295-299The electrochemical adsorption and
diffusion (dissolution) of hydrogen into mercury have been studied by the
methods of cyclic voltammetry and impedance spectroscopy. In the potential
range of -0.15 to -1.5 V (vs. Ag/AgCl) two peaks at -0.4 and -0.8 V have been
observed and are associated with the adsorption and absorption of hydrogen. Impedance
studies exhibit two overlapping semi-circles terminating in a straight line in
the low
potential region. The size of the
semi-circles increases as the potential is raised and is attributed to the
increased resistive effect of the dissolved hydrogen. The value of the real
component upon increasing the measurement potential to -0.9 V is followed by a
sharp decrease at higher potential and indicate the removal of the adsorbed as
well as adsorbed hydrogen atoms through the HER routes