Parametrization of a reactive force field for aluminum hydride

Journal Article · Tue Jul 28 00:00:00 EDT 2009 · Journal of Chemical Physics

DOI:https://doi.org/10.1063/1.3182853· OSTI ID:21559753

Ojwang, J G. O. ^[1]; Santen, Rutger A. van; Kramer, Gert Jan ^[1]; Duin, Adri C. T. van ^[2]; Goddard, III, William A ^[3]

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1. Schuit Institute of Catalysis, Eindhoven University of Technology, Postbus 513, Den Dolech 2, Eindhoven 5600 MB (Netherlands)
2. Department of Mechanical and Nuclear Engineering, Pennsylvania State University, University Park, Pennsylvania 16802 (United States)
3. Materials and Process Simulation Center (MSC), California Institute of Technology, 1200 East California Boulevard, Pasadena, California 91125 (United States)

A reactive force field, REAXFF, for aluminum hydride has been developed based on density functional theory (DFT) derived data. REAXFF{sub AlH{sub 3}} is used to study the dynamics governing hydrogen desorption in AlH{sub 3}. During the abstraction process of surface molecular hydrogen charge transfer is found to be well described by REAXFF{sub AlH{sub 3}}. Results on heat of desorption versus cluster size show that there is a strong dependence of the heat of desorption on the particle size, which implies that nanostructuring enhances desorption process. In the gas phase, it was observed that small alane clusters agglomerated into a bigger cluster. After agglomeration molecular hydrogen was desorbed from the structure. This thermodynamically driven spontaneous agglomeration followed by desorption of molecular hydrogen provides a mechanism on how mobile alane clusters can facilitate the mass transport of aluminum atoms during the thermal decomposition of NaAlH{sub 4}.

• OSTI ID: 21559753
• Journal Information: Journal of Chemical Physics, Vol. 131, Issue 4; Other Information: DOI: 10.1063/1.3182853; (c) 2009 American Institute of Physics; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
ADSORPTION HEAT
AGGLOMERATION
ALUMINIUM
ALUMINIUM HYDRIDES
ATOMS
CHARGE EXCHANGE
DENSITY FUNCTIONAL METHOD
DESORPTION
HYDROGEN
NANOSTRUCTURES
PARTICLE SIZE
PARTICLES
PYROLYSIS
REACTION KINETICS
SURFACES
ALUMINIUM COMPOUNDS
CALCULATION METHODS
CHEMICAL REACTIONS
DECOMPOSITION
ELEMENTS
ENTHALPY
HYDRIDES
HYDROGEN COMPOUNDS
KINETICS
METALS
NONMETALS
PHYSICAL PROPERTIES
SIZE
SORPTION
THERMOCHEMICAL PROCESSES
THERMODYNAMIC PROPERTIES
VARIATIONAL METHODS