Predicting macro-kinetic observables in electrocatalysis using the generalized degree of rate control
Predicting macro-kinetic observables in electrocatalysis using the generalized degree of rate control
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DOI：
10.1016/j.jcat.2021.03.014
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发表时间：
2021-04-26
影响因子：
7.3
通讯作者：
Holewinski, Adam
中科院分区：
文献类型：
--
作者：
Baz, Adam;Holewinski, Adam
动力学观测，如塔菲尔斜率，表观活化能，表观反应级数都提供了电催化过程的机械指纹。在这里，我们展示了这些量中的每一个是如何与广义速率控制度（DRC）相关的。我们发现，表观转移系数，塔菲尔斜率的倒置形式，是一个加权平均数的电子转移，以产生每个中间体或产品物种的机制，其中的权重因子是DRC。我们同样表明，表观活化能和表观反应级数（与潜在的依赖性）也可以写在简单的条款的DRC。由于DRC可以进一步与微观量，如分数覆盖的中间体，这些关系可以用来提高复杂的电催化过程的可能的操作机制的直觉。最后的讨论解决了各种非理想性，如电场效应，吸附相互作用，和近似的电化学速率常数的形式有关的可能的影响。(c)2021爱思唯尔公司All rights reserved.
Kinetic observables such as the Tafel slope, apparent activation energy, and apparent reaction orders all provide mechanistic fingerprints for electrocatalytic processes. Here, we show how each of these quantities is related to the generalized degree of rate control (DRC). We find that the apparent transfer coefficient, an inverted form of the Tafel slope, is a weighted average of the number of electrons transferred to generate each intermediate or product species in a mechanism, where the weighting factor is the DRC. We similarly show that the apparent activation energy and apparent reaction orders (with potential dependence) can also be written in simple terms of the DRC. Since DRCs can further be related with microscopic quantities such as fractional coverages of intermediates, these relations can be used to improve intuition about possible operative mechanisms of complex electrocatalytic processes. Final discussions address the possible impacts of various nonidealities such as electric field effects, adsorbate interactions, and approximations related to the form of electrochemical rate constants.(c) 2021 Elsevier Inc. All rights reserved.