Methanol electro-oxidation on unsupported Pt-Ru alloys at different temperatures
- Army Research Lab., Fort Monmouth, NJ (United States). Physical Sciences Directorate
A wide compositional range of unsupported platinum-ruthenium alloy catalysts were prepared by thermal decomposition of the chlorides and chloroacids. The electrocatalysts were characterized by cyclic voltammetry, X-ray diffraction, and energy-dispersive X-ray spectroscopy. The BET surface area of the electrocatalysts increases with increasing Ru content up to {approximately}70 atomic percent (a/o) and then reaches a plateau value. Electrodes fabricated from the electrocatalysts were also evaluated as anodes for methanol electro-oxidation in sulfuric acid over a range of temperatures. Unlike the situation for pure Pt, Ru is inactive for methanol electro-oxidation at 25 C but becomes active at higher temperatures. The peak current observed during an anodic potential scan gradually shifts to more cathodic potentials with increasing temperature. When a comparison is made on the basis of electrode geometric surface area, a {approximately}50 a/o ruthenium electrocatalyst provides the highest activity for methanol electro-oxidation at both 25 and 60C. The methanol electro-oxidation rate is 0.5 orders with respect to methanol concentration (between 0.1 and 2 M) for the Pt-Ru ({approximately}50:50) electrode.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 256825
- Journal Information:
- Journal of the Electrochemical Society, Journal Name: Journal of the Electrochemical Society Journal Issue: 5 Vol. 143; ISSN JESOAN; ISSN 0013-4651
- Country of Publication:
- United States
- Language:
- English
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