Engineering the Near‐Surface of PtRu3 Nanoparticles to Improve Hydrogen Oxidation Activity in Alkaline Electrolyte

Tailoring the near‐surface composition of Pt‐based alloy can optimize the surface chemical properties of a nanocatalyst and further improve the sluggish H2 electrooxidation performance in an alkaline electrolyte. However, the construction of alloy nanomaterials with a precise near‐surface composition and smaller particle size still needs to overcome huge obstacles. Herein, ultra‐small PtRu3 binary nanoparticles ( Pt‐increased > Pt/PC. From the perspective of engineering a near‐surface structure, this study may open up a new route for the development of high‐efficiency electrocatalysts with a strong electronic effect and oxophilic effect. PtRu3/PC nanocatalysts with the same bulk composition and a different near‐surface atomic composition have been successfully synthesized via a controlled thermal treatment method. The Ru‐increased nanocatalyst with the strongest electronic effect and oxophilic effect exhibits up to 38.8‐fold and 9.2‐fold HOR improvement in mass activity and exchange current density, compared with the Pt/PC counterpart, respectively.