Parametrization of a reactive force field for aluminum hydride.

A reactive force field, REAXFF, for aluminum hydride has been developed based on density functional theory (DFT) derived data. REAXFF(AlH(3)) is used to study the dynamics governing hydrogen desorption in AlH(3). During the abstraction process of surface molecular hydrogen charge transfer is found to be well described by REAXFF(AlH(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(4).

[1]  A. V. van Duin,et al.  Predictions of melting, crystallization, and local atomic arrangements of aluminum clusters using a reactive force field. , 2008, The Journal of chemical physics.

[2]  G. Kramer,et al.  An ab initio study of possible pathways in the thermal decomposition of NaAlH4 , 2008 .

[3]  M. Conradi,et al.  Molecular H2 trapped in AlH3 solid , 2008 .

[4]  A. V. van Duin,et al.  Modeling the sorption dynamics of NaH using a reactive force field. , 2008, The Journal of chemical physics.

[5]  M. Fichtner,et al.  Thermal decomposition of AlH3 studied by in situ synchrotron X-ray diffraction and thermal desorption spectroscopy , 2007 .

[6]  M. Sørby,et al.  In Situ Synchrotron Powder X-ray Diffraction Studies of the Thermal Decomposition of - and ?-AlD3 , 2007 .

[7]  J. Graetz,et al.  Thermodynamics of the a , and ? polymorphs of AlH 3 , 2006 .

[8]  G. Sandrock,et al.  Alkali metal hydride doping of α-AlH3 for enhanced H2 desorption kinetics , 2006 .

[9]  R. Maxwell,et al.  Al27 and H1 MAS NMR and Al27 multiple quantum studies of Ti-doped NaAlH4 , 2006 .

[10]  Oliver Kircher,et al.  Effects of catalysts on the dehydriding of alanates monitored by proton NMR , 2005 .

[11]  Jason Graetz,et al.  Decomposition kinetics of the AlH3 polymorphs. , 2005, The journal of physical chemistry. B.

[12]  A. Kuwabara,et al.  Cubic and orthorhombic structures off aluminum hydride AlH3 predicted by a first-principles study , 2005 .

[13]  G. Sandrock,et al.  Accelerated thermal decomposition of AlH3 for hydrogen-fueled vehicles , 2005 .

[14]  A. V. van Duin,et al.  ReaxFF(MgH) reactive force field for magnesium hydride systems. , 2005, The journal of physical chemistry. A.

[15]  R. T. Walters,et al.  A reversible hydrogen storage mechanism for sodium alanate: the role of alanes and the catalytic effect of the dopant , 2004 .

[16]  V. Ozoliņš,et al.  Hydrogen in aluminum: First-principles calculations of structure and thermodynamics , 2004 .

[17]  A. V. Duin,et al.  Adhesion and nonwetting-wetting transition in the Al/alpha-Al_2O_3 interface , 2004 .

[18]  A. V. van Duin,et al.  Shock waves in high-energy materials: the initial chemical events in nitramine RDX. , 2003, Physical review letters.

[19]  Xuefeng Wang,et al.  Infrared spectra of aluminum hydrides in solid hydrogen: Al2H4 and Al2H6. , 2003, Journal of the American Chemical Society.

[20]  Qiang Sun,et al.  Cyclic and linear polymeric structures of AlnH3n (n=3?7) molecules , 2003 .

[21]  A. V. Duin,et al.  ReaxFFSiO Reactive Force Field for Silicon and Silicon Oxide Systems , 2003 .

[22]  G. Sandrock,et al.  Catalyzed Complex Metal Hydrides , 2002 .

[23]  A. V. Duin,et al.  ReaxFF: A Reactive Force Field for Hydrocarbons , 2001 .

[24]  G. Seifert,et al.  AlH3 and Al2H6 : magic clusters with unmagical properties , 2001 .

[25]  G. Henkelman,et al.  A climbing image nudged elastic band method for finding saddle points and minimum energy paths , 2000 .

[26]  G. Henkelman,et al.  Improved tangent estimate in the nudged elastic band method for finding minimum energy paths and saddle points , 2000 .

[27]  K. Gross,et al.  In-situ X-ray diffraction study of the decomposition of NaAlH4 , 2000 .

[28]  E. Go,et al.  H adsorption and the formation of alane oligomers on Al(111) , 1999 .

[29]  R. Stumpf.  H-INDUCED RECONSTRUCTION AND FACETING OF AL SURFACES , 1997 .

[30]  Wang,et al.  Generalized gradient approximation for the exchange-correlation hole of a many-electron system. , 1996, Physical review. B, Condensed matter.

[31]  Burke,et al.  Generalized Gradient Approximation Made Simple. , 1996, Physical review letters.

[32]  Kresse,et al.  Efficient iterative schemes for ab initio total-energy calculations using a plane-wave basis set. , 1996, Physical review. B, Condensed matter.

[33]  Blöchl,et al.  Projector augmented-wave method. , 1994, Physical review. B, Condensed matter.

[34]  Jackson,et al.  Atoms, molecules, solids, and surfaces: Applications of the generalized gradient approximation for exchange and correlation. , 1992, Physical review. B, Condensed matter.

[35]  H. Schaefer,et al.  The known and unknown group 13 hydride molecules M2H6: Diborane(6), dialane(6), and digallane(6) , 1992 .

[36]  D. Brenner,et al.  Empirical potential for hydrocarbons for use in simulating the chemical vapor deposition of diamond films. , 1990, Physical review. B, Condensed matter.

[37]  Roberto Dovesi,et al.  Ab initio approach to molecular crystals: A periodic Hartree–Fock study of crystalline urea , 1990 .

[38]  K. Lammertsma,et al.  Ab initio study on dialane(6) and digallane(6) , 1990 .

[39]  M. Punkkinen,et al.  Low-temperature 1H NMR spectra of AlH3 , 1990 .

[40]  J. Tersoff,et al.  Empirical interatomic potential for carbon, with application to amorphous carbon. , 1988, Physical review letters.

[41]  H. Berendsen,et al.  Molecular dynamics with coupling to an external bath , 1984 .

[42]  H. Hjelmberg.  Hydrogen chemisorption on Al, Mg and Na surfaces — calculation of adsorption sites and binding energies , 1979 .

[43]  C. B. Roberts,et al.  Preparation and properties of aluminum hydride , 1976 .

[44]  H. Monkhorst,et al.  SPECIAL POINTS FOR BRILLOUIN-ZONE INTEGRATIONS , 1976 .

[45]  D. R. Stull,et al.  Thermodynamic Properties of Aluminum Hydride , 1967 .

[46]  V. Tarasov,et al.  NMR STUDY OF THERMAL DECOMPOSITION OF LITHIUM TETRAHYDROALUMINATE , 1997 .

[47]  G. Kirakosyan,et al.  LATTICE VIBRATIONS AND BARRIERS TO HINDERED ROTATION IN SODIUM TETRAHYDROALUMINATE AND TETRADEUTEROALUMINATE AS DETERMINED BY NMR , 1997 .

[48]  B. Bulychev,et al.  The P,T-State Diagram and Solid Phase Synthesis of Aluminum Hydride , 1995 .

[49]  Wilfried J. Mortier,et al.  Electronegativity-equalization method for the calculation of atomic charges in molecules , 1986 .

[50]  M. Tkacz,et al.  The Equilibrium Between Solid Aluminium Hydride and Gaseous Hydrogen , 1983 .

[51]  J. W. Turley,et al.  Crystal structure of aluminum hydride , 1969 .