Acta Phys. -Chim. Sin. ›› 2011, Vol. 27 ›› Issue (08): 1816-1822.doi: 10.3866/PKU.WHXB20110814

• THEORETICAL AND COMPUTATIONAL CHEMISTRY • Previous Articles     Next Articles

Adsorption and Migration of Pt Atoms on γ-Al2O3(001) Surface

YAO Shu-Juan1, SHAO Xin1, CUI Shou-Xin2, ZHAO Jian-Wei1, ZHOU Cheng-Gang3   

  1. 1. College of Materials Science and Engineering, Liaocheng University, Liaocheng 252059, Shandong Province, P. R. China;
    2. School of Physics Science and Information Technology, Liaocheng University, Liaocheng 252059, Shandong Province, P. R. China;
    3. Sustainable Energy Laboratory, China University of Geosciences, Wuhan 430074, P. R. China
  • Received:2011-03-26 Revised:2011-05-20 Published:2011-07-19
  • Contact: ZHOU Cheng-Gang E-mail:cgzhoux@gmail.com
  • Supported by:

    The project was supported by the Start-up Fund of Doctor of Liaocheng University, China.

Abstract:

We present a systematic study using density functional theory (DFT) with the generalized gradient approximation (GGA) method to understand the adsorption and migration of Pt atoms on the γ-Al2O3(001) surface. Energetically the most favorable adsorption sites were identified and all these adsorption configurations were found to show substantial structural relaxation. Our calculated adsorption and energy barrier of migration results indicate that the Pt clusters can be stably anchored onto the surface. A significantly higher adsorption energy at the O site is largely attributed to the fact that charge transfer from Pt to O atoms results in positively charged Pt atoms. The repulsion between Pt and Al atoms leads to much weaker bonds. The calculated average adsorption energies were found to be size and shape dependent and in general decrease as the number of Pt atoms increases. The highest energy barrier for Pt atom migration on the γ-Al2O3(001) surface is about 0.51 eV. The formation of a metal cluster would be strongly preferred upon high Pt atom loading. Consequently, the evolution of Pt atoms on the γ-Al2O3(001) surface is unlikely to be smooth and agglomeration can occur under certain conditions.

Key words: Density functional theory, γ-Al2O3(001) surface, Pt atom, Adsorption energy, Migration

MSC2000: 

  • O641