Improved catalytic converters for selective catalytic reduction

为了满足政府严格的汽车排放目标和提高燃油经济性，稀燃发动机的使用引起了极大的兴趣，无论是柴油、汽油还是天然气。在这种环境下，控制排放，特别是氮氧化物的排放是具有挑战性的，通常使用选择性催化还原(SCR)来实现。在这个反应中，氨被注入废气中，然后废气与氮氧化物催化反应生成氮气。已经使用了几种催化剂，但它们在水存在时存在过度失活的问题。正在开发的最新催化剂是基于铜钙钛矿的。由于它们相对较新，没有太多信息可以用来对反应堆进行计算机建模，而反应堆是开发新转换器的一个越来越重要的工具。

To meet strict government mandated automotive emission targets and improved fuel economy, there is great interest in the use of lean burn engines, either Diesel, gasoline or natural gas. Control of emissions, especially oxides of nitrogen, is challenging in this environment, and is usually achieved using selective catalytic reduction (SCR). In this reaction, ammonia is injected into the exhaust, which then catalytically reacts with NOX to produce nitrogen. Several catalysts have been used, but they suffer from excessive deactivation in the presence of water. The newest catalyst being exploited is based on copper chabazite. Because of their relative newness, there is not much information available that allows for the computer modelling of the reactor, which is an increasingly important tool used in the development of new converters.