AN INVESTIGATION OF THE HYDROGEN ABSORPTION REACTION INTO, AND THE HYDROGEN EVOLUTION REACTION FROM, A PD FOIL ELECTRODE

The hydrogen absorption reaction (har) into, and the hydrogen evolutio n reaction (her) from, Pd foil electrode have been investigated in 0.1 M NaOH solution by using electrochemical impedance spectroscopy. The generalised Faradaic admittance for the indirect har into, and her fro m, metal foil electrodes under the impermeable boundary conditions has been derived on the basis of Lim and Pyun's kinetic approach to har a nd her. The measured impedance spectra were analysed by using a comple x non-linear least squares data-fitting method applied to the derived Faradaic admittance. Also, impedance spectra were theoretically calcul ated with different kinetic parameters for the har and her having phys ical significance in order to characterise the influence of each kinet ic parameter on the change of the impedance spectra in the Pd foil ele ctrode.