Electrocatalytic properties of platinum overgrown on various shapes of gold nanocrystals

Electrocatalytic properties of platinum layers overgrown on cubic, octahedral, and spherical gold nanocrystals were investigated. Electrochemically active surface area per unit mass of platinum was significantly different, depending on the shape of gold core nanocrystal. CO stripping results showed that binding of surface platinum atoms to CO was stronger than Pt black when platinum partially covered the gold surface. Au core@Pt shell composite nanoparticles generally demonstrated enhanced mass activity for methanol oxidation, formic acid oxidation, and oxygen reduction compared to Pt black; however, the extent of improvement differed considerably for the various shapes. Most notably, when specific activity was compared, platinum overgrown on octahedral gold crystals showed enhanced activity per unit area for formic acid oxidation and oxygen reduction. The shape of the underlying core nanocrystals significantly affects the electrocatalytic properties of surface platinum overgrown on the gold core.

Graphical abstractElectrocatalytic properties of platinum shell overgrown on cubic, octahedral, spherical gold nanocrystals were investigated by using H adsorption/desorption, CO stripping, methanol oxidation, formic acid oxidation, oxygen reduction reaction.Figure optionsDownload full-size imageDownload high-quality image (149 K)Download as PowerPoint slideResearch highlights▶ Platinum overgrown on various shapes of gold nanocrystal (cubes, octahedra, spheres) was used as electrocatalysts. ▶ CO stripping, methanol oxidation, formic acid oxidation, and oxygen reduction reaction were performed on various Au@Pt nanoparticles and Pt black. ▶ Especially, Au(oct)@Pt nanoparticles showed enhanced specific activity for formic acid oxidation and oxygen reduction reaction.