The effect of pH on oxygen and hydrogen peroxide reduction on polycrystalline Pt electrode
The effect of pH on oxygen and hydrogen peroxide reduction on polycrystalline Pt electrode
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DOI：
10.1016/j.electacta.2010.10.057
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发表时间：
2011
影响因子：
6.6
通讯作者：
S. Štrbac
中科院分区：
文献类型：
--
作者：
S. Štrbac
用旋转圆盘电极技术研究了多晶Pt在硫酸盐溶液中的氧还原（ORR）和过氧化氢还原（HPRR）反应。ORR和HPRR的初始电位与PtOH形成的电位区域一致，并随着溶液pH的增加而负移。对于pH值低于3.0和高于10.0的情况，ORR分别通过酸性和碱性溶液中的4e系列途径发生。对于3.0<pH<6.0，交换的电子总数取决于电势，并且对于ORR，福尔斯低于4，对于HPRR，低于2。这表明，由于在这些反应过程中局部pH值的变化，这两种反应在有限程度上发生，这导致极化曲线中的双波（如在pH 3.5和pH 4.0的ORR和pH 4.0的HPRR中观察到的）。Tafel斜率随电位的变化表明反应途径从酸性溶液中发生的变化变为碱性溶液中发生的变化。
Oxygen reduction (ORR) and hydrogen peroxide reduction (HPRR) reactions were studied on polycrystalline Pt by the rotating disc electrode technique in sulphate solutions over the entire pH range. Initial potentials for both ORR and HPRR coincide with the potential region of PtOH formation and shift negatively with the increase of the pH of the solution. For pHs lower than 3.0 and higher than 10.0, the ORR takes place through 4e-series pathways from acid and alkaline solutions, respectively. For 3.0<pH<6.0, the overall number of electrons exchanged depends on the potential and falls below 4 for ORR and below two for HPRR. This indicates that both reactions occur in a limited extent due to the changes of the local pH in the course of these reactions which gives rise to the double wave in the polarization curves (as observed for ORR for pH 3.5 and pH 4.0 and for HPRR for pH 4.0). The change of the Tafel slopes with potential indicate the change in reaction pathway from one that takes place in acid – to one that takes place in alkaline solution.