Navigating iR Compensation: Practical Considerations for Accurate Study of Oxygen Evolution Catalytic Electrodes
Navigating iR Compensation: Practical Considerations for Accurate Study of Oxygen Evolution Catalytic Electrodes
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导航 iR 补偿：准确研究析氧催化电极的实际考虑因素
DOI：
10.1021/acsenergylett.3c01658
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发表时间：
2023
影响因子：
22
通讯作者：
Mullins, C. Buddie
中科院分区：
文献类型：
--
作者：
Son, Yoon Jun;Marquez, Raul A.;Kawashima, Kenta;Smith, Lettie A.;Chukwuneke, Chikaodili E.;Babauta, Jerome;Mullins, C. Buddie
在三电极电化学系统中，工作电极和参比电极之间的非补偿电阻（Ru）导致称为iR电位降的静电电位降，其中i是测量的电流。1，2这个iR电位降使施加的电位偏斜，这意味着电化学家设定的电位不是真正的施加电位。因此，需要进行iR补偿以精确地研究电位依赖性电化学行为。有三种常用的iR补偿方法：（1）正反馈（PF）、（2）电流中断（CI）和（3）电化学分析后的iR后补偿（Post）。3，4对于Ru测量，基于交流（AC）技术的电化学阻抗谱（EIS）分析（通过软件自动或手动）用于PF和后补偿方法。另一方面，基于直流（DC）技术的电流中断用于CI补偿方法（有关Ru测量和iR补偿方法的详细信息，请参见支持注释1）。3然而，尽管上述补偿方法很常见，但仍存在执行不准确的iR补偿的潜在风险，可能会导致误导性结果。这种风险可能是由于对这些补偿方法所涉及的基本概念以及实验和分析方法缺乏了解而产生的。已经进行了许多研究和审查，以解决与iR补偿相关的问题。这些研究集中在主题，如Ru和i的身份，5，6测量和选择Ru，2，6 Ru的最小化，2过度补偿的iR电位下降，7模糊的iR补偿的程度，8不一致的结果，从不同的iR补偿方法，4和数据处理后的iR补偿。7然而，iR补偿的实际应用，如图1所示，在精确测量和解释Ru、选择适当的iR补偿方法以及理解其对电化学分析的影响方面，仍然是一项具有挑战性的任务。这主要是由于各种电化学系统的复杂性。取决于诸如特定的电化学反应等因素（例如，水电解和CO2电解）、电极特性（例如，组成和结构）以及电化学测试的实验条件（例如，电解质、电池设计、外加电位和工作电流），Ru的物理特性及其与特定IR补偿方法的兼容性可以显著变化。电极碱性析氧反应（OER）系统具有几个独特的特征，在应用iR补偿时应考虑这些特征。首先，基于3d-过渡金属（例如Ni、Co和Fe）的碱性OER电催化剂通常在OER期间形成水合金属（氧）氢氧化物（MOxHy）。9− 12这些MOxHy相通常表现出低电导率，并且在阳极氧化还原反应（M2+/M3+）后变得更导电。2此外，由于高离子导电电解质（例如，1 M KOH）和工作电极与参比电极之间的短距离，通常代表Ru的溶液电阻保持恒定且相对较小（约2 Ω）。2因此，与具有显著溶液电阻的其他电化学系统（例如，在0.1 M KHCO 3中的CO2还原）相比，工作电极侧的电阻可以成为Ru的相对重要的组成部分。4综合考虑这些因素，碱性OER体系中的Ru可由四种主要组分组成，即：
In a three-electrode electrochemical system, uncompen-sated resistance (Ru) between the working and reference electrodes results in an electrostatic potential drop called iR potential drop, where i is a measured current. 1, 2 This iR potential drop skews the applied potential, meaning the potential set by the electrochemist is not the true applied potential. Thus, iR compensation needs to be performed to study the potential-dependent electrochemical behavior precisely. There are three commonly used methods for iR compensation:(1) positive feedback (PF),(2) current interrupt (CI), and (3) post-iR compensation after electrochemical analysis (Post). 3, 4 For the Ru measurement, alternating current (AC) technique-based electrochemical impedance spectroscopy (EIS) analysis, either automatically by software or manually, is used for PF and Post compensation methods. On the other hand, direct current (DC) techniquebased current interruption is used for the CI compensation method (see Supporting Note 1 for details about the Ru measurement and iR compensation methods). 3 However, despite the common use of the aforementioned compensation methods, there is a potential risk of performing inaccurate iR compensation that may lead to misleading results. This risk can arise from a lack of understanding of the underlying concepts and experimental and analytical methodologies involved in these compensation methods. Numerous studies and reviews have been conducted to address the concerns related to iR compensation. These studies focus on topics such as the identity of Ru and i, 5, 6 measurement and selection of Ru, 2, 6 minimization of Ru, 2 overcompensation of iR potential drop, 7 ambiguity about the degree of iR compensation, 8 inconsistent results from different iR compensation methods, 4 and data processing for post iR compensation. 7 Nevertheless, the practical application of iR compensation, in terms of accurate measurement and interpretation of Ru, selection of an appropriate iR compensation method, and understanding their effects on electrochemical analyses, as depicted in Figure 1, remains a challenging task. This is primarily due to the complexity of various electrochemical systems. Depending on factors such as the specific electrochemical reaction (eg, water electrolysis and CO2 electrolysis), electrode properties (eg, composition and structure), and experimental conditions for electrochemical testing (eg, electrolyte, cell design, applied potential, and operating current), the physical identity of Ru and its compatibility with a particular iR compensation method can vary significantly.The three-electrode alkaline oxygen evolution reaction (OER) system presents several unique characteristics that should be considered when applying iR compensation. First, alkaline OER electrocatalysts based on 3d-transition metals (eg, Ni, Co, and Fe) commonly form hydrous metal (oxy) hydroxides (MOxHy) during the OER. 9− 12 These MOxHy phases typically exhibit low electrical conductivity and become more conductive after the anodic redox reaction (M2+/M3+). 2 In addition, the solution resistance, which conventionally represents Ru, remains constant and relatively small (around 2 Ω) due to the highly ionic conductive electrolytes (eg, 1 M KOH) and the short distance between the working and reference electrodes. 2 Accordingly, the resistance on the working electrode side can become a relatively significant component of Ru compared to other electrochemical systems with significant solution resistance (eg, CO2 reduction in 0.1 M KHCO3). 4 Considering these factors, Ru in the alkaline OER system can consist of four main components, as …
电催化研究的 iR 补偿：注意事项和建议
影响因子：
22
作者：
Weiran Zheng
通讯作者：
Weiran Zheng
影响因子：
8.5
作者：
Yoon Jun Son;Kenta Kawashima;Raúl A. Márquez;Lettie A. Smith;C. Chukwuneke;C. Mullins
通讯作者：
Yoon Jun Son;Kenta Kawashima;Raúl A. Márquez;Lettie A. Smith;C. Chukwuneke;C. Mullins
影响因子：
12.9
作者：
Yoon Jun Son;Seonwoo Kim;V. Leung;Kenta Kawashima;Jungchul Noh;Kihoon Kim;Raúl A. Márquez;Omar A
通讯作者：
Yoon Jun Son;Seonwoo Kim;V. Leung;Kenta Kawashima;Jungchul Noh;Kihoon Kim;Raúl A. Márquez;Omar A