Release behavior of hydrogen isotopes in Li 2 TiO 3 pellet

Release behavior of hydrogen isotopes thermally sorbed in Li2TiO3 pellet was studied by thermal desorption spectroscopy (TDS). As microstructure (grain size, surface condition, open and closed pores) of pellet samples were changed by high-temperature sintering, the release behavior of hydrogen isotopes was changed. The amount of hydroxyl groups chemically adsorbed on the surface was found to increase with the specific surface area. The gas migration in open pores was delayed to high temperature region (450~650 K), for which Knudsen diffusion and interaction between gas molecules and walls of narrow open pore channels is considered to be the main mechanism. The release of hydroxyl groups absorbed in the bulk was delayed due to the existence of closed pores, and these hydroxyl groups have to undergo bulk diffusion and trapping in closed pores several times before desorption.