Probing Active Sites and Reaction Intermediates of Electrocatalysis Through Confocal Near-Infrared Photoluminescence Spectroscopy: A Perspective
Probing Active Sites and Reaction Intermediates of Electrocatalysis Through Confocal Near-Infrared Photoluminescence Spectroscopy: A Perspective
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DOI：
10.3389/fchem.2020.00327
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发表时间：
2020-04-28
影响因子：
5.5
通讯作者：
Chakrapani, Vidhya
中科院分区：
文献类型：
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作者：
Chakrapani, Vidhya
诸如析氧(OER)和氧还原反应(ORR)等电催化反应是最复杂的非均相电荷转移过程之一，因为它涉及窄电势范围内的多个质子耦合电子转移步骤和氧-氧键的形成/断裂。由于用于探测活性中间体和活性中心的常用光谱工具的固有局限性，在一些高活性、强关联的氧化物上，如MnOx、Niox和IrO(X)上获得这些反应的清晰机理图一直是具有挑战性的。本文简要总结了这类探头面临的一些关键挑战，并描述了共聚焦近红外光致发光(NIR-PL)技术在现场电化学极化研究中探测表面和体金属阳离子状态的一些独特优势。这项技术的使用为研究金属氧化物的电子结构由于缺陷平衡的扰动而发生的变化开辟了新的途径，这在催化、光催化、矿物氧化还原化学和电池等广泛的多相体系中是至关重要的。
Electrocatalytic reactions such as oxygen evolution (OER) and oxygen reduction reactions (ORR) are one of the most complex heterogeneous charge transfer processes because of the involvement of multiple proton-coupled-electron transfer steps over a narrow potential range and the formation/breaking of oxygen-oxygen bonds. Obtaining a clear mechanistic picture of these reactions on some highly active strongly-correlated oxides such as MnOx, NiOx, and IrO(x)has been challenging due to the inherent limitations of the common spectroscopic tools used for probing the reactive intermediates and active sites. This perspective article briefly summarizes some of the key challenges encountered in such probes and describes some of unique advantages of confocal near-infrared photoluminescence (NIR-PL) technique for probing surface and bulk metal cation states underin-situandex-situelectrochemical polarization studies. Use of this technique opens up a new avenue for studying changes in the electronic structure of metal oxides occurring as a result of perturbation of defect equilibria, which is crucial in a broad range of heterogeneous systems such as catalysis, photocatalysis, mineral redox chemistry, and batteries.