Effect of anions and pH on the ethanol electro-oxidation at a platinum electrode

• Published in: Electrochimica acta 1982-12, Vol.27 (12), p.1683-1696
• Main Authors: Snell, K.D., Keenan, A.G.
• Format: Article
• Language: English
• ISSN: 0013-4686; 1873-3859
• DOI: 10.1016/0013-4686(82)80164-3

The electro-oxidation of ethanol and its inhibition by adsorbed chloride ions have been studied by cyclic voltammetry in 0.64 M HNO 3, 0.64 M HClO 4, 0.64 M NaNO 3, 0.64 M NaClO 4, 0.43 M NaNO 3/0.072 M Na 2SO 4 and 0.43 M NaClO 4/0.072 M Na 2SO 4 solutions at 25°C. The results show that these anions and the pH influence the peak current and potential for all three anodic waves. The anion effect is more pronounced in acidic solutions than in neutral solutions. The magnitude of the effect in the absence of chloride indicates that the surface coverage of these anions increases in the order perchlorate, sulfate, nitrate. The chloride inhibition is dependent on the anions and is smallest in sulfate solutions. Mechanisms proposed in an earlier study are found to be consistent with these results. It is also suggested that the ethanol system may be useful as a probe in studies of anion adsorption properties and platinum surface states.