Dehydrogenation properties of La-doped NaAlH4 (001) surface: A first-principle approach

First-principles calculations based on density functional theory have been performed to study the effects of La atom on the structural, electronic, and dehydrogenation properties of NaAlH4 (001) surface. A LaAl4H18 complex structure is found in the La atom doped NaAlH4 (001) surface. Two new peaks are imported into the density of state of La-doped NaAlH4 (001) surface at −1.46 and Fermi level due to the effect of La d orbitals. The analyses of bond length and electronic properties show that it is favorable to form LaAl phase. The average hydrogen removal energy of La-doped NaAlH4 (001) surface decreases to 2.390 eV, which is smaller than that of pristine NaAlH4 (001) surface. The characteristic illustrates that doping La favors the dehydrogenation reaction of NaAlH4. The improved dehydrogenation in the La-doped NaAlH4 (001) surface may be attributed to the weakening of Al–H bond.