Revealing Elusive Intermediates of Platinum Cathodic Corrosion through DFT Simulations
Revealing Elusive Intermediates of Platinum Cathodic Corrosion through DFT Simulations
复制标题
DOI：
10.1021/acs.jpclett.1c04187
复制
发表时间：
2022-04-07
影响因子：
5.7
通讯作者：
Alexandrov, Vitaly
中科院分区：
文献类型：
--
作者：
Evazzade, Iman;Zagalskaya, Alexandra;Alexandrov, Vitaly
120多年前发现的金属阴极腐蚀仍然是一个知之甚少的电化学过程。阴极极化过程中形成的腐蚀中间体具有较高的反应活性，是寿命极短的产物。再加上同时发生的剧烈的析氢，使得研究反应机理和实验检测中间体具有挑战性。从计算的角度来看，该过程也提出了严峻的挑战，因为它发生在相当低的负电位的浓碱性溶液中。在这里，我们使用密度泛函理论计算来阐明反应中间体的身份及其在Pt(111)/电解质界面上的反应性。通过恒定的费米能级分子动力学控制实验相关区域的电位，我们揭示了碱化稳定的Pt氢化物作为阴极腐蚀的中间产物的形成。结果还表明，所发现的Pt阴离子可以通过与表面结合的氢或溶液中的水分子反应而使界面放电产生h22
Cathodic corrosion of metals discovered more than 120 yearsago remains a poorly understood electrochemical process. It is believed thatthe corrosion intermediates formed during cathodic polarization areextremely short-lived species because of their high reactivity. Togetherwith the concurrent vigorous hydrogen evolution, this makes it challengingto investigate the reaction mechanism and detect the intermediatesexperimentally. From a computational standpoint, the process also presentsa serious challenge as it occurs at rather low negative potentials inconcentrated alkaline solutions. Here, we use density-functional-theorycalculations to elucidate the identity of reaction intermediates and theirreactivity at the Pt(111)/electrolyte interface. By controlling the electrodepotential in an experimentally relevant region through constant Fermi-level molecular dynamics, we reveal the formation of alkalication-stabilized Pt hydrides as intermediates of cathodic corrosion. The results also suggest that the found Pt anions could dischargeat the interface to produce H2by reacting with either surface-bound hydrogen species or solution water molecules