S. Gultekin et al., DEACTIVATION STUDIES ON THE POROUS NI-GAS DIFFUSION ELECTRODE IN H-2 O-2 ALKALINE FUEL-CELL/, International journal of hydrogen energy, 21(6), 1996, pp. 485-489
Citations number
8
Categorie Soggetti
Energy & Fuels","Environmental Sciences","Physics, Atomic, Molecular & Chemical
Long term performance tests were carried out potentiostatically for th
e Cu-impregnated Ni-gas diffusion electrode at Various temperatures. T
o measure the deactivation with time, the voltage between the working
electrode and the reference electrode was kept constant and the fall o
f current density (i.e. the reaction rate) was monitored as a function
of time. At almost every temperature there was a decay of activity. T
he higher the temperature the faster the observed deactivation rate wa
s. The deactivation model assumed a first order reactant-gas-concentra
tion-independent deactivation. The spherical flooded grain model was u
sed for the determination of the deactivation rate constants (k(d)s) a
t different conditions. Deactivation is attributed to: (a) dissolution
of promoter Cu and Ni, hence reducing the electronic contact; (b) for
mation of Ni(OH)(2) which passivates the electrode; (c) the change in
the hydrophobicity of PTFE; and (d) dissolution of atmospheric CO2 in
the KOH, forming K2CO3. Copyright (C) 1996 International Association F
or Hydrogen Energy.