ISSN:
1572-8838
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
,
Electrical Engineering, Measurement and Control Technology
Notes:
Abstract Ruthenium electrodes subjected to an anodic/cathodic potential cycling regime from 0.06 to 1.4E H develop a changed state of surface oxidation in comparison with that observed in the initial sequence of potentiodynamic sweeps. The cycling effect is analogous to that known at iridium electrodes but here refers to monolayers. The kinetics of Cl2 and O2 evolution of these two types of oxidized surfaces were studied by steady-state polarization experiments. Current densities for Cl2 evolution at the cycled Ru surface oxide areca 30 times greater than those at the original oxidized Ru surface. Oxygen evolution current densities are increased byca 8 times. The effect is a true electrocatalytic one since the real area of the Ru surfaces remains constant withinca 5%. The mechanisms of Cl2 or O2 evolution appear to remain unchanged, so the electrocatalytic effects observed are tentatively attributed to a change of potential range over which Ru(III) and Ru(IV) oxidation states arise in the oxide film causing modification of electron transfer rates or adsorption of ions and intermediates.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00616901
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