Adsorption and reduction of palladium–dimethylglyoxime complex

Abstract The voltammetric reduction of Pd II (DMGH) 2 preadsorbed on mercury in 0.2 M acetic/acetate buffer (pH 4.85) was studied. Two adsorbed surface stages could be distinguished: while a submonolayer is present molecules adsorb parallel to the electrode, but at high surface concentration perpendicular interactions between adsorbed molecules lead to bilayer or even multilayer formation. The surface charge value obtained for the reduction of a virtual monolayer is Q M  = 38 μC cm −2 . The electrochemical behaviour of adsorbed species under submonolayer coverage is explained in terms of an E r C i surface reaction scheme and a rate expression that takes into account attractive forces between the adsorbed reactant complex molecules.