The Roles of Phosphorus and Soot on the Deactivation of Diesel Oxidation Catalysts

The deactivation of diesel oxidation catalysts (DOCs) by soot contamination and lube-oil derived phosphorus poisoning is investigated. Pt/CeO₂/γ-AI₂O₃ DOCs aged using three different protocols developed by the authors and six high mileage field-returned DOCs of similar formulation are evaluated for THC and CO oxidation performance using a bench-flow reactor. Collectively, these catalysts exhibit a variety of phosphorus and soot morphologies contributing to performance deactivation.