"The key to the Diesel DeNOx Catalyst technology is the reductant," Marshall said. "Interestingly, it is the diesel fuel that reduces the NOx to nitrogen, a harmless compound that composes about 72 percent of the Earth's atmosphere. The catalyst achieves such high rates of conversion because of its interactions with the hydrocarbons in the diesel fuel. The reduction in NOx emissions comes as a result of its conversion into nitrogen."
Moreover, the Diesel DeNOx Catalyst has increased performance in the presence of water vapors. "That characteristic makes it ideal for use in automotive and truck exhaust systems, where water is always present," Marshall said.
Marshall and Argonne fellow researchers have also found the Diesel DeNOx Catalyst to be economical to make and use. The technology uses inexpensive metals copper and cerium. Using diesel fuel as the reductant eliminates the need for onboard storage of compounds like ammonia or urea that existing technologies use as reductants, he said. Compared to existing technologies, Diesel DeNOx reduces the amount of additional weight a vehicle has to carry, allowing for more efficient use of a vehicle's fuel, Marshall said.
"Furthermore, the ultra-low sulfur diesel fuel that will soon be required for off-road use and is now mandated for on-highway use actually extends the life of the catalyst technology, which is poisoned by the sulfur," Marshall said.
The Diesel DeNOx Catalyst is a low-cost technology given the usable lifetime of the catalyst, which is about 400,000 miles. A typical semi-tractor trailer or shipping and delive
|Contact: Angela Hardin|
DOE/Argonne National Laboratory