Stabilization of Platinum Oxygen-Reduction Electrocatalysts Using Gold Clusters

• Published in: Science (American Association for the Advancement of Science) Vol. 315; no. 5809; pp. 220 - 222
• Main Authors: Zhang, J, Sasaki, K, Sutter, E, Adzic, R.R
• Format: Journal Article
• Language: English
• Published: Washington, DC American Association for the Advancement of Science 12-01-2007; The American Association for the Advancement of Science
• Subjects: Absorption spectra; Applied sciences; Atoms; Catalysis; Catalysts; Chemistry; Clusters; Colloidal state and disperse state; Cycles; Dissolution; Electrocatalysts; Electrochemistry; Electrodes; Energy; Energy. Thermal use of fuels; Equipments for energy generation and conversion: thermal, electrical, mechanical energy, etc; Exact sciences and technology; Fuel cells; General and physical chemistry; Gold; Gold alloys; In vehicle; Kinetics and mechanism of reactions; Nanoparticles; Oxidation; Oxides; Physical and chemical studies. Granulometry. Electrokinetic phenomena; Platinum; Reduction; Room temperature; Surface areas; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; Gold; Oxygen; Nanoparticle; Stabilization; Transition metal; Carbon; Supported catalyst; Chemical reduction; Heterogeneous catalysis; Electrocatalysis; Platinum; Oxidation potential; Fuel cell
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.1134569

We demonstrated that platinum (Pt) oxygen-reduction fuel-cell electrocatalysts can be stabilized against dissolution under potential cycling regimes (a continuing problem in vehicle applications) by modifying Pt nanoparticles with gold (Au) clusters. This behavior was observed under the oxidizing conditions of the O₂ reduction reaction and potential cycling between 0.6 and 1.1 volts in over 30,000 cycles. There were insignificant changes in the activity and surface area of Au-modified Pt over the course of cycling, in contrast to sizable losses observed with the pure Pt catalyst under the same conditions. In situ x-ray absorption near-edge spectroscopy and voltammetry data suggest that the Au clusters confer stability by raising the Pt oxidation potential.