含铂汽车尾气三效催化剂的研究

Catalytic emission removal on the Pt only three-way catalysts

研究了不同负载量的含铂三效汽车尾气催化剂的催化活性 ,结果表明铂的负载量对催化剂的起燃温度影响很大 .经 10 5 0℃老化后 ,在高负载量的铂催化剂上 ,丙烷、丙稀和一氧化碳起燃温度 (T50 )分别为 95℃ ,15 5℃和190℃ ;而在低负载量的铂催化剂上 ,对应的值为 180℃ ,2 10℃和 2 6 5℃ .另一方面 ,添加过渡金属可以显著提高铂催化剂对氮氧化物的还原活性 ,在低负载量的铂催化剂上 ,氮氧化物的起燃温度可达 2 5 0℃ ,这将有助于开发研制非铑贵金属汽车催化剂 ,更有效地降低催化剂的成本 。

Automobile emissions have already been major pollution in metropolitan cities in China. Three-way catalysts(TWC) are very effective to control automobile exhaust emissions. In this paper, Pt containing TWCs have been investigated. The catalytic activity tests show that Pt loading amount affects the light-off temperature significantly. The light-off temperatures of C 3H 8,C 3H 6 and CO on the catalyst containing lower Pt being calcined at 1?050?℃ are 95?℃,155?℃and 190?℃, respectively; while the values are 180?℃, 210?℃ and 265?℃ on the catalyst containing higher Pt. On the other hand, transition metals can significantly improve the NO reduction activities on Pt containing catalysts. The results show that the Pt containing catalysts are potential TWC catalysts with lower cost and high thermal stability.