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Influence of Carbon Vacancies on CO Chemisorption on TiC(001): A Theoretical Study

  • Received : 2016.10.10
  • Accepted : 2016.11.07
  • Published : 2017.02.20

Abstract

The extended $H{\ddot{u}}ckel$ method is employed to analyze the interaction of carbon monoxide with the TiC(001) surfaces, both perfect and containing carbon vacancies. CO exhibits a similar ${\sigma}$-donation interaction for both $Ti_{25}C_{25}$ and $Ti_{25}C_{23}$ clusters, as deduced from the fact that the populations of the CO $5{\sigma}$ orbital are identical upon adsorption, but it bonds more strongly with the $Ti_{25}C_{23}$ than with the $Ti_{25}C_{25}$ because the metal d electron density in $Ti_{25}C_{23}$ provides ${\pi}$ back-bonding interactions with CO that are absent in $Ti_{25}C_{25}$. This work suggests that a difference in reactivity toward CO of stoichiometric TiC and TiC with carbon defects is connected with the occupancy of $2{\pi}^*$ orbitals that leads to a significant weakening of the C-O bond.

Keywords

References

  1. (a) Levy, R. L.; Boudart, M. J. Science 1973, 181, 547. https://doi.org/10.1126/science.181.4099.547
  2. (b) Hwu, H. H.; Chen, J. G. Chem. Rev. 2005, 105, 185. https://doi.org/10.1021/cr0204606
  3. Oyama, S. T. The Chemistry of Transition Metal Carbides and Nitrides; Blackie Academic and Professional: Glasgow, U.K., 1996.
  4. Didziulis, S. V.; Butcher, K. D.; Perry, S. S. Inorg. Chem. 2003, 42, 7766. https://doi.org/10.1021/ic030140k
  5. Didziulis, S. V.; Frantz, P.; Fernandez-Torres, L. C.; Guenard, R. L.; El-bjeirami, O.; Perry, S. S. J. Phys. Chem. B 2001, 105, 5196. https://doi.org/10.1021/jp003249b
  6. Whangbo, M.-H.; Hoffmann, R. J. Am. Chem. Soc. 1978, 100, 6093. https://doi.org/10.1021/ja00487a020
  7. Whangbo, M.-H.; Hoffmann, R.; Woodward, R. B. Proc. R. Soc. A 1979, 366, 23. https://doi.org/10.1098/rspa.1979.0037
  8. Ren, J.; Liang, W.; Whangbo, M.-H. Crystal and Electronic Structure Analysis Using CAESAR; 1998. For details, see: http//www.PrimeC.com/.
  9. (a) Blyholder, G. J. Phys. Chem. 1964, 68, 2772. https://doi.org/10.1021/j100792a006
  10. (b) Saillard, J.-Y.; Hoffmann, R. J. Am. Chem. Soc. 1984, 106, 2006. https://doi.org/10.1021/ja00319a020
  11. Mant, B. P.; Asara, G. G.; Anderson, J. A.; Homs, N.; Ramirez de la Piscina, P.; Rodriguez, S.; Ricart, J. M.; Illas, F. Surf. Sci. 2013, 613, 63. https://doi.org/10.1016/j.susc.2013.03.005
  12. Asara, G. G.; Feria, L.; Florez, E.; Ricart, J. M.; Liu, P.; Rodriguez, J. A.; Illas, F. J. Phys. Chem. C 2011, 115, 22495. https://doi.org/10.1021/jp207770u