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采用共沉淀法制备Ce O2-ZrO2-La2O3-Pr O2-Al2O3复合氧化物载体材料,以浸渍法制备了Pd-Rh,Pt-Rh和Pt-Pd-Rh型整体式催化剂.用N2吸附-脱附、程序升温还原、储氧量和X射线衍射对其进行了表征,并考察了老化前后催化剂的空燃比特性、空速特性和温度特性.结果表明,在三种催化剂中,Pt-Pd-Rh型催化剂表现出更优异的性能.在40000 h-1空速下,新鲜Pt-Pd-Rh型催化剂对C3H8,CO和NO的起燃温度T50分别为239,187和191o C,ΔT(T90-T50)分别为21,3和3o C.老化后,C3H8,CO和NO的T50分别为298,203和223o C,ΔT分别为22,5和13o C,且老化前后空燃比窗口较宽,适合于未来排放标准的摩托车尾气净化.
Pd-Rh, Pt-Rh and Pt-Pd-Rh monolithic catalysts were prepared by coprecipitation method using CeO2-ZrO2-La2O3-PrO2-Al2O3 composite oxide as support. Temperature and reduction, oxygen storage capacity and X-ray diffraction were used to characterize the catalysts.The air-fuel ratio, space velocity and temperature characteristics of the catalysts before and after aging were also investigated.The results showed that among the three catalysts, the Pt-Pd- Rh type catalyst showed more excellent performance.At 4000 h-1 space velocity, the fresh Pt-Pd-Rh catalyst for C3H8, CO and NO light-off temperature T, respectively 239,187 and 191o C, ΔT (T90-T50 ) Were 21, 3 and 3o C. After aging, the T50 of C3H8, CO and NO were 298, 203 and 223o C, respectively, and the ΔTs were 22, 5 and 13o C, respectively. Standard motorcycle exhaust purification.