通过价层到芯层X射线发射光谱研究铂镍合金中的应变和配体效应。
Strain and ligand effects in Pt-Ni alloys studied by valence-to-core X-ray emission spectroscopy.
作者信息
Chen Jiatang, Finfrock Y Zou, Wang Zhiqiang, Sham Tsun-Kong
机构信息
Department of Chemistry, University of Western Ontario, London, ON, N6A 5B7, Canada.
CLS@APS Sector 20, Advanced Photon Source, Argonne National Laboratory, Lemont, IL, 60439, USA.
出版信息
Sci Rep. 2021 Jul 1;11(1):13698. doi: 10.1038/s41598-021-93068-0.
Experimental detection of the Pt 5d densities of states in the valence band is conducted on a series of Pt-Ni alloys by high energy resolution valence-to-core X-ray emission spectroscopy (VTC-XES) at the Pt L-edge. VTC-XES measurements reveal that the Pt d-band centroid shifts away from the Fermi level upon dilution, accompanied by concentration-dependent Pt d-band width. The competition between the strain effect and ligand effect is observed experimentally for the first time. It is found that the d-band widths in PtNi and PtNi are broader than that of Pt metal due to compressive strain which overcompensates the effect of dilution, while it is narrower in PtNi where the ligand effect dominates. VTC-XES is demonstrated to be a powerful tool to study the Pt d-band contribution to the valence band of Pt-based bimetallic. The implication for the enhanced activity of Pt-Ni catalysts in oxygen reduction reaction is discussed.
通过在铂L边进行的高能分辨价带至芯能级X射线发射光谱（VTC-XES），对一系列铂镍合金进行价带中铂5d态密度的实验检测。VTC-XES测量结果表明，稀释时铂d带中心远离费米能级，同时铂d带宽度呈现浓度依赖性。首次通过实验观察到应变效应和配体效应之间的竞争。结果发现，由于压缩应变过度补偿了稀释效应，PtNi和PtNi中的d带宽度比铂金属的更宽，而在配体效应占主导的PtNi中d带宽度更窄。VTC-XES被证明是研究铂d带对铂基金属双原子价带贡献的有力工具。讨论了铂镍催化剂在氧还原反应中活性增强的意义。
Zotero 插件