材料期刊网

First-principles calculations were performed to determine the equilibrium crystal structures, energetic properties, and stability of Mg(x)Ti((1-x))H(2) (x=0.25, 0.5, 0.75, 0.875) systems containing different amounts of titanium using the pseudopotential plane-wave method based on density functional theory. The calculation results show that the hydrogen atoms in the Mg(x)Ti((1-x))H(2) hydrides roughly occupy the tetrahedral interstitial sites. The calculated H Ti distances are less than the H Mg distances. This indicates that Ti has a more notable affinity for hydrogen than Mg. The bonding strength of H Mg is weaker when the Ti atom attracts surrounding hydrogen atoms. The stabilization and dehydrogenation temperatures of the hydrides Mg(x)Ti((1-x))H(2) are lower than those of MgH(2) with an increasing Ti content. This indicates that titanium can reduce the decomposition temperature of the Mg(x)Ti((1-x))H(2) hydrides and play a significant catalytic role in improving the dehydrogenation dynamic properties of the Mg(x)Ti((1-x))H(2) hydrides.