Development of Catalysts for Two-Stroke Engines

The Emission Regulations for Motorcycles in Japan was put into effect in October 1998 with the goal of reducing the total hydrocarbon emissions from motorcycles in the country to around 50% of the present amount.

These regulations initiated a need to develop emission-converting catalysts, having the three characteristics written below, for two-stroke engines that historically have produced more hydrocarbons than four-stroke engines:

1. 1
   High performance of hydrocarbon conversion
2. 2
   High light-off performance
3. 3
   High thermal stability under high temperature

Among a number of catalytic adjustment methods, the loading method of precious metals and the washcoat preparing method were modified to realize mass production of high-performance, low-cost catalysts.