Oxygen evolution reaction (OER) is of crucial importance to sustainable energy and environmental engineering, and layered double hydroxides (LDHs) are among the most active catalysts for OER in alkaline conditions, but the reaction mechanism for OER on LDHs remains controversial. Distinctive types of reaction mechanisms have been proposed for the O-O coupling in OER, yet they compose a coupled reaction network with competing kinetics dependent on applied potentials. Herein, we combine grand-canonical methods and micro-kinetic modeling to unravel that the nature of dominant mechanism for OER on LDHs transitions among distinctive types as a function of applied potential, and this arises from the interplay among applied potential and competing kinetics in the coupled reaction network. The theory-predicted overpotentials, Tafel slopes, and findings are in agreement with the observations of experiments including isotope labelling. Thus, we establish a computational methodology to identify and elucidate the potential-dependent mechanisms for electrochemical reactions.

析氧反应（OER）对于可持续能源和环境工程至关重要，层状双氢氧化物（LDHs）是碱性条件下最活跃的OER催化剂之一，但LDHs上OER的反应机制仍存在争议。对于 OER 中的 OO 耦合，已经提出了不同类型的反应机制，但它们组成了一个耦合反应网络，其竞争动力学取决于所施加的电位。在此，我们结合大经典方法和微观动力学模型来揭示LDHs上OER的主导机制的性质作为施加电位的函数在不同类型之间转变，而这是由于耦合反应网络中施加电位和竞争动力学之间的相互作用而产生的。理论预测的超电势、塔菲尔斜率、研究结果与包括同位素标记在内的实验观察结果一致。因此，我们建立了一种计算方法来识别和阐明电化学反应的电位依赖性机制。