Oxidation catalysts for stoichiometric natural gas engines

摘要

An oxidation catalyst (5) for treating exhaust gas produced by a stoichiometric natural gas (NG) engine comprising a substrate and a catalyst material for oxidizing hydrocarbons (HC), The catalytic material for oxidizing hydrocarbon (HC) comprises a molecular sieve and a platinum group metal (PGM) supported on the molecular sieve, the molecular sieve having a skeleton comprising silicon, oxygen and optionally germanium. Oxidation catalyst. The first zone (2) at the inlet of the catalyst is a zone containing a catalyst material for oxidizing ammonia. At the outlet end of the catalyst is a second region (3) which is a zone containing a catalyst material for oxidizing hydrocarbons. Both the first region and the second region are arranged directly on the substrate (1). The second region (3) containing the catalyst material for oxidizing the hydrocarbon may be a zone disposed on the first layer (2) containing the catalyst material for oxidizing ammonia. [Selection] Figure 2