The comparative analysis of catalytic properties of Group 11 elements in NOx reduction by hydrocarbons in the presence of oxygen

NOx emission reduction in diesel engines can be achieved by using catalytic reactors reducing nitrogen oxides, including NH3-SCR and possibly also HC-SCR reactors. Reactors using ammonia achieve large conversion rates but cause a lot of operational problems. For this reason, the interest in reactors using hydrocarbons and their derivatives to reduce NOx has increased. Such reactors are the ones using metals from Group 11 (coinage metals) such as Cu, Ag and Au placed on an Al2O3-SiO2 carrier as active materials. The article characterizes the porosity and acidity of the carrier surface. Conversion of NO2, NO and propene as well as the formation of CO and N2O depending on the temperature at constant dosing of propene on a carrier covered with Cu, Ag and Au with a metal content of 4 g/dm3 were evaluated. The results of the tests showed that the tested Group 11 elements can be the basis for further experiments related to the development of this exhaust fumes cleaning technology for diesel engines.