PLATINUM-CONTAINING CATALYSTS FOR COMBUSTION ENGINES

Emissions treatment systems of combustion engines are provided, which comprise a platinum-containing catalyst that is degreened during production, which is before exposure to operating conditions of a vehicle having a diesel engine. The platinum-containing catalyst, in the form of a platinum component on a high surface area refractory metal oxide support, exhibits a vibration frequency of about 2085 to about 2105 cm-1 as measured by CO-DRIFTS. Such catalytic material is essentially-free of platinum oxide species found at greater than about 2110 cm-1 as measured by CO-DRIFTS. Such catalysts can provide excellent and consistent conversion of nitrogen oxide (NO) to nitrogen dioxide (NO2).