车用汽油机稀燃催化器NOx排放控制技术

介绍了目前研究较多的吸附还原催化器和选择还原催化器。指出，对于吸附还原催化器，催化器在富氧时储存NOx及在短时间接近当量比的浓混合气燃烧时还原NOx，因此空燃比控制问题至关重要，还需解决硫中毒的问题；对于选择还原催化器，适当增大HC／NOx的比值，对活性金属组成配比及含量进行优化或添加某些氧化物，均可提高NOx转化率。对热稳定性及水蒸气中毒等问题也进行了分析，并讨论了稀燃催化器今后的研究方向。

Control Technology of NOx Emissions of Lean-burn Catalytic Converters for Automotive Gasoline Engines

The absorptive reducing catalytic conve rt er and the selective reducing catalytic converter which are re-searched much mo re recenlty are introduced.It is pointed out that,as to the absorptive cataly tic converter that saves NO x When oxygen is enriched and reducing NO x when the rich mixed gas that approaches the equivalent ratio in short time is burning,so air-fuel ratio control is critical and sulfur poisoning is ano ther problem to be resolved;as to the selective re-ducing catlytic converter, increasing the HC to NO x ratio properly,optimizin g the proportion of active metals and their con-t ents,and adding some oxides can all improve the converting ratio of NO x .The thermal stability,vapor poisoning and etc.are also analyzed.The res earch direction in future of Lean-burn catalytic converter is discussed.