Wippermann K, Giffin J, Kuhri S, Lehnert W, Korte C
Forschungszentrum Jülich GmbH, Institute of Energy and Climate Research - Fuel Cells (IEK-3), 52425 Jülich, Germany.
Phys Chem Chem Phys. 2017 Sep 20;19(36):24706-24723. doi: 10.1039/c7cp04003b.
The influence of the water content of 2-sulfoethylmethylammonium trifluoromethanesulfonate [2-Sema][TfO] on the double layer properties of the interface of platinum and the proton conducting ionic liquid (PIL) is investigated by means of impedance spectroscopy and cyclic voltammetry. By fitting the impedance spectra as complex capacitances, up to four differential double layer capacitances and corresponding time constants are obtained, depending on the potential (U = 0-1.6 V/RHE), water content (0.7-6.1 wt%) and temperature (T = 70-110 °C). Within the whole potential range investigated, a high frequency capacitance, C, and a low frequency capacitance, C, can be calculated. In the potential region of hydrogen underpotential deposition (H), C can be separated into two parts, C and C. Whereas the high frequency capacitive processes can mainly be attributed to ion transport processes in the double layer, the low frequency process is ascribed to changes in the interfacial layer, including ad-/desorption and Faradaic processes. Alternative interpretations regarding the reorientation of ions, reconstruction of the metal surface and partial electron transfer between anions and Pt are considered.
通过阻抗谱和循环伏安法研究了三氟甲磺酸2-磺基乙基甲基铵[2-Sema][TfO]的含水量对铂与质子传导离子液体（PIL）界面双层性质的影响。通过将阻抗谱拟合为复电容，根据电势（U = 0 - 1.6 V/RHE）、含水量（0.7 - 6.1 wt%）和温度（T = 70 - 110 °C），可获得多达四个微分双层电容和相应的时间常数。在所研究的整个电势范围内，可以计算出一个高频电容C和一个低频电容C。在氢欠电位沉积（H）的电势区域中，C可分为两部分，C和C。高频电容过程主要归因于双层中的离子传输过程，而低频过程则归因于界面层的变化，包括吸附/解吸和法拉第过程。还考虑了关于离子重新取向、金属表面重构以及阴离子与Pt之间部分电子转移的其他解释。
