Octahedral PtNi Nanoparticle Catalysts: Exceptional Oxygen Reduction Activity by Tuning the Alloy Particle Surface Composition

• Published in: Nano letters Vol. 12; no. 11; pp. 5885 - 5889
• Main Authors: Cui, Chunhua, Gan, Lin, Li, Hui-Hui, Yu, Shu-Hong, Heggen, Marc, Strasser, Peter
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 14.11.2012
• Subjects: Catalytic methods; Cross-disciplinary physics: materials science; rheology; Electrocatalysts; Exact sciences and technology; Gain; Growth from solutions; Ligands; Materials science; Methods of crystal growth; physics of crystal growth; Methods of nanofabrication; Nanocrystalline materials; Nanoparticles; Nanoscale materials and structures: fabrication and characterization; Nanostructure; Physics; Platinum; Platinum base alloys; Reduction; Surface chemistry; Tuning; PtNi octahedra; oxygen reduction reaction; ligand control; Surface composition; Catalysts; Electrocatalysts; Solvothermal synthesis; Selectivity; Surfactants; Precursor; Nanoparticles; Crystal growth from solutions; Ligands; Nickel; Surface area; Nanostructured materials
• ISSN: 1530-6984; 1530-6992
• DOI: 10.1021/nl3032795

We demonstrate how shape selectivity and optimized surface composition result in exceptional oxygen reduction activity of octahedral PtNi nanoparticles (NPs). The alloy octahedra were obtained by utilizing a facile, completely surfactant-free solvothermal synthesis. We show that the choice of precursor ligands controls the shape, while the reaction time tunes the surface Pt:Ni composition. The 9.5 nm sized PtNi octahedra reached a 10-fold surface area-specific (∼3.14 mA/cmPt 2) as well as an unprecedented 10-fold Pt mass based (∼1.45 A/mgPt) activity gain over the state-of-art Pt electrocatalyst, approaching the theoretically predicted limits.