Abstract
DURING a study of electrolytic oxidation processes, the surprising observation has been made that the presence of low concentrations of certain reducing agents, which normally function as depolarizers, will bring about very substantial increases in the potential at which oxygen is evolved at a platinum anode. The effect was first noted with dilute solutions of sodium thiosulphate in phosphate buffer electrolysed at high current densities, but it has since been found to occur to varying extents with a large number of oxidizable substances containing sulphur and/or nitrogen. The phenomenon has been studied by polarizing a clean platinum wire anode in an inert electrolyte until the potential became substantially steady; a quantity of the oxidizable substance was then added and the anode potential observed over a further period of electrolysis. In general, where the added substance was active in giving the effect, an almost immediate rise of potential occurred which reached a maximum value within a few minutes. Below are shown the elevations of anode potential observed after two minutes with a variety of addition agents, each at a concentration of 0·01 M, in the electrolysis of a phosphate buffer (0·2 M, KH2PO4 + 0·2 M Na2HPO4, pH 6·8) at 20° C. with an anodic current density of 0·15 amp./sq. cm.
Similar content being viewed by others
Article PDF
References
Müller, Z. Elektrochem., 10, 776 (1904). Müller and Scheller, Z. anorg. Chem., 48, 112 (1906).
Hickling and Hill (unpublished work).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
HICKLING, A., WILSON, W. Increase of Oxygen Overpotential at a Platinum Anode by Reducing Agents. Nature 164, 673 (1949). https://doi.org/10.1038/164673a0
Issue Date:
DOI: https://doi.org/10.1038/164673a0
Comments
By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.