Department of Materials Science and Engineering, Cornell University, Ithaca, New York 14853, USA.
Laboratory of Atomic and Solid State Physics, Cornell University, Ithaca, New York 14853, USA.
J Chem Phys. 2019 Jan 28;150(4):041726. doi: 10.1063/1.5051429.
We report the electrocatalysis of the chlorine evolution reaction (CER) on well-defined RuO(110) and IrO(110) surfaces. RuO and IrO are known for their capabilities to catalyze the CER. Until now, the CER measurements have only been reported on well-defined RuO surfaces and only at high Cl concentrations. We present the CER measurement and the role of Cl at lower concentration on single-orientation RuO(110) and IrO(110) films. We find that RuO(110) is two orders of magnitude more active than IrO(110). Moreover, we observe the correlation between the CER activity and the O formation potential on RuO and IrO, supporting the prior suggestion that the O is the active site for the CER. We further use the reaction order analysis to support the Volmer-Heyrovsky mechanism of the CER, which was previously suggested from the Tafel slope analysis. Our finding highlights the importance of the surface O species on oxides for the CER electrocatalysis and suggests the electrochemical formation of Cl on O (for example, Cl + O ↔ OCl + e) as the crucial step in the CER electrocatalysis.
我们报告了在明确的 RuO(110) 和 IrO(110) 表面上的氯进化反应 (CER) 的电催化作用。RuO 和 IrO 以其催化 CER 的能力而闻名。到目前为止，仅在明确的 RuO 表面上并在高 Cl 浓度下才报告了 CER 测量。我们在单取向 RuO(110) 和 IrO(110) 薄膜上报告了 CER 测量以及在低浓度下 Cl 的作用。我们发现 RuO(110) 的活性比 IrO(110) 高两个数量级。此外，我们观察到 CER 活性与 RuO 和 IrO 上的 O 形成势之间的相关性，这支持了 O 是 CER 活性位点的先前建议。我们进一步使用反应级数分析来支持 CER 的 Volmer-Heyrovsky 机制，该机制先前是从 Tafel 斜率分析中提出的。我们的发现强调了氧化物表面 O 物种对 CER 电催化的重要性，并表明 Cl 在 O 上的电化学形成（例如，Cl + O ↔ OCl + e）是 CER 电催化的关键步骤。
