The kinetics of hydrogen evolution reaction accompanied by hydrogen absorption reaction with consideration of subsurface hydrogen as an adsorbed species: Polarization curve

The scheme for hydrogen evolution reaction with hydrogen absorption in parallel is considered using the concept of hydrogen adsorbed in the subsurface. The steady-state polarization curves are calculated for cases when hydrogen evolution occurs according to the Volmer–Heyrovsky and Volmer–Tafel mechanisms with the Langmuir hydrogen adsorption isotherm. It is shown that at low current densities, j, the presence of hydrogen absorption results in an increase in the slopes dη/dlnj (η is the overpotential).