Nissan Motor Co., Ltd has developed as part of the Renault-Nissan Alliance a new catalyst for petrol cars that uses only half the precious metal components versus conventional catalyst currently available, and will launch it in its cars from fiscal 2008.
The technology results in no changes in the performance of the catalyst. Exhaust-cleaning automotive catalysts comprise a mix of platinum (Pt), rhodium (Rh) and palladium (Pd). Within the catalyst, the chemical reaction between the precious metals and exhaust gases contributes to the chemical reaction of nitrogen oxide (NOX), carbon monoxide (CO) and hydrocarbons (HC) – into non-toxic compounds such as nitrogen (N2), water (H20), and carbon dioxide (CO2).
In conventional catalysts, the high temperatures within the catalyst cause the precious metals to cluster-up, reducing the exposed metal surface area, leading to less effective cleaning of the gases. Existing converters contain a higher amount of precious metals in order to compensate for this attrition. Employing advanced nano-technology, Nissan has succeeded in keeping the fine metal particles separated to prevent them from clustering under high temperature conditions.