催化转化器的研究进展

Research Rrogress of Catalytic Converters

随着国家对环保问题重视程度的提高,对车辆废气排放要求也相应地增加.结合摩托车尾气排放问题,对催化转化器在降低CO、HC和NOX等方面发挥的作用进行了介绍,详细阐述了催化转化器的定义、组成和反应原理,论述了在一定范围内贵金属组分铂、钯、铑的含量越大,催化效率越高,同时其催化活性与贵金属铂、钯、铑的粒径也成线性关系;催化转化器载体孔壁厚度越薄和孔密度越大催化效率越高;汽油品质越好,含硫量越低,催化效率越高;根据不同车型的排放要求,选择合适的温度、排气系统空燃比,使其达到最佳的排放效果.

With the improvement of national emphasis on the environmental issues,the requirements for vehicle exhaust emissions also increases. In this paper,combining with the motorcycle exhaust emission problems,the roles of catalytic converter plays in reducing emissions of CO,HC and NOX,etc were introduced,and the composition and principle of the catalytic converter were discussed in detail. It＇s said that the greater the component content of the platinum,palladium and rhodium,the higher the efficiency is. Meanwhile,relationship between the catalytic activity and the particle size of noble metals such as platinum,palladium and rhodium is also linear. The thinner wall thickness is and the greater the hole density is,so the higher the catalytic efficiency is. The catalytic efficiency will increase with the improving of the quality of gasoline and the decline of the sulfur content. According to the emission requirements of different models,the catalytic converters will achieve the best emission effect by selecting the appropriate temperature and air fuel ratio of the exhaust system.