Catalyst for purifying diesel engines exhaust gases and process for its preparation

摘要

A diesel engine gas catalyst has a zeolite with aluminum oxide or silicon dioxide, or titanium dioxide, or zirconium dioxide and aluminum silicate. The catalyst also has either platinum or rhodium and iridium. The noble metal has a median oxidation level of +2.5, with more than 3 metal ligands, and less than three oxygen ligands. Crystalline substances of average particle size 1-6 nm are present on the surface of the zeolite and substrate oxides. An Independent claim is also included for the production of the diesel exhaust catalytic converter. The ratio of the substrate oxide to the zeolite is 10:1-2:1. The mass ratio of the noble metal on the zeolite to the noble metals on the substrate oxide is 1:100-1:10. The noble metals are present in a concentration of 0.05-10 wt.% w.r.t the overall weight of the catalyst.