Reaction order and activation energy for H-2, oxidation on Ni/3 mol.% Y2O3-ZrO2 (Ni/Y-TZP) cermet electrodes have been evaluated by galvanostatic current interruption (GCI) and electrochemical impedance spectroscopy (EIS) techniques. GCI data show a reaction order in P-H2O of 0.4 and activation energy of 76 kJ mol(-1). In contrast, a first order with respect to P-H2O and an activation energy of 169 kJ mol(-1) are obtained from EIS data. During GCI measurements, the actual H2O content or P-H2O/P-H2 ratio at the electrode/electrolyte interface region could be significantly higher than that in the bulk electrode as H2O, the product of the reaction, remains in the gas phase. On the other hand, the H2O content at the interface region is very close to that in the bulk during EIS measurements under open circuit, It has been shown that H2O produced at the interface region during GCI measurements enhances the H, oxidation reaction, resulting in the shifting of the reaction rate dependency on H2O and activation energy to lower values as compared to those measured by EIS,