CO electrooxidation on well-characterized Pt-Ru alloys
- Univ. of California, Berkeley, CA (United States) Lawrence Berkeley Lab., CA (United States)
The electrocatalytic activity of well-characterized Pt-Ru alloy electrodes toward the electrooxidation of CO in acidic electrolyte at room temperature was measured on alloy surfaces prepared in UHV (ultrahigh vacuum). Clearly defined surface composition was determined via LEIS (low-energy ion scattering). Electrocatalytic activities were measured by CO stripping voltammetry as well as by potentiostatic oxidation of adsorbed CO. It was found that the property of Ru atoms to nucleate oxygen-containing species at low potentials produced a strong enhancement in the catalytic activity of sputter-cleaned Pt-Ru alloy electrodes compared to pure Pt, thereby supporting the concept of the bifunctional character of the oxidation process of these alloys. A further synergistic effect of the alloy with a Ru surface composition of approximately 50 atom % Ru was observed, with a catalytic shift in the CO electrooxidation current of -0.25 and -0.15 V compared to those of pure Pt and pure Ru surfaces, respectively. This synergism was attributed to a uniquely active state of OH[sub ads] on Pt-Ru pair sites. The different electrocatalytic activities of sputter-cleaned versus annealed Pt-Ru alloy electrodes with essentially identical Ru surface compositions are discussed in terms of Ru clustering during annealing. 48 refs., 8 figs., 1 tab.
- DOE Contract Number:
- AC03-76SF00098
- OSTI ID:
- 5182735
- Journal Information:
- Journal of Physical Chemistry; (United States), Vol. 98:2; ISSN 0022-3654
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
36 MATERIALS SCIENCE
CARBON MONOXIDE
ADSORPTION
OXIDATION
PLATINUM ALLOYS
ANNEALING
SPUTTERING
SURFACE PROPERTIES
RUTHENIUM ALLOYS
ACIDIZATION
ELECTROCATALYSTS
ELECTROCHEMISTRY
ELECTRODES
ELECTROLYTES
ION SCATTERING ANALYSIS
SOLID CLUSTERS
SYNERGISM
VOLTAMETRY
ALLOYS
CARBON COMPOUNDS
CARBON OXIDES
CATALYSTS
CHALCOGENIDES
CHEMICAL ANALYSIS
CHEMICAL REACTIONS
CHEMISTRY
HEAT TREATMENTS
NONDESTRUCTIVE ANALYSIS
OXIDES
OXYGEN COMPOUNDS
PLATINUM METAL ALLOYS
SORPTION
400201* - Chemical & Physicochemical Properties
400400 - Electrochemistry
360104 - Metals & Alloys- Physical Properties