材料科学
二茂铁
电化学
X射线吸收光谱法
析氧
吸收(声学)
金属
X射线
金属有机骨架
吸收光谱法
配体(生物化学)
氧气
光谱学
X射线光谱学
光化学
分析化学(期刊)
纳米技术
物理化学
电极
光学
环境化学
冶金
吸附
有机化学
化学
生物化学
物理
受体
复合材料
量子力学
作者
Fengzhan Sun,Zhao Li,Hao Xu,Yang Fu,Hui Li,Yingying Yao,Li Ren,Xiaoqian He,Yinghui Li,Rui Yang,Nian Zhang,Zhigang Hu,Tianyi Ma,Jianxin Zou
标识
DOI:10.1002/aenm.202400875
摘要
Abstract Metal‐organic frameworks (MOFs) have exhibited encouraging catalytic activity for the oxygen evolution reaction (OER), a crucial process for water electrolysis to produce green hydrogen. Nonetheless, distinguishing the source of catalytic activity and establishing the structure‐composition‐property relationships of MOFs during OER processes remain challenging. Here, for the first time, operando X‐ray absorption spectroscopy (XAS) is utilized to monitor the structural evolution and identify the active components of ferrocene‐based MOFs (Ni‐Fc) for OER. Ligand‐defect‐rich Ni‐Fc is synthesized via the co‐deposition method. After electrochemical activation, Ni‐Fc exhibits superior electrocatalytic activity (228 mV at 10 mA cm −2 in 0.1 m KOH), which is highly competitive compared with state‐of‐the‐art electrocatalysts. Operando XAS analysis and ex‐situ characterizations reveal the structural reconstruction of Ni‐Fc into amorphous NiFe‐catalysts (a‐NiFe) during the activation process, and further into real catalytic phases (a‐NiFe‐C) under catalytic potential greater than 1.45 V (vs RHE). In catalytic phases, in‐situ formed deprotonated and oxygen‐defected Ni oxyhydroxide analogues act as catalytic sites, while Fe hydroxide analogues derived from ligands optimize the electronic structure of Ni sites for improving OER activity. Density functional theory (DFT) analysis indicates a reduced energy barrier in a‐NiFe‐C compared to pristine MOFs, supporting the improved catalytic activity of the latter.
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