Surface segregation and oxidation of Pt3Ni(1 1 1) alloys under oxygen environment

H. C. Lee, B. M. Kim, C. K. Jeong, R. Toyoshima, H. Kondoh, T. Shimada, K. Mase, B. Mao, Z. Liu, H. Lee, Chuan Qi Huang, W. X. Li, P. N. Ross, B. S. Mun

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13 Citations (Scopus)

Abstract

Utilizing ambient pressure X-ray photoelectron spectroscopy (AP-XPS), the surface segregation and oxidation of Pt3Ni(1 1 1) alloys are investigated as a function of temperature and oxygen pressure. The in situ AP-XPS measurements of oxygen oxidation process show that the Pt "skin" surface is not stable under the exposure of oxygen pressure of 100 mTorr at room temperature. As the temperature and pressure are elevated, the formations of Ni2O3, NiOx, and NiO are observed on surface while Pt atom starts to reduce its adsorbed oxygen, which is a clear sign of surface segregation of Ni to surface. Upon the evacuation of oxygen gas, i.e. ultrahigh vacuum condition, both of NiOx and NiO oxide get reduced and Ni2O3 remains on the surface. The DFT calculation is employed to explain the formation of surface oxides under oxidation condition.

Original languageEnglish
Pages (from-to)3-7
Number of pages5
JournalCatalysis Today
Volume260
DOIs
Publication statusPublished - 2016 Feb 1

Keywords

  • Ambient pressure XPS
  • DFT
  • Metal oxidation
  • Pt alloys
  • Surface segregation

ASJC Scopus subject areas

  • Catalysis
  • Chemistry(all)

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    Lee, H. C., Kim, B. M., Jeong, C. K., Toyoshima, R., Kondoh, H., Shimada, T., Mase, K., Mao, B., Liu, Z., Lee, H., Huang, C. Q., Li, W. X., Ross, P. N., & Mun, B. S. (2016). Surface segregation and oxidation of Pt3Ni(1 1 1) alloys under oxygen environment. Catalysis Today, 260, 3-7. https://doi.org/10.1016/j.cattod.2015.05.003