Catalysis Letters

, Volume 144, Issue 10, pp 1667–1673

Theoretical Study of Carbon Adsorption on Re Surfaces: Morphological Instability

  • Payam Kaghazchi
  • Timo Jacob
  • Xiaofang Yang
  • Grant Junno
  • Hao Wang
  • Wenhua Chen
  • Bruce E. Koel
  • Robert A. Bartynski
Article

DOI: 10.1007/s10562-014-1324-3

Cite this article as:
Kaghazchi, P., Jacob, T., Yang, X. et al. Catal Lett (2014) 144: 1667. doi:10.1007/s10562-014-1324-3

Abstract

We report results from new experiments on C/Re(\(11\bar{2}1\)) to identify threshold conditions for morphological instability of Re(\(11\bar{2}1\)). We have found that adsorption of carbon from 0.35 to 0.85 ML (0.3–6.0 L exposure of C2H2) at T ≥ 800 K leads to faceting of Re(\(11\bar{2}1\)) with formation of three-sided pyramids. Using density functional theory we have investigated binding sites and binding energies of C on planar and faceted Re surfaces as well as generated a surface phase diagram of C/Re to obtain an atomistic understanding of C-induced pyramidal faceting of Re(\(11\bar{2}1\)). The calculations reveal that at low to intermediate coverage, C atoms prefer binding at four-fold sites on the Re surfaces and formation of three-sided pyramids is thermodynamically favored.

Graphical Abstract

Using density functional theory and thermodynamic considerations as well as AES and LEED measurements we studied the structure of Re(11–21) surfaces in contact with C2H2. The experiments show that adsorption of carbon from 0.35 to 0.85 ML (0.3–6.0 L exposure of C2H2) at T ≥ 800 K leads to faceting of Re(11–21) with formation of three-sided pyramids. The calculations reveal that at low to intermediate coverage, C atoms prefer binding at four-fold sites on the Re surfaces and formation of three-sided pyramids is thermodynamically favored.

Keywords

Rhenium Faceting Carbon Surface morphology Surface phase diagram 

Copyright information

© Springer Science+Business Media New York 2014

Authors and Affiliations

  • Payam Kaghazchi
    • 1
  • Timo Jacob
    • 2
  • Xiaofang Yang
    • 3
  • Grant Junno
    • 4
  • Hao Wang
    • 4
  • Wenhua Chen
    • 4
  • Bruce E. Koel
    • 3
  • Robert A. Bartynski
    • 4
  1. 1.Institute for Chemistry and BiochemistryFree University BerlinBerlinGermany
  2. 2.Institute of ElectrochemistryUlm UniversityUlmGermany
  3. 3.Department of Chemical and Biological EngineeringPrinceton UniversityPrincetonUSA
  4. 4.Department of Physics and Astronomy, and Laboratory for Surface Modification, RutgersThe State University of New JerseyPiscatawayUSA

Personalised recommendations