摘要
柴油车尾气污染物主要有碳氢化合物(HC)、二氧化硫(SO_(2))、一氧化碳(CO)、烟尘和氮氧化物(NO_(x)),随着发动机工况的变化,尾气的组成也会发生变化。柴油车尾气中氧气含量较高,所以HC和CO的排放量较少,颗粒物和NO_(x)是最主要的污染物。控制柴油车尾气中NO_(x)的排放是机动车尾气治理的重要一环,开发具有更好性能的选择性催化还原(SCR)催化剂,可以有效应对NO_(x)造成的大气污染。介绍了NH_(3)-SCR技术治理柴油车尾气的原理,归纳了目前柴油车车用NH_(3)-SCR催化剂的特点和主要问题。通过催化剂活性组分调配、元素掺杂、改性等方法提高催化剂的脱硝性能。研发具有较高的低温活性、高温稳定性,且成本较低的催化剂,仍是当前研究的主要方向。
The exhaust pollutants of diesel vehicles mainly include hydrocarbons(HC),sulfur dioxide(SO_(2)),carbon monoxide(CO),soot particles,and nitrogen oxides(NO_(x)).The composition of the exhaust gas varies with the engine conditions changes.The oxygen content of diesel exhaust is relatively high,so the emissions of hydrocarbons and carbon monoxide are relatively low,and soot particles and nitrogen oxides are the main components.It is important to control the emission of nitrogen oxides(NO_(x))from diesel vehicles.Developing selective catalytic reduction(SCR)catalysts with better performance can effectively address atmospheric pollution caused by NO_(x).This paper introduced the principle of selective catalytic reduction of NO_(x) by ammonia(NH_(3)-SCR),summarized the characteristics and main problems of NH_(3)-SCR catalysts currently used in diesel vehicles.The methods were summarized to improve the denitrification performance of the catalyst through the blending of active components,element doping,and modification.Efforts are still needed to develop catalysts with high low-temperature activity,high temperature stability,and low cost.
作者
郑乐辰
李祥如
王靖霏
訾学红
宋丽云
何洪
ZHENG Le-chen;LI Xiang-ru;WANG Jing-fei;ZI Xue-hong;SONG Li-yun;HE Hong(The Faculty of Environment and Life,Beijing University of Technology,Beijing 100124,China)
出处
《化学试剂》
CAS
北大核心
2023年第11期88-97,共10页
Chemical Reagents
基金
国家重点研发计划项目(2022YFB3506200)。
关键词
柴油车
选择性催化还原
脱硝催化剂
NO_(x)排放
尾气治理
diesel vehicle
selective catalytic reduction
denitration catalyst
NO_(x)emissions
vehicle emission control
