A study of the electrochemical absorption and diffusion of hydrogen into mercury in acidic solution

Abstract

The 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.