Strain and ligand effects in Pt-Ni alloys studied by valence-to-core X-ray emission spectroscopy

Jiatang Chen; Y. Zou Finfrock; Zhiqiang Wang; Tsun-Kong Sham

doi:10.1038/s41598-021-93068-0

Scientific Reports (Jul 2021)

Strain and ligand effects in Pt-Ni alloys studied by valence-to-core X-ray emission spectroscopy

Jiatang Chen,
Y. Zou Finfrock,
Zhiqiang Wang,
Tsun-Kong Sham

Affiliations

Jiatang Chen: Department of Chemistry, University of Western Ontario
Y. Zou Finfrock: CLS@APS Sector 20, Advanced Photon Source, Argonne National Laboratory
Zhiqiang Wang: Department of Chemistry, University of Western Ontario
Tsun-Kong Sham: Department of Chemistry, University of Western Ontario

DOI: https://doi.org/10.1038/s41598-021-93068-0
Journal volume & issue: Vol. 11, no. 1
pp. 1 – 8

Abstract

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Abstract 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 L3-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 Pt3Ni and PtNi are broader than that of Pt metal due to compressive strain which overcompensates the effect of dilution, while it is narrower in PtNi3 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.

Published in Scientific Reports

ISSN: 2045-2322 (Online)
Publisher: Nature Portfolio
Country of publisher: United Kingdom
LCC subjects: Medicine; Science
Website: https://www.nature.com/srep/

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