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