Online electrochemical mass spectrometry combined with the rotating disk electrode method for direct observations of potential-dependent molecular behaviors in the electrode surface vicinity
Online electrochemical mass spectrometry combined with the rotating disk electrode method for direct observations of potential-dependent molecular behaviors in the electrode surface vicinity
复制标题
在线电化学质谱结合旋转盘电极法直接观察电极表面附近的电位依赖性分子行为
DOI：
10.1149/1945-7111/ab9960
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发表时间：
2020
影响因子：
3.9
通讯作者：
T. Wadayama
中科院分区：
文献类型：
--
作者：
N. Todoroki;H. Tsurumaki;H. Tei;T. Mochizuki;T. Wadayama
我们新开发了一种旋转盘电极在线电化学质谱仪（RDE-OLEMS），用于研究在反应分子的传质控制条件下电极表面附近的电位依赖性分子行为。通过使用四极质谱仪（Q-mass）研究电势依赖性分子行为，其中通过位于电极表面附近的气体采样尖端收集分子。对于多晶 Pt 电极上的氧还原反应 (ORR)，归因于溶解氧分子的电位依赖性 O 2 (m/z= 32) Q 质量离子信号强度随着圆盘电极旋转速率线性增加，而不受收集尖端的实质性干扰，清楚地表明 ORR 的溶解 O 2 可以通过 RDE-OLEMS 进行监测。对于多晶 Au 电极上的电化学二氧化碳还原 (ECR)，ECR 生成的 CO (m/z= 28) 的电势依赖性 Q 质量离子信号强度随着圆盘旋转速率从 0（无圆盘旋转）到 300 rpm（电位范围从− 0.4 V 到− 1.4 V 与可逆氢电极相比）的增加而增加。结果表明，RDE-OLEMS 使我们能够评估在传质控制条件下电极表面附近存在的反应物和产物分子的电势依赖性行为。
We newly developed a rotating disk electrode-online electrochemical mass spectrometry (RDE-OLEMS) to investigate potential-dependent molecular behaviors in electrode surface vicinity under mass transport-controlled conditions of reacting molecules. The potential-dependent molecular behaviors were investigated by using a quadrupole mass spectrometer (Q-mass) where the molecules are collected through a gas-sampling tip located in near the electrode surface. For the oxygen reduction reaction (ORR) on the polycrystalline Pt electrode, the potential-dependent Q-mass ion signal intensities of O 2 (m/z= 32) that are ascribable to the dissolved oxygen molecules increased linearly with the disk electrode rotation rates without substantial interference from the collection tip, clearly showing that the dissolved O 2 for ORR can be monitored by the RDE-OLEMS. For electrochemical carbon dioxide reduction (ECR) on the polycrystalline Au electrode, the potential-dependent Q-mass ion signal intensities of CO (m/z= 28) generated by the ECR increased with increasing disk rotation rates from 0 (without disk rotation) to 300 rpm in the potential region from− 0.4 to− 1.4 V vs. the reversible hydrogen electrode. The results demonstrate that the RDE-OLEMS enables us to evaluate the potential-dependent behaviors of reactant and product molecules present near the electrode surface under the mass transport-controlled condition.