Aspects of Propane, Isopropylamine and NH3 as Reducing Agent for NOx over H-ZSM-5 in oxygen excess

Introduction Combustion in excess oxygen, as in dieseland lean-burn engines, significantly improves the fuel economy, i.e. reducing the CO2 emissions. However, the lean environment in the exhaust gas obstructs the NOx reduction ability of the three-way catalyst, thus emphasizing the need for alternative techniques, where one promising is selective catalytic reduction with hydrocarbons (HC-SCR). A vast amount of research has been devoted to the mechanisms of this concept. For zeolite materials, three main reaction pathways have been suggested and debated in the literature [1,2]. That is catalytic decomposition of NO to nitrogen, oxidation of NO to NO2, and partial oxidation of the hydrocarbon forming oxygenand/or nitrogencontaining intermediate species.