Effect of the preceding chemical reaction on the hydrogen electrode reaction in molten ethylammonium tetrafluoroborate

The hydrogen evolution reaction (HER) on platinum electrode in pure molten ethylammonium tetrafluoroborate (EABF(4)) has been investigated using a.c. impedance and potentiostatic steady-state polarization technique. The recor ded impedance spectra have been discussed by an equivalent circuit approach and the theory of impedance of a quasi reversible electrode process preced ed by a chemical (dissociation) reaction. The exchange current density of t he HER, its activation energy, the diffusion coefficient of the hydrogen ca tion and the forward and backyard rate constants of the preceding dissociat ion of ethylammonium cation have been determined.