Understanding Cation Trends for Hydrogen Evolution on Platinum and Gold Electrodes in Alkaline Media.
Understanding Cation Trends for Hydrogen Evolution on Platinum and Gold Electrodes in Alkaline Media.
复制标题
DOI：
10.1021/acscatal.1c04268
复制
发表时间：
2021-12-03
期刊：
影响因子：
12.9
通讯作者：
Koper MTM
中科院分区：
文献类型：
--
作者：
Monteiro MCO;Goyal A;Moerland P;Koper MTM
在这项工作中，我们研究了阳离子的身份和浓度如何改变析氢反应（HER）的动力学在铂和金电极。以前的工作表明，当比较铂和金催化剂在碱性介质中的性能时，作为碱金属阳离子的函数，活性趋势相反。我们表明，弱水合阳离子（K+）有利于HER金只在低过电位（或较低的碱度），而在更碱性的pH值（或高过电位），观察到使用电解质含有强水合阳离子（Li+）的较高的活性。我们发现铂也有类似的趋势;然而，在较低的碱度和较低的阳离子浓度下，已经观察到弱水合阳离子对铂的HER抑制作用，这表明铂与金属阳离子的相互作用比金更强。我们建议，弱水合阳离子稳定的过渡态的水解离步骤更有利地由于其较高的近表面浓度相比，强水合阳离子，如Li+。然而，在高pH值和因此较高的近表面阳离子浓度，这些物种的积累在外部亥姆霍兹平面抑制HER. This是特别明显的铂，其中在速率决定步骤的变化是观察到在pH值13时，使用Li+或K+的电解质。
In this work, we study how the cation identity and concentration alter the kinetics of the hydrogen evolution reaction (HER) on platinum and gold electrodes. A previous work suggested an inverted activity trend as a function of alkali metal cation when comparing the performance of platinum and gold catalysts in alkaline media. We show that weakly hydrated cations (K+) favor HER on gold only at low overpotentials (or lower alkalinity), whereas in more alkaline pH (or high overpotentials), a higher activity is observed using electrolytes containing strongly hydrated cations (Li+). We find a similar trend for platinum; however, the inhibition of HER by weakly hydrated cations on platinum is observed already at lower alkalinity and lower cation concentrations, suggesting that platinum interacts more strongly with metal cations than gold. We propose that weakly hydrated cations stabilize the transition state of the water dissociation step more favorably due to their higher near-surface concentration in comparison to a strongly hydrated cation such as Li+. However, at high pH and consequently higher near-surface cation concentrations, the accumulation of these species at the outer Helmholtz plane inhibits HER. This is especially pronounced on platinum, where a change in the rate-determining step is observed at pH 13 when using a Li+- or K+-containing electrolyte.
登录
查看更多内容
影响因子：
--
作者：
FRUMKIN, AN
通讯作者：
FRUMKIN, AN
影响因子：
15
作者：
Goyal, Akansha;Marcandalli, Giulia;Koper, Marc T. M.
通讯作者：
Koper, Marc T. M.
影响因子：
3.9
作者：
Li, Xiang;Gunathunge, Charuni M.;Waegele, Matthias M.
通讯作者：
Waegele, Matthias M.
影响因子：
9.5
作者：
Hersbach, Thomas J. P.;McCrum, Ian T.;Koper, Marc T. M.
通讯作者：
Koper, Marc T. M.
影响因子：
4.4
作者：
Goyal, Akansha;Koper, Marc T. M.
通讯作者：
Koper, Marc T. M.