Emission Control Through Cu-Exchanged X-Zeolite Catalysts: Experimental Studies and Theoretical Modeling

Abstract

Catalysts based on X-zeolite have been developed by exchanging its Na+ ion with Copper ions and its effectiveness in reducing NOx in an actual SI engine exhaust has been tested. Unlike noble metals, the doped X-zeolite catalysts, studied here, exhibit significant NOx reduction for a wide λ range and exhibit a slow rate of decrease with increase in λ ratio. Back pressure developed across the catalyst bed was found to be well-affordable and power loss due to back pressure is only minimal. During 30 hours of testing of the catalyst, no significant deactivation was observed. Additionally a mathematical model has been developed to predict the performance of the catalyst and to validate that against experimental results. Results predicted by the mathematical model agree well with the experimental results and absolute average deviation of experimental conversion efficiency is found to be less than 5 percent of the predicted value. [S0742-4795(00)01601-X]