Three Way Electrically Heated Catalysts (TWEHC) with capability of on board diagnostics
Adequate know-how has been obtained on the following items regarding the novel TWEHC: 1) Formulation of Pd/perovskite active phases and ways of tailoring their properties. The catalysts based on these formulations exhibit comparable light-off and 3-way efficiency with commercial exhaust catalysts. Their catalytic activity is due to strong synergism between the two components. 2) A simple method has been developed for preparing and coating the active phases with adequate adhesion, conductance and activity. Future improvements in the coating quality are considerd. 3) The novel catalysts exhibit multi-function features in exhaust emissions control: 3a) Operation as light-off or main 3-way catalysts. Under-floor or close-coupled operation positions are assessed to be feasible. An intermediate operation position offers advantages with respect to 3-way performance, SO2 resistance and lifetime. 3b) Operation as effective Electrically Heated Catalysts with very low electrical power consumption. This is due to selective heating of the active phase (i.e. current passage through the active phase only). 3c) Effective and relatively simple diagnosis of the light-off characteristics through monitoring of the relative conductance change during cold-start. 4d) Potential multi-fuel use (e.g. gasoline and natural gas). Selective active phase heating can be considered for lowering the light-off temperature of methane. Introduction of these catalysts into the market is estimated to result in a significant reduction of the exhaust aftertreatment cost. This is due to increased durability of the catalyst, due to reduced amount of noble metals, and also because of integration and simplicity of the aftertreatment and diagnosis system. This cost reduction is expected to compensate for any cost increase because of the stricter environmental regulations. The benefit of car, catalyst and automotive component manufacturers from such a development is obvious.
Nikos MOSCHOUDIS, (Research associate)
Record Number: 21973 / Last updated on: 2001-07-06
Collaboration sought: Joint venture agreement, Financial support, Further research or development support, Information exchange/Training
Stage of development: Experimental development stage (laboratory prototype), Prototype/demonstrator available for testing