摘要
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.
A new composite oxide material as support, CeO2-ZrO2-La2O3-PrO2-Al2O3, was synthesized by a co-precipitation method. Pd-Rh, Pt-Rh, and Pt-Pd-Rh supported on monolithic carrier catalysts were obtained by an impregnation route. The textural, structural, and reductive properties of the cata-lysts were characterized by N2 adsorption-desorption, temperature-programmed reduction, oxygen storage capacity measurements, and X-ray diffraction. The air-fuel-ratio （A/F）, space velocity （SV）, and temperature characteristics of the fresh and aged catalysts were investigated on a systematic basis. The results showed that among the three catalysts, Pt-Pd-Rh displayed the best performance. For an SV of 40000 h-1 in the case of fresh Pt-Pd-Rh, the light-off temperatures （T50） for C3H8, CO, and NO were 239, 187, and 191 ℃, respectively, with correspondingΔT （T90-T50） values of 21, 3, and 3 ℃, respectively. After aging, the T50 for C3H8, CO, and NO were 298, 203, and 223 ℃, respec-tively, and theΔT values were 22, 5, and 13 ℃, respectively. Moreover, the window widths for the A/F in the case of fresh and aged Pt-Pd-Rh catalysts were wide. Overall, the excellent performance for the Pt-Pd-Rh catalyst makes it suitable as a motorcycle exhaust catalyst, which can meet future emission standards.
出处
《催化学报》
SCIE
EI
CAS
CSCD
北大核心
2014年第9期1482-1491,共10页
基金
国家自然科学基金(20803049
21173153)~~
关键词
摩托车尾气净化
整体式催化剂
铂-钯-铑
空燃比特性
空速特性
温度特性
Motorcycle exhaust purification
Monolithic catalyst
Pt-Pd-Rh
Air-to-fuel ratio characteristic
Space velocity characteristic
Temperature characteristic
