OXYGEN ADSORPTION AND ELECTROCATALYSIS ON GOLD IN ALKALINE MEDIUM: STATE OF THE PROBLEM
Keywords:
gold, oxygen adsorption, phase oxides of gold, electrocatalysis, interference of the partial electrode reactions, aqueous alkaline medium, glycine anion, electrooxidation kinetics, voltammetry, chronoamperometry, in situ FTIR spectroscopy.Abstract
The phenomenological, microscopic, and structure-morphological aspects of the adsorption
of atomic oxygen, as well as the initial stages of the oxide generation and phase oxides formation on
the electrodes of polycrystalline and monocrystalline gold are considered. The question about the
sources and forms of oxygen adsorbed on gold is raised. The available data on the charge distribution
in the adsorption system Au-OH- with formation of mono- and biradical forms of oxygen are analyzed.
The particular attention is paid to the structure- and size-dependent electrocatalytic effects
observed on gold, as well as the role of potential, pH, and the electrode surface state. The diagnostic
possibilities of the linear voltammetry in the study of the kinetics of electrode processes complicated
by adsorption steps are discussed. The specifics of electrocatalytic reactions on gold in aqueous alkaline
medium due to coadsorption of the reactants and intermediates with atomic oxygen is also
discussed. As an example, the interdependent processes of adsorption and anodic oxidation of glycine
anion at potentials, precluding the possibility of the gold dissolution are considered.
