Atomic scale deposition of Pt around Au nanoparticles to achieve much enhanced electrocatalysis of Pt.

We report an electrochemical method to deposit atomic scale Pt on a 5 nm Au nanoparticle (NP) surface in N-saturated 0.5 M HSO. Pt is provided by the Pt wire counter electrode via one-step Pt wire oxidation, dissolution, and deposition realized by controlled electrochemical scanning. Scanning from 0.6-1.0 V (vs. RHE) for 10 000 cycles gives AuPt, which serves as an excellent catalyst for the formic acid oxidation reaction, showing 41 times higher specific activity (20.19 mA cm) and 25 times higher mass activity (10.80 A mg) with much better CO-tolerance and stability than commercial Pt. Our work demonstrates a unique strategy to minimize the use of Pt as a catalyst for electrochemical reactions.