Formation and bonding of alane clusters on Al(111) surfaces studied by infrared absorption spectroscopy and theoretical modeling

Santanu Chaudhuri, Sylvie Rangan, Jean Francois Veyan, James Muckerman, Yves J. Chabal

Research output: Contribution to journalArticle

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Abstract

Alanes are believed to be the mass transport intermediate in many hydrogen storage reactions and thus important for understanding rehydrogenation kinetics for alanates and AIH3. Combining density functional theory (DFT) and surface infrared (IR) spectroscopy, we provide atomistic details about the formation of alanes on the Al(111) surface, a model environment for the rehydrogenation reactions. At low coverage, DFT predicts a 2-fold bridge site adsorption for atomic hydrogen at 1150 cm-1, which is too weak to be detected by IR but was previously observed in electron energy loss spectroscopy. At higher coverage, steps are the most favorable adsorption sites for atomic H adsorption, and it is likely that the AIH3 molecules form (initially strongly bound to steps) at saturation. With increasing exposures AIH 3 is extracted from the step edge and becomes highly mobile on the terraces in a weakly bound state, accounting for step etching observed in previous STM studies. The mobility of these weakly bound AIH3 molecules is the key factor leading to the growth of larger alanes through AIH3 oligomerization. The subsequent decomposition and desorption of alanes is also investigated and compared to previous temperature programmed desorption studies.

Original languageEnglish
Pages (from-to)10576-10587
Number of pages12
JournalJournal of the American Chemical Society
Volume130
Issue number32
DOIs
Publication statusPublished - Aug 13 2008

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Infrared absorption
Absorption spectroscopy
Adsorption
Infrared spectroscopy
Spectrum Analysis
Density functional theory
Hydrogen
Electron Energy-Loss Spectroscopy
Insemination, Artificial, Homologous
Oligomerization
Molecules
Electron energy loss spectroscopy
Hydrogen storage
Temperature programmed desorption
Etching
Desorption
Mass transfer
Infrared radiation
Decomposition
Kinetics

ASJC Scopus subject areas

  • Chemistry(all)

Cite this

Formation and bonding of alane clusters on Al(111) surfaces studied by infrared absorption spectroscopy and theoretical modeling. / Chaudhuri, Santanu; Rangan, Sylvie; Veyan, Jean Francois; Muckerman, James; Chabal, Yves J.

In: Journal of the American Chemical Society, Vol. 130, No. 32, 13.08.2008, p. 10576-10587.

Research output: Contribution to journalArticle

Chaudhuri, Santanu ; Rangan, Sylvie ; Veyan, Jean Francois ; Muckerman, James ; Chabal, Yves J. / Formation and bonding of alane clusters on Al(111) surfaces studied by infrared absorption spectroscopy and theoretical modeling. In: Journal of the American Chemical Society. 2008 ; Vol. 130, No. 32. pp. 10576-10587.
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