SCR of NO by various hydrocarbons is an effective technique for reduction of pollutant emissions by automobiles, under excess oxygen conditions. A study on experimentally observed features of the selective reduction of NO by C3H6 was carried out using a detailed surface reactions model based on NO adsorption and dissociation. C3H6 was the best reducing agent for SCR of NO under lean burn condition. A detailed surface reaction mechanism was proposed for the NO-C3H6-O2 reaction on Pt catalyst. The simulation results compared well with published experimental data. The conversion of NO showed a maximum value at ∼ 290°C. The C3H6 oxidation increased with temperature up to this peak temperature, and then remained constant with further increase in reactor temperature. The increased tendency of oxygen to adsorb on the catalyst sites led to the decrease in NO conversion with an increase in temperature, at temperatures higher than the peak one. This is an abstract of a paper presented at the AIChE Annual Meeting and Fall Showcase (Cincinnati, OH 10/30/2005-11/4/2005).