First-principles study of Ti-doped sodium alanate surfaces -: art. no. 103109

We have performed first-principles calculations of thick slabs of Ti-doped sodium alanate (NaAlH4), which allows one to study the system energetics as the dopant progresses from the surface to the bulk. Our calculations predict that Ti stays on the surface, substitutes for Na, and attracts a large number of H atoms to its vicinity. Molecular dynamics simulations suggest that the most likely product of the Ti doping is the formation of H-rich TiAln(n > 1) compounds on the surface, and hint at the mechanism by which Ti enhances the reaction kinetics of NaAlH4. (c) 2005 American Institute of Physics.