First-Principles Study of the Effect of Doped Metal Atoms Pd, Mg and Ti on Tritium Release from Li2O (111) Surface

Abstract In this study, the effect of doped metal atoms Pd, Mg and Ti on the release of tritium on the Li2O (111) surface is studied by using density functional theory. On the clean Li2O (111) surface, the formation energies of T2O and T2 are 3.41 eV and 6.30 eV, respectively. About the Li2O (111) surface doped with Pd, Mg and Ti, the T2O molecule are formed spontaneously, and the desorption energies are 1.26, 0.58 and 0.18 eV, respectively. The formation energy of T2 molecule is 2.83 eV, on the surface of Ti-doped Li2O (111). By analyzing Bader charge, charge density difference (CDD), local density of state (LDOS) and the formation energy of oxygen vacancy, we found that dopants can affect the interaction of surrounding atoms through charge transfer and reduce the O vacancy formation energy, and then generate the desorption sites with low activation energy, thereby promoting the formation and desorption of T2O or T2. In a word, doping Pd, Mg and Ti on the Li2O (111) surface can catalyze the release of tritium.