Instituto de Electroquímica, Universidad de Alicante, Apartado 99, E-03080 Alicante, Spain.
Phys Chem Chem Phys. 2013 Oct 7;15(37):15416-25. doi: 10.1039/c3cp51642c.
The oxygen reduction reaction (ORR) in 0.1 M NaOH on platinum single crystal electrodes has been studied using hanging meniscus rotating disk electrode configuration. Basal planes and stepped surfaces with (111) and (100) terraces have been employed. The results indicate that the Pt(111) electrode has the highest electrocatalytic activity among all the studied surfaces. The addition of steps on this electrode surface significantly diminishes the reactivity of the surface towards the ORR. In fact, the reactivity of the steps on the surfaces with wide terraces can be considered negligible with respect to that measured for the terrace. On the other hand, Pt(100) and Pt(110) electrodes have much lower activity than the Pt(111) electrode. These results have been compared with those obtained in acid media to understand the effect of the pH and the adsorbed OH on the mechanism. It is proposed that the surface covered by adsorbed OH is active for the reduction of the oxygen molecules.
在 0.1 M NaOH 中，使用悬滴旋转圆盘电极配置研究了铂单晶电极上的氧还原反应（ORR）。采用了基面和具有（111）和（100）平台的阶梯面。结果表明，在所有研究的表面中，Pt(111)电极具有最高的电催化活性。在该电极表面上添加台阶显著降低了表面对 ORR 的反应性。实际上，对于具有宽平台的表面上的台阶的反应性，可以认为相对于平台上测量的反应性可以忽略不计。另一方面，Pt(100)和 Pt(110)电极的活性比 Pt(111)电极低得多。将这些结果与在酸性介质中获得的结果进行了比较，以了解 pH 和吸附的 OH 对机理的影响。提出吸附的 OH 覆盖的表面对于氧分子的还原是活性的。
