Diethylmethylammonium trifluoromethanesulfonate protic ionic liquid electrolytes for water electrolysis
Diethylmethylammonium trifluoromethanesulfonate protic ionic liquid electrolytes for water electrolysis
复制标题
DOI：
10.1016/j.jpowsour.2019.227602
复制
发表时间：
2020-02-15
影响因子：
9.2
通讯作者：
Mamlouk, Mohamed
中科院分区：
文献类型：
--
作者：
Thimmappa, Ravikumar;Walsh, Darren;Mamlouk, Mohamed
质子离子液体（PIL）具有宽的电化学稳定性、良好的离子电导率、低的蒸气压和良好的热稳定性，是一种很有前途的电化学电解质。在这项研究中，我们证明了[Dema-H]（+）[TfO]（-）可以用作中温水电解的电解质。[Dema-H]（+）[TfO]（-）在Pt电极上的循环伏安图显示出2.5V的电位窗口，超过了水分解电位1.23V。在“制备的”[Dema-H]（+）[TfO]（-）和10% [Dema-H]（+）[TfO]（-）水溶液中，在Pt电极上观察到两个析氢反应。涉及H3 O+的第一次HER在-0.255 V处具有峰电位（相对于具有0.016 mA/cm（2）的极限电流密度的SHE，归因于Pt低表面覆盖/H+/H3 O+吸附。涉及[Dema-H] +的第二个HER在-0.475 V（相对于SHE）时开始，并且在高达0.1 mA cm（-2）（-0.8 V（相对于SHE））时未显示极限电流。第二个观察到的HER被认为是由于两个[Dema-H] +还原产生H-2和二乙基甲胺[Dema]。后者在阳极被再氧化以再生成[Dema-H]（+）。原位质谱分析证实了H-2/O-2演变在这两个电位。IrO_2在10% [Dema-H]（+）[TfO]（-）溶液中的析氧反应（OER）也有两个起始电位。
Protic ionic liquids (PILs) are promising electrolytes for electrochemical devices, owing to their wide electrochemical stability, good ionic conductivity, low vapour pressure and good thermal stability. In this study, we demonstrate that [Dema-H](+) [TfO](-) can be used as an electrolyte for intermediate temperature water electrolysis. The cyclic voltammograms of [Dema-H](+) [TfO](- )on Pt show a potential window of 2.5 V which is beyond water decomposition potential of 1.23 V. Two hydrogen evolution reactions are observed on Pt electrode in both "as prepared" [Dema-H](+) [TfO](-) and 10% [Dema-H](+) [TfO](-) in water. The first HER involving H3O+ had a peak potential at -0.255 V (vs SHE with limiting current density of 0.016 mA/cm(2) assigned to Pt low surface coverage/adsorption of H+/H3O+. The second HER involving [Dema-H] + had an on-set at -0.475 V vs SHE and did not show limiting current up to 0.1 mA cm(-2) (-0.8 V vs. SHE). Second observed HER is believed to be due to reduction of two [Dema-H] + to produce H-2 and diethyl methyl amine [Dema]. The latter is reoxidised at anode to reproduce [Dema-H](+). In-situ mass spectrometric analysis confirmed H-2/O-2 evolution at both potentials. The oxygen evolution reaction (OER) on IrO2 in 10% [Dema-H](+) [TfO](-) also shows two onset potentials.