Oxygen reduction reaction of Pt–In alloy: Combined theoretical and experimental investigations

• The adsorption of O atoms on Pt–In alloys model surfaces was investigated by DFT.
• The improvement of catalytic activity toward ORR was predicted by DFT.
• Pt-10 at% In alloy was synthesized on glassy carbon disk surface.
• By voltammetry on RDE improvement of activity toward ORR was evidenced.

By means of the density functional theory (DFT) calculations, using the adsorption energy of oxygen on single crystal surfaces as criterion, it was predicted that the alloying of Pt with In should improve kinetics of oxygen reduction reaction (ORR). To prove this, the Pt–In alloy having nominal composition Pt9In was synthesized by heating H2PtCl6–InCl3 mixture in hydrogen stream. The XRD characterization confirmed that Pt–In alloy was formed. The electrochemical measurements by rotating disk technique in alkaline 0.1 mol dm−3 KOH solution evidenced faster ORR kinetics for factor 2.6 relative to the one on pure platinum. This offers the possibility of searching for new ORR electrocatalysts by alloying platinum with p-elements.

Upon DFT prediction of improved electrocatalytic activity of Pt–In alloys toward ORR, the alloy Pt-10 at% In was synthesized on glassy carbon disc, simultaneously with pure Pt reference catalyst. Improved catalytic activity of the alloy was evidenced by voltammetry on RDE in 0.1 mol dm−3 KOH solution.Figure optionsDownload as PowerPoint slide