The Use of Large Anodic Galvanostatic Transients to Evaluate the Maximum Adsorption on Pt from Hcooh Solutions

摘要

The adsorption on smooth Pt. from HCOOH solutions in 1N HC104 at 40 C has been studied with anodic and cathodic galvanostatic transients. During the application of a large anodic current, Ia, three processes contribute to the charge passed, Qa. These are: (I) oxidation of adsorbate, (II) oxidation of a species in solution, and (III) surface oxidation of the electrode. By applying a cathodic current, Ic, at various times during the anodic transient, it is possible to measure (III) directly and, from the charge passed in deposition of H-atoms prior to H2 evolution, one can follow changes in the concentration of absorbed HCOOH. By varying In, one can assess the effect of (II). It is found that the contributions of processes (I), (II), and (III) can be effectively separated. (Author)