van der Heijden Onno, Vos Rafaël E, Koper Marc T M
Leiden Institute of Chemistry, Leiden University, 2333 CC Leiden, The Netherlands.
ACS Energy Lett. 2025 Jun 3;10(6):3040-3049. doi: 10.1021/acsenergylett.5c01387. eCollection 2025 Jun 13.
Kinetic parameters of the oxygen evolution reaction on NiFeOOH remain elusive. Here, we studied the temperature dependence of this reaction to extract kinetic parameters, such as the temperature-dependent Tafel slopes, transfer coefficients, (standard) apparent activation energies, and pre-exponential factors. We observe a linear increase in the Tafel slope (∼30 mV/dec at room temperature) with increasing temperature when nonkinetic effects were excluded, whereas the trend reverses when significant nonkinetic effects were involved. Standard apparent activation energies of ∼75 kJ/mol were found. This has to be interpreted with regards to the mechanism containing two electrochemical presteps prior to a chemical rate-determining step (EEC or EC) and consists mostly of the free energy of the pre-equilibrium steps. The apparent activation energy at an overpotential of 0.265 V then decreased to ∼13 kJ/mol. Therefore, temperature-dependent studies can provide important mechanistic insights into electrocatalytic reactions, provided care is taken that nonkinetic effects are eliminated.
NiFeOOH上析氧反应的动力学参数仍然难以确定。在此，我们研究了该反应的温度依赖性，以提取动力学参数，如温度依赖性塔菲尔斜率、传递系数、（标准）表观活化能和指前因子。当排除非动力学效应时，我们观察到随着温度升高，塔菲尔斜率（室温下约为30 mV/dec）呈线性增加，而当涉及显著的非动力学效应时，趋势则相反。发现标准表观活化能约为75 kJ/mol。这必须根据在化学速率决定步骤（EEC或EC）之前包含两个电化学预步骤的机理来解释，并且主要由预平衡步骤的自由能组成。然后，在过电位为0.265 V时，表观活化能降至约13 kJ/mol。因此，只要注意消除非动力学效应，温度依赖性研究可以为电催化反应提供重要的机理见解。
