Browne Michelle P, Domínguez Carlota, Kaplan Can, Lyons Michael E G, Fonda Emiliano, Colavita Paula E
School of Chemistry, CRANN and AMBER Research Centres, Trinity College Dublin, College Green, Dublin D02 PN40, Ireland.
Helmholtz Young Investigator Group Electrocatalysis: Synthesis to Devices, Helmholtz-Zentrum Berlin für Materialien und Energie, 14109 Berlin, Germany.
ACS Appl Energy Mater. 2023 Aug 16;6(16):8607-8615. doi: 10.1021/acsaem.3c01585. eCollection 2023 Aug 28.
Identifying the active site of catalysts for the oxygen evolution reaction (OER) is critical for the design of electrode materials that will outperform the current, expensive state-of-the-art catalyst, RuO. Previous work shows that mixed Mn/Ru oxides show comparable performances in the OER, while reducing reliance on this expensive and scarce Pt-group metal. Herein, X-ray photoelectron spectroscopy and X-ray absorption spectroscopy (XAS) are performed on mixed Mn/Ru oxide materials for the OER to understand structural and chemical changes at both metal sites during oxygen evolution. The results show that the Mn-content affects both the oxidation state and local coordination environment of Ru sites. Operando XAS experiments suggest that the presence of MnO might be essential to achieve high activity likely by facilitating changes in the O-coordination sphere of Ru centers.
确定用于析氧反应（OER）的催化剂的活性位点对于设计性能优于当前昂贵的先进催化剂RuO₂的电极材料至关重要。先前的工作表明，混合的Mn/Ru氧化物在OER中表现出可比的性能，同时减少了对这种昂贵且稀缺的铂族金属的依赖。在此，对用于OER的混合Mn/Ru氧化物材料进行了X射线光电子能谱和X射线吸收光谱（XAS）分析，以了解析氧过程中两个金属位点的结构和化学变化。结果表明，Mn含量会影响Ru位点的氧化态和局部配位环境。原位XAS实验表明，MnO的存在可能通过促进Ru中心的O配位球的变化对实现高活性至关重要。
