A Non-Noble Metal Based Catalytic Converter for Two-Stroke, Two-Wheeler Applications

Two wheelers constitute almost three fourths of the vehicular population in developing countries like India, and consequently they are the major contributors to vehicular pollution. Catalytic converters based on non-noble metal catalyst have been developed for 2-stroke, 2-wheelers application. In this study a modified and thermally stable alumina washcoat has been developed for application of non-noble metal catalyst. Alumina washcoat has been used on both ceramic and metallic honeycomb substrates and subsequently the perovskite type of catalyst has been synthesized in-situ on alumina washcoated substrates. Extensive characterization was carried out during development of alumina washcoat and synthesis of perovskite catalyst to establish the thermal stability of alumina washcoat and phase formation of catalysts. A number of prototypes based on alumina supported perovskite have been prepared and tested for mass conversion efficiency with respect to CO, HC and NOx. The results reveal the confirmation of performance of converter for EURO-I emission norms, which are presently applicable in India for 2-stroke, 2-wheelers. The optimized design of converter minimizes the pressure drop across the converter and the power loss of the engine is well within tolerable limits.