VOLTAMETRIC BEHAVIOR OF TINO2N-1 CERAMIC ELECTRODES CLOSE TO THE HYDROGEN EVOLUTION REACTION

Voltammetric behaviour close to the hydrogen evolution reaction has be en studied on metallic conducting oxides from TinO2n-1 series with n = 4-6. The Ti4O7, Ti5O9 and Ti6O11 ceramic electrodes were prepared by the reduction of TiO2 compacts with hydrogen. The current-voltage curv es (i, E) were obtained by the potentiodynamic method in aqueous solut ions. The electrochemical reaction which occurs in the cathodic potent ial region is discussed in terms of proton insertion into the TinO2n-1 structure. The influence of the porosity of the ceramic electrodes on the electrochemical reaction taking place in this potential region wa s examined using electrodes of different pore size distributions (diff erent values of roughness factor, r). The influence of the degree of r eduction of titanium oxide (n in TinO2n-1) on the electrolytic activit y for the hydrogen evolution reaction on these oxides was examined.