the air pollution. With fast increasing vehicle massive amount of obnoxious emissions like CO, HC, NOx and particulate matter are resulted. These pollutants have harmful effects on environment and human health. Out of various technologies available for automobile exhaust emission control, a catalytic converter is found to be the best option to control the CO, HC, and NOx emissions from petrol driven vehicles. Catalytic converter is use to convert the toxic emissions of gases SOx, NOx, CO and particulate matters that emits from the vehicles to less poisonous gases like N2, CO2 by reduction and oxidizing the exhaust, as both oxidation and reduction is carried out simultaneously so this converter works on Redox reaction principle, the most efficient catalyst that is carried out both the process is Perovskite catalyst, this catalyst is prepared by conventional methods such as Solgel, Citrate, Co- precipitation but these methods produce low specific surface area Pervoskite, they are complicated and relatively less expensive to put in to practice. To overcome the limitations of above conventional methods a high energy planetary ball mill reactive grinding method is used. The surface area provide by the reactive grinding is more and it does not effect the environment so it is use for making slurry for wash coating the metallic and ceramic monolith by dip coating technique using zirconium oxide and Lanthanum oxide as a primer. In the present study, Pervoskite catalyst (LaCoO3, LaFe0.955 Pd0.04503 and LaFe0.79Co0.18 Pd0.03003) were prepared by citrate complexation, Sol-gel, Co- precipitation and Reactive grinding methods. Prepared Catalysts were characterized by various characterization techniques such as XRD and Particle size analysis. The catalytic performance of the pervoskite for automotive CO oxidation was carried out using atmospheric gas-solid fixed bed reactor with simulated gas mixture containing 1% CO, 1%O2 and balance N2 This project deals with the Fabrication of monolith both metallic and ceramic. Wash coating is performed on the metallic sheet (Stainless steel) to increase the catalytic activity by increasing the dispersion rate of catalyst on the catalyst support ,various slurry is prepared by different methods and using different additives using the Perovskite , it is noted that satisfactory amount of coating is obtained by using primer La203,and additive zirconium nitrate using pervoskite catalyst obtained by Co-precipitation method & Reactive grinding method and its characterization is carried out , further the metallic monolith is Fabricated using flat and Corrugated stainless steel sheets of 0.3mm is washcoated using the slurry prepared by the above mentioned procedure by dip coating technique . Washcoated metallic monolith is installed in the fabricated converter and the conversion rates of Automotive exhaust is checked by installing in vehicles.