三元催化剂选型与设计指南  

作　　者：李冬旭 罗联伟 

机构地区：[1]湖南道依茨动力有限公司,长沙410000

出　　处：《科技创新与应用》2024年第31期117-120,共4页Technology Innovation and Application

摘　　要：三元催化剂(TWC)旨在同时催化发动机废气中氮氧化物(NOx)的还原以及一氧化碳(CO)和碳氢化合物(HC)的氧化。理论上,在化学计量空燃比下可以获得最佳性能。然而,由于空气和燃料估计误差以及燃料供给滞后,实现这样的条件是不可行的。为了补偿空燃比(AFR)的固有误差,催化剂配方中添加了储氧成分(OSC),以缓冲不需要的AFR偏差。TWC架构可以为串联封装在一起的(UF)系统,也可以分为两个单独封装的系统,分割将取决于催化剂的体积和性能要求,例如CC+UF架构使TWC元件体积的一部分更靠近排气歧管(更高的温度)以获得更好的催化剂转换性能。Three-way catalysts(TWC)are designed to simultaneously catalyze the reduction of nitrogen oxides(NOx)and the oxidation of carbon monoxide(CO)and hydrocarbons(HC)in engine exhaust.In theory,the best performance can be achieved at stoichiometric air-fuel ratios.However,due to air and fuel estimation errors and fuel supply delays,achieving such conditions is not feasible.In order to compensate for inherent errors in air-fuel ratio(AFR),an oxygen storage component(OSC)is added to the catalyst formulation to buffer unwanted AFR deviations.The TWC architecture can be a series packaged UF system,or it can be divided into two separately packaged systems,and the division will depend on the catalyst volume and performance requirements.For example,the CC+UF architecture brings part of the TWC element volume closer to the exhaust manifold(higher temperatures)for better catalyst conversion performance.

关 键 词：三元催化剂 储氧成分 老化规格 后处理架构 三元催化剂选型 

分 类 号：TQ426[化学工程]