【摘要】 析氧反应（OER）作为能源转化、贮存的重要过程已被广泛研究,有意思的是其阴离子因为种种原因（惰性位点,易溶解,氧化等）长久以来一直被忽视.本文制备了模型催化剂s-Ni（OH）₂来捕获催化剂中的阴离子在电化学过程中的行为以填补相关研究空白.尖端的原位同步辐射傅立叶变换红外光谱（SR-FTIR）、同步辐射光电子能谱（SRPES）深度探测和X射线吸收精细结构（Δ-XAFS）差分谱共同指出催化剂中的部分阴离子(SO₄^2-)将在OER过程中发生自优化过程形成新的Ni-S键.像这种奇异的阴离子自优化行为之前从未被观察到.随后的电化学测试表明,自优化之后衍生的真正催化剂相比于参比催化剂Ni（OH）₂表现出显著提高的电化学性能（催化活性、稳定性等）.理论计算进一步表明,阴离子自优化过程确实会衍生一个热力学稳定的结构相作为真正的催化剂,该催化剂通过优化OER的热力学和动力学过程赋予其优异的催化性能.本工作直观证明了阴离子在电化学过程中的重要作用,将为理解OER开辟新的视角,并对相关领域,尤其是催化和化学领域产生一些启发.更多还原

【Abstract】 Broadly, the oxygen evolution reaction（OER） has been deeply understood as a significant part of energy conversion and storage. Nevertheless, the anions in the OER catalysts have been neglected for various reasons such as inactive sites, dissolution, and oxidation, amongst others. Herein, we applied a model catalyst s-Ni（OH）₂ to track the anionic behavior in the catalyst during the electrochemical process to fill this gap. The advanced operando synchrotron radiation Fourier transform infrared（SR-FTIR） spectroscopy,synchrotron radiation photoelectron spectroscopy（SRPES） depth detection and differential X-ray absorption fine structure（D-XAFS） spectrum jointly point out that some oxidized sulfur species(SO₄^2-) will selfoptimize new Ni–S bonds during OER process. Such amazing anionic self-optimization（ASO） behavior has never been observed in the OER process. Subsequently, the optimization-derived component shows a significantly improved electrocatalytic performance（activity, stability, etc.） compared to reference catalyst Ni（OH）₂. Theoretical calculation further suggests that the ASO process indeed derives a thermodynamically stable structure of the OER catalyst, and then gives its superb catalytic performance by optimizing the thermodynamic and kinetic processes in the OER, respectively. This work demonstrates the vital role of anions in the electrochemical process, which will open up new perspectives for understanding OER and provide some new ideas in related fields（especially catalysis and chemistry）.更多还原