【摘要】 采用浸渍法制备了一系列低Pt、Rh含量的Pt-Rh型汽车尾气净化催化剂。研究了在Pt、Rh含量一定以及其他条件不变的情况下,只改变铑在不同载体上的分配比对催化剂性能的影响,测定了催化剂对C3H8、CO、NO的起燃温度,并对催化剂样品进行了程序升温还原(H2-TPR)、程序升温脱附(O2-TPD)表征。结果表明:新鲜催化剂对C3H8、CO、NO的起燃温度相差不大,但经过1000℃、5h的水热老化后,催化剂性能发生了显著的变化,C3H8、CO、NO的起燃温度出现较大的差异,说明了铑在不同载体上的分配比对催化剂性能有一定影响,特别是对催化剂的抗老化性能影响较大。更多还原

【Abstract】 A series of low Pt-Rh catalysts for automobile exhaust purification was prepared by dipping method.The effect of distribution ratio of Rh on two different supports on catalytic per-formance of the low Pt-Rh three way catalysts was investigated and the light-off temperatures of hydrocarbon and carbon monoxide and nitrogen oxides were measured.The catalysts were characterized by means of the temperature-programmed reduction(TPR) and the temperature-programmed desorption(TPD).The results of the test showed that the light-off temperatures of hydrocarbon and carbon monoxide and nitrogen oxides have little difference for the fresh catalysts,but for the catalysts treated by the hydrothermal-ageing for 5 hours at 1000℃ the great differences in the light-off temperature are observed.The best ratio of Rh on different supports can improve the property of the catalysts,specially,the anti-aging property.更多还原