Nn. Vershinin et Nn. Aleinikov, ELECTRODE-POTENTIALS IN THE SYSTEM SOLID FLUORINE-CONDUCTING ELECTROLYTE-NICKEL OXYFLUORIDE-PLATINUM-CARBON MONOXIDE, Russian journal of electrochemistry, 31(6), 1995, pp. 570-576
Behavior of electrochemical cells with a solid fluorine-conductin,o el
ectrolyte based on PbF2 is investigated in a gaseous environment compo
sed of air and CO (the CO concentration in the interval 10(-5) to 10 v
ol %) at room temperature. Variations in the emf of the sensing electr
ode based on nickel oxyfluoride is connected with changes in the conce
ntration of electrons and holes. A theoretical model is proposed for o
xide ionic-electronic semiconductor electrodes that describes the depe
ndence of emf on the concentration of CO and H-2. The emf vs. log CO d
ependence in the region of p-type conduction of nickel oxyfluoride is
nonlinear, whereas in the region of n-type conduction, this dependence
is linear and has a slope close to the calculated value 55 - 60 mV. I
n the region corresponding to the transition from p-type conduction to
n-type conduction, emf is observed to sharply change, and the magnitu
de of the jump depends on the ratio between the concentration of ioniz
ed acceptors of the initial oxyfluoride and the concentration of elect
rons of stoichiometric nickel oxyfluoride.