Study of hydrogen diffusion and absorption in nickel by the electrochemical permeation and desorption method

Diffusion and absorption of hydrogen in thin nickel membranes, cathodically charged with hydrogen in NaOH solution, were studied by the electrochemical permeation and desorption method. First, the diffusion coefficient of hydrogen was determined on the basis of the permeation build-up and decay transients. Then, the analysis of the desorption rate of hydrogen at both sides of the previously charged membrane enabled the determination of amounts of the diffusible and reversibly trapped hydrogen and their distribution in the membrane. Most probably, the reversibly trapped hydrogen originated mainly from nickel hydride forming beneath the membrane surface.