Cyclic voltammetry (CV) of heterogeneous electrocatalysts offers a convenient means to critically assess the occurrence of “volcano plots” rendered popular by acid reduction on metal electrodes. The equations relevant to Volmer–Heyrovsky-type reactions shows that the adsorption free energy of the surface-bound intermediate is one of the rate-controlling parameters, which, plotted against the exchange current, could lead to a volcano-looking curve if other rate-controlling factors such as the rate ratio of the two successive electron transfer steps would remain constant upon changing electrocatalyst. This is not necessarily the case in practice, thus blurring the occurrence of volcano plots. Therefore, careful recording and analysis of the CV responses should be a preferred strategy, leading additionally to catalytic Tafel plots for rational electrocatalyst benchmarking. The alternative Volmer–Tafel mechanism gives remarkably rise to S-shaped current–potential responses and to a volcano upon plotting the exchange current against the adsorption standard free energy of the primary intermediate. Again, a wealth of kinetic information results from the characteristics of the current–potential responses.

中文翻译：

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表面活性位点催化电化学反应：通过循环伏安法分析火山图的发生和意义

非均相电催化剂的循环伏安法（CV）提供了一种便捷的方法，可以严格地评估由于金属电极上的酸还原而引起的“火山图”的发生。与Volmer-Heyrovsky型反应有关的方程表明，表面结合中间体的吸附自由能是速率控制参数之一，如果与其他交换速率成比例，则相对于交换电流绘制该曲线可能会形成火山似的曲线当改变电催化剂时，诸如两个连续的电子转移步骤的速率比之类的控制因素将保持恒定。实际上，情况并非一定如此，因此会模糊火山图的发生。因此，仔细记录和分析CV反应应该是一种首选策略，进一步导致了催化Tafel图的建立，以进行合理的电催化剂基准测试。通过将交换电流与主要中间体的吸附标准自由能作图，Volmer-Tafel的替代机制显着提高了S形电流势响应和火山的影响。同样，大量的动力学信息是由电流-电位响应的特征产生的。