Diesel engines are preferred system over the gasoline, due to their high fuel efficiency, low-operating cost, high durability and low CO2 emission. However, emissions of NOx and soot as well as CO and HCs from diesel engines are major concern due to severe health and environment effects. Further, Euro-6/Euro-VI standards for light duty/heavy duty vehicles are implemented in Sept. 2014 require additional reduction of 56%/80% in NOx and 10%/67% in soot emissions compared to Euro-5/Euro-V levels respectively. Four way catalysts (FWC) seem to be a possible single-component technology solution to control total emissions. In the present work, the double layers of catalysts containing perovskite and Cu-ZSM5 were explored for the same purpose. La0.6K0.4CoO3 catalyst along with Cu-ZSM showed 100% conversion of NOx at 450oC with peak temperature of soot combustion at 420oC, the temperature of the HC total conversion was 480oC, and 100% conversion of CO was at 388oC which are in the range of exhaust temperature of 150¿450 °C. The activity order of double layers catalysts is as follows: La0.6K0.4CoO3 (Sol-gel)+Cu-ZSM-5 > La0.6K0.4CoO3 (Sol-gel) + Ag/Al2O3 > La0.6K0.4CoO3 (Co-ppt)
