Electrochemical behavior of hydride ion in a LiF-NaF-KF eutectic melt

The electrochemical behavior of hydride ion on a nickel electrode in a LiF- NaF-KF eutectic melt at 773 K has been studied by means of gas chromatograp hy, cyclic voltammetry, chronopotentiometry and chronoamperometry. It was f ound that hydride ion is anodically oxidized at around 0.45 V vs. M+ / M (M = alkali metal) and pure hydrogen gas is generated according to the follow ing reaction: H- --> 1/2 H-2+e(-) This anodic process is a reversible, one-electron reaction governed by diff usion transport. The diffusion coefficient of hydride ion, DH-, was estimat ed to be around 1x10(-5) cm(2) s(-1) at 773 K.