INFLUENCE OF PERFLUORINATED AND HYDROGENATED SURFACTANTS UPON HYDROGEN EVOLUTION ON GOLD ELECTRODES

The influence of perfluorinated and hydrogenated surfactants on the me chanism of hydrogen evolution on gold electrodes in 1 M H2SO4 has been investigated from steady-state polarization curves and impedance data . The ohmic drop due to bubbles and the reaction inhibition, consequen t on both the electrode surface masking by bubbles and the surfactant adsorption, have been separated and compared. The activity of surfacta nts decreases with the hydrophilic head in the order cationic > anioni c > nonionic. Perfluorinated surfactants produce a lower inhibition th an the hydrogenated ones on the electrochemical reaction which occurs in a Tafel kinetic regime, independently of the presence of surfactant s.