<b>THE INFLUENCE OF TRANSITION METALS ON THE PERFORMANCE OF Pt Rh Pd/&gamma;-AL₂O₃ THREE WAY CATALYSTS FOR PURIFICATION OF AUTOMOTIVE EXHAUST GAS</b>

Abstract

The influences of transition metal oxides (Zr, Mn, Co, Cu, Mo) on the performance of Pt Rh Pd/γ-Al₂O₃ three way catalysts were studied. The characteristics of the catalysts are investigated by using XRD, TPD, TPR. Experimental results show that the addition of Zr, Mn, Co, and Cu promoters improved the activity of Pt Rh Pd/γ-Al₂O₃ catalyst remarkably for CO, CH and NOx conversion, respectively. The effective order of the promoters is CuO > ZrO₂ > Co₃O₄ > MnO₂. The addition of CuO improved the dispersion of the noble metal on the γ-Al₂O₃ support and increased the absorption of Pt Rh Pd/γ-Al₂O₃ catalyst for CO and O₂, in addition, promoted the reduction of the noble metal.

KEY WORDS: Purification of exhaust gas, Pt Rh Pd/γ-Al₂O₃ catalyst, Transition metals


Bull. Chem. Soc. Ethiop. 2006, 20(1), 113-120.