Size Influence on the Oxygen Reduction Reaction Activity and Instability of Supported Pt Nanoparticles

Journal Article · Thu Dec 15 04:00:00 EST 2011 · Journal of the Electrochemical Society

OSTI ID:1043992

Sheng, W; Vescovo, E

Size-dependent oxygen reduction reaction activity (ORR) and instability of Pt nanoparticles is of great importance in proton exchange membrane fuel cell applications. In this study, the size-dependence of ORR activity on Pt nanoparticles (NPs) was investigated on high-surface-area carbon supported Pt NPs below 5 nm in acidic electrolytes using rotating disk electrode method. The ORR activity was correlated to the estimated surface coverage by OH anion from cyclic voltammogram measurements and the surface composition and electronic structure of Pt NPs, which was studied using X-ray photoemission spectroscopy, and ultraviolet photoemission spectroscopy. The results revealed a size-independent ORR activity on Pt NPs below 5 nm, which was attributed to similar surface compositions and surface electronic structures of Pt NPs below 5 nm as well as comparable OH anion coverage at the potential where ORR was evaluated. In contrast, the instability of Pt NPs under accelerated potential cycling was found to be strongly dependent on the particle size.

• Research Organization: BROOKHAVEN NATIONAL LABORATORY (BNL)
• Sponsoring Organization: USDOE SC OFFICE OF SCIENCE (SC)
• DOE Contract Number: AC02-98CH10886
• OSTI ID: 1043992
• Report Number(s): BNL--97081-2012-JA
• Journal Information: Journal of the Electrochemical Society, Journal Name: Journal of the Electrochemical Society Journal Issue: 2 Vol. 159; ISSN JESOAN; ISSN 0013-4651
• Country of Publication: United States
• Language: English

Related Subjects

30 DIRECT ENERGY CONVERSION
36 MATERIALS SCIENCE
ANIONS
CARBON
ELECTRODES
ELECTROLYTES
ELECTRONIC STRUCTURE
INSTABILITY
OXYGEN
PARTICLE SIZE
PHOTOEMISSION
PROTON EXCHANGE MEMBRANE FUEL CELLS
SPECTROSCOPY
catalysis
nanoparticles