Low Sulfate Generation Diesel Oxidation Catalyst

Sulfate generation by diesel oxidation catalysts (DOC) is still a problem although sulfur concentration in the diesel fuel will be reduced in future. Two approaches were attempted to reduce the sulfate generation without inhibiting the HC and CO oxidation performance. One was to use an optimized support material that adsorbs less SO₂ and has sufficient specific surface area for HC/CO oxidation. Another approach was to apply a layer on the catalyst, which prevents SO₂ adsorption. Sulfate generation was successfully reduced while maintaining high HC/CO oxidation performance.