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Diesel catalyst gets EPA nod

Diesel oxidation catalysts gets EPA verification

Johnson Matthey's Environmental Catalysts and Technologies group has announced that the U.S. Environmental Protection Agency (EPA) has extended the verification of their diesel oxidation catalyst (DOC) to include on-road engines manufactured for 1991 through 2003 model years. Sold under the trade names CEM and DCC, Johnson Matthey said its DOCs are verified for use with on-highway diesel fuels that have less than 500-ppm sulfur content.

According to Malvern, PA-based Johnson Matthey, its DOCs are verified to reduce particulate matter (PM) by 20%, HC by 50% and CO by 40%. The company stated they are "ideal for use in areas that do not yet have access to ultra low sulfur diesel (ULSD) fuel."

The DOCs use a platinum-based catalyst along with a proprietary component to minimize sulfate formation during operation with regular, on-road diesel fuel. However, when applied in conjunction with a ULSD fuel conversion, the combined application can attain a 30% PM reduction over the original engine standards, said the company.

Johnson Matthey pointed out that this verification extension "covers more of the older, higher- polluting diesel engines that will remain in use for many years to come."

Details are listed in an EPA verification letter, and are available on the firm's web site, The verification will be posted on the EPA's official verification website

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