三效催化转化器催化剂硫中毒机理

Sulfur poisoning mechanism of three way catalytic converter

在一种详细的表面反应机理中加入了包含贵金属催化剂与助催化剂的硫中毒基元反应,建立了新的三效催化转化器催化反应机理。利用该机理进行了稳态工况数值模拟,得到了各排气污染物起燃温度与转化效率随尾气中SO2浓度的变化情况。采用灰色关联分析了SO2浓度与各排气组分转化效率的关联度,结果表明,SO2浓度对C3H6与NOx转化效率影响最大。对三效催化转化器的催化剂活性设计具有重要的参考价值,并对其工况设计及优化提供了指导。

Combining a detailed catalytic surface reaction mechanism with noble metal and promoter elementary reactions,a new three way catalytic reaction mechanism was established.Based on the new mechanism,steady condition numerical simulation was carried out,and the change of light off temperatures and conversion efficiency with various SO2 contents was gotten.By grey relational analysis,the relational grade between conversion efficiency and SO2 content was gotten.And,the result showed that SO2 content was the most important influence on C3H6 and NOx conversion efficiency.This provides an important reference to the improvement of activity design of TWC,and may provide guidance for the condition design and optimization of a catalytic converter.