Ammonia Oxidation on Structured Composite Catalysts

The NH₃-based selective catalytic reduction of NO _x on monolithic zeolite catalysts has emerged as the technology of choice for heavy-duty diesel vehicles. A class of Cu-exchanged zeolite catalysts has been developed that have very high ammonia sorption capacity and can achieve high NO _x conversion to N₂ for a variety of transient conditions. In order to fully exploit the latest generation of SCR catalysts, an active, selective and robust post-SCR ammonia conversion system is needed to minimize the breakthrough of ammonia into the environment [1]. The goal of this study is to better understand the steady-state catalytic mechanism of post-SCR ammonia oxidative conversion and product selectivity on low-loading Pt-based catalysts and in so doing provide guidance in the development of a new class of ammonia slip catalysts.