Preparation of Pt/Al2O3 and PtPd/Al2O3 catalysts by supercritical deposition and their performance for oxidation of nitric oxide and propene

Pt/Al2O3 and bimetallic PtPd/Al2O3 catalysts were prepared via supercritical deposition method using carbon dioxide. The effects of Pt loading Pd addition to on particle size, size distribution (PSD) activity for NO C3H6 oxidation C3H6-selective catalytic reduction (C3H6-SCR) investigated. with loadings 0.6, 1.2 2.1 wt% a catalyst was total metal 1.4 Pt:Pd molar ratio 1.3:1. A small fraction the particles agglomerated after calcination at 550 °C. Around 98 % had an average ?1 nm. rest larger these ?10 nm monometallic ?6.5 PtPd/Al2O3. All found be active C3H6-SCR reactions. performance highest. increased increasing content. Light-off temperature shifted higher in presence NO, suggesting competitive NO. Concentration profiles indicated that started when conversion by reached 50 %; consumed both conversions.