Out-of-cell measurements of H 2–H 2O effective binary diffusivity in the porous anode of solid oxide fuel cells (SOFCs)

Abstract

The effective binary diffusivity of H 2 and H 2O in a Ni and yittria-stabilized zirconia (YSZ) anode of the solid oxide fuel cells (SOFCs) was measured between 650 and 800 °C using an electrochemical cell consisting of an oxygen pump, an oxygen sensor, and a porous SOFC anode pellet. The effective binary diffusivity was obtained from the relationship between the current density across the oxygen pump, and the H 2 partial pressure gradient across the anode sample measured using the oxygen sensor. The anode limiting current density and concentration polarization were estimated using the experimental results.