On Pt-Rh alloy electrodes

the effect of some operational parameters on the adsorption process of several unsaturated aliphatic acids was respectively examined by fast cathodically potentiodynamic polarization. As the experimental results shown

the adsorption rates of acrylic acid

crotonic acid

and maleic acid

obey Rogynski-Zilidowicz equation always in the middle coverage .Comparatively

the maximal values are determined on the pure Pt-electrode

and as the electrode binary composition is varied successively from the pure Pt to Rh

the adsorption rates for these acids are generally decreased

even by 20～30 times. Among the three unsaturated aliphatic acids

acrylic acid is most advantageously adsorbed on the electrode surfaces. The adsorption activity order is acrylic acid >crotonic acid>maleic acid.