The study of electrochemical palladium behavior using the quartz crystal microbalance - II. Basic solutions

The electrochemical quartz crystal microbalance (EQCMB) method has been use d to evaluate the processes which occur in/on the palladium electrode in ba sic solutions. Hydrogen electrosorption in palladium is accompanied by an a dditional frequency shift that can be attributed to the stresses generated inside the Pd metal. A non-linear dependence between the mass change and th e charge consumed during hydrogen oxidation in the Pd electrode has been fo und for hydrogen absorbed in the alpha- and beta-phases. This effect preclu des the objective estimation of the amount of hydrogen absorbed inside the Pd electrode. The EQCMB method has been used, however, for studying the sur face electrode processes on the Pd electrode, i.e. specific anion adsorptio n, surface oxidation and dissolution. Also. the structure of the palladium oxide formed on the Pd surface during electrochemical oxidation is discusse d in this paper and the effect of the anodic limiting potential on the oxid e structure is reported.