T. Nishina et al., WATER EFFECT ON OXYGEN REDUCTION IN MOLTEN (LI+K)CO3 EUTECTIC, Journal of electroanalytical chemistry [1992], 408(1-2), 1996, pp. 181-187
The effect of water on electrode kinetics and mechanism of the oxygen
reduction at the fully immersed flag-type Au electrode in (62 + 38)mol
% (Li + K)CO3 melt at 650 degrees C have been investigated using the c
yclic voltammetry, electrochemical impedance spectroscopy (EIS) and th
e digital simulation of the single scan voltammograms. The cyclic volt
ammograms of the oxygen reduction under P-O2 : P-CO2 = 0.9:0.1 atm wit
h 2.9-15.4 Torr H2O vapor showed more reversible waves than those obta
ined under a dry atmosphere. The EIS spectra at the open circuit poten
tial for the oxygen reduction also showed distinctly reduced impedance
values in the presence of water. From the analysis of both the data,
it was found that the apparent mass transfer parameter C root D was in
creased by the presence of water, indicating that water can act as an
acid species in the neutralization reaction of the oxide ion according
to the reaction H2O + O2- reversible arrow 2OH(-).