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Some aspects of the chlorine evolution reaction at ruthenium dioxide anodes

1979; Elsevier BV; Volume: 101; Issue: 3 Linguagem: Inglês

10.1016/s0022-0728(79)80045-5

2590-2954

L.D. Burke, John F. O’Neill,

Advanced battery technologies research

Cyclic voltammograms for ruthenium dioxide-coated titanium electrodes in acid solutionwere unaffected, below 1.2 V, by the addition of large quantities of chloride ions. Chlorine discharge at such surfaces was assumed to involve participation of surface oxygen species such as Oads, rather than specific adsorption of Cl− ions, at the oxide surface. In contrast to the oxygen evolution reaction, the rate of chlorine evolution was independent of both the roughness factor and the oxide loading of these anodes, the discharge apparently occurring at the external surface of these microporous electrodes. In view of the reversibility of the chlorine/chloride electrode system, especially as compared with oxygen, the main factor influencing the rate of chlorine evolution was assumed to be transfer of chlorine gas away from the electrode surface. Deviations from simple Tafel behaviour were also attributed to mass transfer of the product. Cyclic voltammograms recorded at various temperatures indicated that reduction of the oxide layer at potentials below about 0.3 V was considerably enhanced by an increase in temperature.