摘要：

A new system, designed specifically for diesel engines, composed of a NOx adsorbent trap coupled to a lean NOx reduction catalyst is described. The trap adsorbs NOx between 150 and 500 degrees C which is periodically desorbed thermally by a localized exotherm generated within the catalyst from the controlled injection and oxidation of diesel fuel (always maintaining the exhaust lean). The hydrocarbon injection temperature is controlled to allow for a downstream lean-NOx Pt catalyst to reduce the desorbed NOx. Significant increases in NOx reduction are possible. The trap has good thermal stability but suffers from deactivation by sulfur oxides.

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