Leiden Institute of Chemistry, Leiden University, PO Box 9502, 2300 RA, Leiden, The Netherlands.
Department of Chemical Engineering, The Pennsylvania State University, 51 Greenberg Complex, University Park, PA, 16802, USA.
Angew Chem Int Ed Engl. 2017 Nov 20;56(47):15025-15029. doi: 10.1002/anie.201709455. Epub 2017 Oct 23.
The successful deployment of advanced energy-conversion systems depends critically on our understanding of the fundamental interactions of the key adsorbed intermediates (hydrogen *H and hydroxyl *OH) at electrified metal-aqueous electrolyte interfaces. The effect of alkali metal cations (Li , Na , K , Cs ) on the non-Nernstian pH shift of the step-related voltammetric peak of the Pt(553) electrode is investigated over a wide pH window (1 to 13) by means of experimental and computational methods. The co-adsorbed alkali cations along the step weaken the OH adsorption at the step sites, causing a positive shift of the potential of the step-related peak on Pt(553). Density functional calculations explain the observations on the identity and concentration of alkali cations on the non-Nernstian pH shift, and demonstrate that cation-hydroxyl co-adsorption causes the apparent pH dependence of "hydrogen" adsorption in the step sites of platinum electrodes.
先进能量转换系统的成功部署关键取决于我们对带电金属-水基电解质界面上关键吸附中间体（氢H 和羟基OH）基本相互作用的理解。通过实验和计算方法研究了碱金属阳离子（Li、Na、K、Cs）在很宽的 pH 窗口（1 至 13）内对 Pt(553)电极与台阶相关的伏安峰的非-Nernstian pH 偏移的影响。沿台阶共吸附的碱阳离子削弱了台阶处的 OH 吸附，导致 Pt(553)上与台阶相关的峰的电位发生正移。密度泛函计算解释了观察到的非-Nernstian pH 偏移中碱阳离子的种类和浓度，并表明阳离子-羟基共吸附导致了铂电极台阶处“氢”吸附的表观 pH 依赖性。
