Design criteria for the competing chlorine and oxygen evolution reactions: avoid the OCl adsorbate to enhance chlorine selectivity.

摘要: The formation of gaseous chlorine within chlor-alkali electrolysis is accompanied by a selectivity problem, as the evolution oxygen constitutes detrimental side reaction in same potential range. As such, development electrode materials with high toward particular importance to chemical industry. Insight into elementary steps ultimately required comprehend on molecular level. Commonly, linear scaling relationships are analyzed construction volcano plot, using binding energy oxygen, ΔEO, descriptor analysis. present article reinvestigates problem competing and reactions applying different strategy compared previous literature studies. On one hand, unifying material-screening framework that, besides energies, also includes applied overpotential, kinetics, electrochemical-step symmetry index used trends this issue for transition-metal oxide-based electrodes. other free-energy difference between adsorbed hydroxide, ΔG2, rather than ΔEO It demonstrated that OCl adsorbate inherently limits selectivity, whereas, optimum case, Cl intermediate can result significantly higher selectivity. This finding derive design criteria highly selective electrocatalysts, which be future search compositions techniques.