An exploratory study on simultaneous removal of soot and NOx over Ir/γ-Al2O3 catalyst in the presence of O2

The potentiality of Ir/γ-Al2O3 catalyst for the simultaneous removal of soot and NOx in the presence of O2 has been investigated by using temperature programmed reaction (TPR) technique. Ir/γ-Al2O3 exhibits a high activity. The simultaneous removal paths are that the NO2 formation by the oxidation of NO promotes the soot oxidation and the CO formation by the soot oxidation reduces NO. Furthermore, the adsorbed–dissociation of NO2 also promotes the NOx reduction. The comparison between Ir/γ-Al2O3 and Pt/γ-Al2O3 reveals that Ir/γ-Al2O3 is a more effective catalyst for the simultaneous removal of soot and NOx.