State of H species sorption at Fe-containing glassy-metal electrodes during the hydrogen evolution reaction

摘要

Continuing the examination of the electrochemical behaviour of glassy metal alloys as possible electrocatalysts for cathodic hydrogen production in water electrolysis, three Fe-containing glassy electrodes have been examined, especially in regard to the state of H species sorption during the H_2 evolution reaction. The possible role of the state of sorbrd H as a three-dimensional hydride formed on the surface region, indicated before in HER at Ni-containing glassy metal electrodes, is extended to Fe-containing glassy metal electrodes. The sorption behaviour of the H species is evaluated from digitally acquired open-circuit potential-decay transients and steady state polarization measurements, which enable the H pseudocapacitance to be derived over a range of H_2 evolution potentials. Transfer coeffiecnts and Tafel slopes have been determined from the polarization behaviour and the possibility of changes in the reaction mechanism with potential are discussed.