Electrocatalysis in the anodic evolution of oxygen and chlorine

✍ Scribed by S. Trasatti

• Publisher: Elsevier Science
• Year: 1984
• Tongue: English
• Weight: 935 KB
• Volume: 29
• Category: Article
• ISSN: 0013-4686
• DOI: 10.1016/0013-4686(84)85004-5

✦ Synopsis

Requisites for electrode materials to be suitable for technological applications are outlined and discussed. Oxides with metallic or quasi-metallic conductivity meet these requirements best. Most of these electrodes are prepared by thermal procedures. It is shown that the temperature of preparation affects the catalytic activity through the surface area and the chemical composition (non-stoichiometry). The covariation of these parameters is best followed in situ by voltammetric curves and point of zero charge measurements. Examples are given for pure RuO,, IrO,. CosO, and 1rQ-t RuOz mixtures. Kinetic and mechanistic detailsare discussed for 0s evolution on RuO,,IrO, and CosOI and for Cl, evolution on RuO, and Co30,. Finally, the electrocatalytic properties of different oxides are correlated with the energy change involved in the lower * higher valency state transition. Experimental data for both O2 and Cl* evolution can thus be organized into a "volcano" curve enabling predictive interpolations to be made. M; _,