Nissan Motor said on Friday it had developed a new catalyst for petrol-powered cars that needs only half the precious metals of current catalysts.

The new catalyst will be introduced into production vehicles during the automaker's 2008 financial year.

The new technology developed by the Renault--Nissan Alliance uses "a significantly less amount of precious metal" but performs just as well as existing catalysts.

Petrol-engine catalysts use a mix of platinum, rhodium and palladium and the chemical reaction between the precious metals and exhaust gases contributes to the chemical transformation of nitrogen oxide, carbon monoxide and hydrocarbons into non-toxic compounds such as nitrogen, water and carbon dioxide (CO2).

Nissan said that the high temperatures in current catalysts cause the precious metals to cluster-up, reducing the exposed metal surface area, leading to less effective cleaning of the gases. To compensate for this problem, existing converters contain a higher amount of precious metals in order to maintain an efficient level of cleaning.

Employing nano-technology, the automaker has succeeded in keeping the fine metal particles separated to prevent them from clustering under high temperature conditions. This pioneering technology enables the catalyst to maintain performance while using only half the amount of precious metals needed.

Automakers fret over platinum prices