Experimental Study of Electrochemical Deuterium Loading of Pd Cathodes in the LiOD/D2O System

Abstract The electrochemical loading behaviour of Pd cathodes in the LiOD/D 2 O system has been studied experimentally. The preparation conditions of Pd cathodes significantly affect the D/Pd loading ratios. In addition, the D/Pd ratio is affected by the current density profile, current increasing pattern and anodic treatments. The major treatments were (1) a vacuum annealing to release the stress, to recrystallise and to clean the surface by thermal etching, and (2) a surface treatment to remove surface defects and to clean the surface. It was concluded that higher annealing temperatures (∼1000 °C) result in a higher D/Pd ratio. In addition, etching in aqua regia proved to be a better surface treatment than polishing. It was confirmed that using the pre-electrolysis treatments resulted in higher D/Pd ratios. The electrolysis current pattern and anodic treatment cycles likewise affected the D/Pd ratio. The effects are also discussed in detail below.