Gold dissolution: towards understanding of noble metal corrosion
Gold dissolution: towards understanding of noble metal corrosion
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DOI：
10.1039/c3ra42684j
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发表时间：
2013-01-01
期刊：
影响因子：
3.9
通讯作者：
Mayrhofer, Karl J. J.
中科院分区：
文献类型：
--
作者：
Cherevko, Serhiy;Topalov, Angel A.;Mayrhofer, Karl J. J.
金的电化学溶解是一个复杂的课题，尽管已经研究了50多年，但对其理解仍然相当有限。在目前的工作中，我们通过使用由微电化学扫描流动池（SFC）和电感耦合等离子体质谱（ICP-MS）组成的装置获得关于金溶解的独特信息。因此，全面的在线金溶解曲线在氧化的初始阶段作为电位，时间和pH值的函数。一个微观模型解释的实验结果提出。根据该模型，两种溶解机制发生在两个不同的电位区域：在低阳极电位下，溶解是由金属和吸附的羟基/氧离子之间的位置交换驱动的，而在较高的电位下，氧化金表面上发生的析氧反应引发伴随的金损失。
The electrochemical dissolution of gold is an intricate topic and even though it has been studied for more than 50 years, its understanding remains rather limited. In the current work, we obtain unique information on gold dissolution by using a setup composed of a micro-electrochemical scanning flow cell (SFC) and inductively coupled plasma mass spectrometry (ICP-MS). Thus, comprehensive online gold dissolution profiles during the initial stage of oxidation as a function of the potential, time and pH are presented. A microscopic model explaining the experimental findings is proposed. According to this model, two dissolution mechanisms take place in two different potential regions: at low anodic potentials the dissolution is driven by the place-exchange between metal and adsorbed hydroxyl/oxygen ions, while at higher potentials the oxygen evolution reaction taking place on the surface of gold oxide initiates concomitant gold loss.