Advanced Catalyst Technologies with Low Precious Metals for Indian Two Wheeler Applications 2003-26-0022

India, as a major two and three wheeler production center in the world, is also leading with the stringent emission regulations for this segment of the vehicles. Emission legislations were introduced in 1991 and have been progressively tightened since 1996. The present legislations of 2.0 g/km CO, 2.0 g/km HC+ NOx for two wheelers and 4.0 g/km CO, 2.0 g/km HC+NOx for three wheelers, are being considered as the most stringent in the world. In addition, a voluntary emission warranty of 30,000 km by the manufacturers of two and three wheelers and a deterioration factor of 1.2 on the emission norms of the catalyst equipped vehicles, put an additional strain on the catalyst technologies, as well as on the overall vehicle systems.

In order to meet these challenges, and with focus on the cost effective solutions required for developing countries like India, new advanced catalyst technologies have been developed with improved performance and even lower precious metal content.

As already well known in the passenger car applications, Pd/Rh double layered catalyst technologies have been widely in use over the years. Advantages of these technologies are well known. However, due to recent volatility of Pd and Rh prices, low precious metal containing Pt/Rh double layered catalyst technologies have been introduced in many passenger car applications.

These advanced catalyst technologies have been successfully modified and adapted to two and three wheeler vehicles and specific applications are being done in India.

The paper describes the process of development of these technologies, advantages and the applications on Indian two wheelers.

Results including mass emissions with ultra low precious metal loadings are presented on Indian Driving Cycle (IDC) on various 2 stroke / 4 stroke two wheelers. Tests were done with fresh and aged catalysts. Information about aging procedures is also given.