New Perovskite based Catalytic Converter using Metallic Substrate 990006
Non-noble metal based catalysts offer a cost-effective substitute for commonly used noble metal automotive catalysts. Perovskite type catalyst compositions are again becoming attractive mainly due to their low-cost, higher thermal stability, resistance towards poisoning species and a great degree of flexibility in the composition and structure for their possible tailoring to meet the specific catalytic requirements. However, catalytic activity and light-off characteristics of these catalysts are often reported to be comparatively inferior, which has ultimately limited their applications, particularly in respect of stringent emission norms with cold-start test procedures. Some new perovskite based catalyst compositions have been studied using alumina washcoated metallic substrates. These catalysts show excellent thermal stability, and there light-off characteristics have been remarkably improved by properly using metallic substrates. Modified alumina washcoated process has been developed to improve the surface area of perovskite catalysts coated supports. This has resulted in improved performance and practical feasibility of such non-noble metal based converters. The present paper deals with the detailed laboratory and dynamometer studies on new perovskite catalysts based converter, improved by application of suitable alumina washcoat and metallic substrates.