The influence of the extent of oxidation of Ni electrodes on the kinetics of the hydrogen oxidation (HOR) and evolution (HER) reactions has been explored by combining an experimental cyclic voltammetry and chronoamperometry study with microkinetic modeling. The HOR/HER specific activity of the Ni/NiO_x electrodes follows a volcano-type dependence with a maximum at 30% NiO_x coverage corresponding to a 14-fold increase (nominally from 2.2 to 32.8 μA cm⁻²_Ni) of the specific activity calculated as the exchange current density normalized by the electrochemical surface area of Ni active sites. The kinetic model suggests that the experimentally observed changes in the shape of current-potential curves as well as the HOR/HER specific activities are mostly due to the NiO_x coverage–dependent strength of adsorption of hydrogen atoms. The latter is accompanied by an increase of the rate of the Volmer step and a decrease of the potential of OH_ad adsorption on Ni centers in the vicinity of surface Ni oxides.

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通过将循环伏安法和计时安培法研究与微动力学模型相结合，探索了镍电极氧化程度对氢氧化（HOR）和析出（HER）反应动力学的影响。Ni / NiO _x电极的HOR / HER比活度遵循火山类型的依赖性，NiO _x覆盖率最高时达到30％，对应于14倍的增加（名义上从2.2到32.8μAcm ^-2 _Ni）的比活度计算为通过Ni活性位点的电化学表面积归一化的交换电流密度。动力学模型表明，实验观察到的电流势曲线形状以及HOR / HER比活的变化主要归因于NiO _x覆盖率依赖于氢原子的吸附强度。后者伴随着沃尔默步骤的速率增加和在表面Ni氧化物附近的Ni中心上的OH _ad吸附潜力的降低。

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