The Effect of ZrO2 on the Rh/γ-Al2O3 Catalyst for NO Catalytic Reduction

The effect of ZrO2 additives on Rh/γ-Al2O3 was studied.The TPR,XRD,BET surface area and the catalysts activity of NO+C2H4 and NO+C2H4+O2 reactions were measured for the catalysts with variety of crystal phases and doping manners of ZrO2 It is found that the ZrO2 possesses the ability of depressing the interaction between Rh3+ and γ-Al2O3 and retarding the phase transition of γ-Al2O3 to some extent.The reaction activity of NO+C2H4 is pronounced enhanced during ZrO2 doped onto the Rh/γ-Al2O3 after aging at 850℃ in atmosphere for 2h than that of the Rh/γ-Al2O3,while the activity of SCR for the samples is low and the sample containing ZrO2 is lower than that of the Rh/γ-Al2O3.It implicates that the reaction mechanism is quite different between NO+C2H4 and NO+C2H4+O2.The Competitive full oxidation of C2H4 promoting by ZrO2 is suggested.