In-operando X-ray absorption spectroscopy of flash-combusted Pt@NiO in water-splitting conditions in alkaline media

This proposal aims to investigate the structural and electronic properties of flash-combusted Pt-infused NiO (Pt@NiO) coatings on Ni foam and carbon paper to enhance the efficiency and durability of alkaline water splitting, with a focus on the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). Conventional techniques such as Powder X-ray Diffraction (PXRD) have shown limitations in characterizing the ultrathin and low-loading Pt@NiO layers, resolving only substrate-related peaks. Similarly, High-Resolution Transmission Electron Microscopy (HR-TEM) and Raman spectroscopy, while providing insights into morphology, phase transitions, and surface characteristics, cannot capture atomic-scale oxidation state changes or transient intermediates occurring during HER and OER. To address these challenges, this study will employ operando X-ray Absorption Spectroscopy (XAS) at the Pt L3-edge and Ni K-edge, utilizing X-ray Absorption Near Edge Structure (XANES) and Extended X-ray Absorption Fine Structure (EXAFS) techniques. The high-flux X-ray source and multi-element fluorescence detector available at the ALBA BL22-CLÆSS beamline will enable real-time measurements under electrochemical conditions, revealing oxidation state dynamics, coordination environments, and electronic structure changes during water splitting. By integrating operando XAS data with complementary HR-TEM, Raman spectroscopy, and electrochemical performance results, this study will elucidate the role of Pt in modulating the catalytic behaviour of NiO, providing fundamental insights into the atomic-scale processes responsible for enhanced HER and OER activity. The outcomes of this research will contribute to the rational design of advanced catalysts with improved efficiency and long-term stability for industrial hydrogen production.

本研究提案旨在探究负载于镍泡沫与碳纸上的闪燃法制备掺铂氧化镍（Pt@NiO）涂层的结构与电子性质，以提升碱性水分解的效率与耐久性，重点关注析氢反应（HER）与析氧反应（OER）。传统表征技术如粉末X射线衍射（PXRD）在表征超薄、低负载量的Pt@NiO涂层时存在局限，仅能识别基底相关的衍射峰。同样，高分辨透射电子显微镜（HR-TEM）与拉曼光谱虽可提供形貌、相变及表面特性相关信息，但无法捕捉HER与OER过程中发生的原子级氧化态变化与瞬态中间体。为应对上述挑战，本研究将采用operando X射线吸收光谱（XAS），选取Pt L3边与Ni K边作为表征靶点，利用X射线吸收近边结构（XANES）与扩展X射线吸收精细结构（EXAFS）技术。ALBA BL22-CLÆSS光束线站配备的高通量X射线源与多元素荧光探测器，可实现在电化学条件下的实时测量，揭示水分解过程中的氧化态动态变化、配位环境与电子结构演变。通过将operando XAS数据与互补的HR-TEM、拉曼光谱及电化学性能测试结果相结合，本研究将阐明Pt在调控NiO催化行为中的作用，为理解提升HER与OER活性的原子级过程提供基础认知。本研究成果将助力合理设计具备更高效率与长期稳定性的先进催化剂，用于工业规模制氢。