The role of Pd–Pt Interactions in the Oxidation and Sulfur Resistance of Bimetallic Pd–Pt/γ-Al₂O₃ Diesel Oxidation Catalysts

Diesel oxidation catalysts (DOC) were investigated for activity, NO conversion stability, and sulfur poisoning/regeneration on Pd/Al2O3, Pt/Al2O3, Pd-Pt/Al2O3 catalysts. The Pd/Al2O3 catalyst was more active CO hydrocarbon (C3H6 C3H8) oxidation, while the Pt/Al2O3 efficiently oxidized NO. formation of a Pd-Pt alloy in maintained Pd reduced phase, resulting superior activity this CO, C3H6, comparison with its monometallic counterparts. not only provided low-temperature but also retained stability oxidation. favored spillover SO2 to alumina support, significantly higher adsorption capacity catalyst, extensively prolonging lifetime. However, stable sulfates made it difficult completely regenerate catalyst. bimetallic sample showed C3H8, C3H6 after poisoning regeneration.