Posted: April 18, 2007

Gold nanoparticle catalyst reduces diesel emissions

(Nanowerk News) Platinum is the most expensive component of the diesel oxidation catalysts (DOCs) that are required to meet the new, stringent emission regulations for the 14 million light-duty and 2 million heavy-duty diesel vehicles produced annually worldwide.
In recent years, producers of catalyst materials have introduced the use of palladium to partially replace the four-times more expensive platinum. Now, to further reduce the amount of platinum needed and the overall cost of the catalysts, one catalyst producer, Nanostellar, has pioneered the use of gold – which is currently about half the price of platinum – for diesel emission control.
Independent testing of Nanostellar’s NS Gold™, in comparison with today’s pure-platinum catalysts, has shown that the gold catalyst increases hydrocarbon oxidation activity by as much as 40 percent at equal precious-metal cost. When compared to emerging platinum-palladium catalysts, gold promises to increase hydrocarbon oxidation activity by 15-20 percent at equal precious-metal cost.
A tri-metal formulation of gold, platinum, and palladium, the new catalyst material allows the proportions of each metal to be adjusted to help catalyst systems engineers meet engine-specific performance targets and stabilize the overall cost of diesel catalysts, despite fluctuations in the price of precious metals.
Source: Nanostellar