Oxide-derived Pd electrodes were obtained by cathodic polarization of Pd oxide-coated titanium electrodes (fabricated by thermal decomposition) at 0 V (RHE) for 30 min in 1.5 mol dm(-3) NaOH. Hydrogen adsorption/absorption (denoted hereafter as sorption) and desorption within/at these electrodes were obtained using cyclic voltammetry (CV), chronopotentiometry, and linear sweep voltammetry (LSV). CV results revealed that beta-PdH formation/oxidation is more reversible in either concentrated acid or base solutions than in intermediate pH media and the rate of beta-PdH desorption is faster in a pH solution <10. The oxidation of beta-PdH is electron transfer controlled in intermediate pH media, especially in weakly basic solutions due to the adsorption of H2PO4-/HPO42-. The sequence of anions with respect to increasing ability to inhibit hydrogen sorption is : CH3COO- < Cl- < HSO4- similar or equal to ClO4- < HC2O4- < H2PO4-.