| abstract |
The present invention relates to diesel oxidation catalyst compositions and catalyst articles, wherein the compositions and articles include a plurality of platinum group nanoparticles substantially in fully reduced form, wherein the nanoparticles have an average particle size of about 1 to about 10 nm and at least about 90% of the nanoparticles have a particle size of +/- about 2 nm of the average particle size. Such compositions can further include a refractory metal oxide material, wherein the nanoparticles and refractory metal oxide material can be combined within the same coating on a substrate or can be applied sequentially on a substrate. The nanoparticles can advantageously be substantially free of halides, alkali metals, alkaline earth metals, sulfur compounds, and boron compounds. Methods of preparing and using such compositions and catalyst articles (e.g., for the treatment of diesel exhaust gas streams) are also provided herein. |