• Ag;
  • Au catalyst;
  • bimetallic nanoparticles;
  • gluconic acid;
  • glucose oxidation;
  • Pt;
  • trimetallic nanoparticles


Polymer-protected metal nanoparticles (NPs) are recognized as a type of complex between a polymer and metal NPs, since the metal NPs are stabilized by coordination to the polymer. Thus, they can work as an effective catalyst in a dispersed state due to their high surface area-to-volume ratio and high stability by protection with poly(N-vinyl-2-pyrrolidone) (PVP). In this study, colloidal dispersions of PVP-protected and Au-containing bi- and trimetallic NPs were prepared and applied to the catalyst for the aerobic oxidation of glucose into gluconic acid in an alkaline solution. The AuAg and AuPt bimetallic NPs were more active than the Au NPs although the Ag and Pt NPs were less active than the Au NPs. The AuAgPt (Au/Ag/Pt = 7/2/1) trimetallic NPs were the most active catalyst for the same reaction. The high activity can be explained by electronic charge transfer from the Ag or Pt to the Au.