Thermodynamic analysis of (bi)sulphate adsorption on a Pt(111) electrode as a function of pH

摘要: Abstract A complete thermodynamic study of (bi)sulphate adsorption on Pt(1 1 1) electrodes from solutions at four different pHs (pH 0.43, 2.1, 3.1 and 4.1) is reported. The effect pH the sum Gibbs excesses sulphate bisulphate species, standard energies formal partial charge numbers analyzed. results provide relevant information nature species involved in voltammetric features. experiments 0.43 were performed a higher base electrolyte concentration (0.5 M), that allows broader range concentrations. Under these conditions, two steps are clearly defined, associated to features, between 0.30 0.60 V 0.65 0.90 V (standard hydrogen scale, SHE). Once increased, marked decrease absolute value energy observed, concomitant with an increasing amount OH co-adsorption.