The use of gold as a catalyst in diesel emissions systems can reduce smog-forming emissions by up to 40%, according to one company that is using this for its new diesel emissions-reduction product. Nanostellar Inc., a manufacturer of nano-engineered catalyst materials, recently unveiled its Nanostellar's NS Gold catalyst, which enables manufacturers of light- and heavy-duty diesel engines, as well as manufacturers of catalytic converters for diesels, to reduce noxious emissions by as much as 40% more than existing pure-platinum catalysts at equal cost.
Platinum is the most expensive component of the diesel oxidation catalysts (DOCs) that are required to meet the new, stringent emissions regulations for the 14-million light-duty and 2-million heavy-duty diesel vehicles produced annually worldwide. In recent years, Nanostellar and other 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, Nanostellar has implemented the use of gold—which is currently about half the price of platinum—for diesel emissions control.
When compared to emerging platinum-palladium catalysts, NS Gold promises to increase hydrocarbon oxidation activity by 15% to 20% at equal precious-metal cost. A tri-metal formulation of gold, platinum and palladium, NS Gold 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.
NS Gold is potentially suitable for treating all lean-stream exhaust, where air is in excess of fuel-borne hydrocarbon gases. Applications include, but are not limited to, treating particulates and hydrocarbons in soot filters, stationary-source volatile organic compound (VOC) emissions and ammonia slip in selective catalytic reduction (SCR) systems.
"Not only does NS Gold break performance barriers imposed by mixed platinum and palladium catalysts, but also its performance can be more easily tuned to the characteristics of a variety of diesel engines," said Pankaj Dhingra, CEO of Nanostellar. "We are excited to offer NS Gold to improve the cost equation for the diesel industry. Gold is not new to catalyst scientists, but this is the first time it has been successfully adapted for use in automotive diesel oxidation catalysts."
Via: SEMA Press-release
Source: “Nanostellar Introduces Gold in Oxidation Catalyst That Can Reduce Diesel Hydrocarbon Emissions by as Much as 40 Percent More Than Commercial Catalysts,” Nanostellar, Inc.; SEMA Research and Information Center