Pt or Pd-doped Au/SnO2 Catalysts: High Activity for Low-temperature CO Oxidation.

yAu/SnO₂ ( y = 1–5 wt%) and 1 wt% Pt- or Pd-doped 3Au/SnO₂ catalysts were prepared by the co-precipitation method. It is observed that the 3Au/SnO₂ catalyst showed the best performance ( T_100% = 166 °C). The pretreatment of 3Au/SnO₂ in CO obviously decreased the catalytic activity due to the reduction of oxidized gold species to metallic Au⁰. Pd- or Pt-doping to 3Au/SnO₂ brought about a significant enhancement in performance, with the T_100% value being 74 and 93 °C, respectively. It is concluded that the oxidized gold species were more active than metallic Au⁰ and the remarkable improvement in catalytic activity due to Pd or Pt doping was associated with the presence of strong interaction of Pd or Pt with Au. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]