Thick film cermet of ZrO2-Y2O3-TiO2/Ni:: Anodic polarization study

Thick films of [(ZrO2)(0.92)(Y2O3)(0.08)](0.9)(TiO2)(0.1)/Ni (35 vol%) have been deposited onto yttria stabilized zirconia (YSZ) substrates. The cermets were prepared by mixing a YSZ commercial powder, TiO2, NiO and a controlled amount of carbon. Thixotropic slips with a solids content of 60 wt% were obtained. After sintering at 1300 degrees C in air, without introduction any reducing atmosphere, the thick film cermets show goad adherence and chemical and mechanical compatibility with YSZ electrolyte. The hydrogen oxidation on the cermets, using a three-electrode cell, has been studied. The polarization resistance is consisted of two separated contributions, one might be associated to the typical proton charge transfer, and the second one, might be originated from the adsorption reaction of electroactive species. The anodic polarization curve exhibited a maximum of current density for an overpotential close to that of the Ni-NiO system, which could be associated to the oxidation of hydrogen on NiO. (C) 1998 Published by Elsevier Science Limited. All rights reserved.