The metals used in catalytic converters are primarily platinum and rhodium, and automotive applications account for high percentages of the world's reserves of these precious metals (some 50 and 80 percent, respectively). Nissan has decreased the amounts of these metals used in its new catalytic converters by reducing metal clustering, a side effect of high temperatures that requires more amounts of precious metals in order for them to catalyze exhaust gases properly.
The end result: 75 percent less NOx and non-methane hydrocarbons emitted from the exhaust stream of the next-generation Nissan Cube, representing fewer emissions than the 2005 Japanese standards call for. The catalyst technology was co-developed with Renault as apart of the Renault-Nissan alliance. Future applications include Renault vehicles and diesel engines.--Colin Mathews