Abstract
Density functional theory (DFT) calculations are performed for the adsorption energy of hydrogen and oxygen on graphene decorated with a wide set of metals (Li, Na, K, Al, Ti, V, Ni, Cu, Pd, Pt). It is found that oxygen interferes with hydrogen adsorption by either blocking the adsorption site or by the irreversible oxidation of the metal decoration. The most promising decorations are Ni, Pd, and Pt due to a reasonable relationship of adsorption energies which minimize the oxygen interference. The DFT results are used to parametrize a statistical mechanical model which allows evaluation of the effect of partial pressures in the gas phase during storage. According to this model, even in the most promising case, it is necessary to reduce the oxygen partial pressure close to ultrahigh vacuum conditions to allow hydrogen storage.
- Received 29 June 2011
DOI:https://doi.org/10.1103/PhysRevLett.107.158701
© 2011 American Physical Society
Synopsis
Keep Oxygen Out
Published 6 October 2011
Hydrogen storage on carbon materials is strongly affected by the presence of oxygen.
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