An oxidation catalyst of non-stoichiometric perovskite oxide for the oxidation of no to no2 in an exhaust gas aftertreatment system and method

摘要

A method for the oxidation of no to no₂ in an exhaust gas aftertreatment system for a motor which is operated with hydrocarbon, comprising:(a) supplying a mixture of air and fuel to a motor which is operated with hydrocarbon, wherein the mixture of air and fuel through an air - fuel - mass ratio is defined, which is more than stoichiometric,(b) combustion of the mixture of air and fuel in the motor which is operated with hydrocarbon with the generation of exhaust gas flow (12), one of the no_X-Content, wherein the no_X-Content of no and no₂ in a molar ratio of no to no₂ , and(c) exposing of the exhaust gas flow (12) of an oxidation catalyst with an activity for the oxidation of no to no₂, which is sufficient to ensure that the molar ratio of no to no₂ of the no_X-Content of the exhaust gas flow (12) so as to reduce the oxidation catalytic converter from particles of a perovskite oxide having the formula la.sub.2_XMno_Y in the x in the range from 0,85 – 0,95, and in a load of 5 – 200 g / l of the volume flow rate by means of the particles consisting of la_XMno_Y-Perovskite oxide are present,characterized in thatit is a question of non-stoichiometric perovskite oxide is,Y in the range from 3,19 – 3,30, andthe particles of non-stoichiometric la_XMno_Y-Perovskite oxide have a diameter in the range from 10 nm – 100 μm is.