Surface Modification of Ni-YSZ Using Niobium Oxide for Sulfur-Tolerant Anodes in Solid Oxide Fuel Cells

The surface of a dense Ni–yttria-stabilized zirconia (YSZ) anode for solid oxide fuel cells (SOFCs) was modified with niobium oxide in order to achieve sulfur tolerance. Results suggest that was reduced to under SOFC operating conditions, which has high electrical conductivity and catalytic activity toward hydrogen oxidation. The -coated dense Ni-YSZ cermet anode showed sulfur tolerance when exposed to at over . Raman spectroscopy and X-ray diffraction analysis suggest that different phases of niobium sulfides were formed on the surfaces of niobium oxides. Furthermore, density of state (DOS) analysis of , , and indicates that the electronic structure of niobium sulfides are similar to that of ; they are electrically conductive and catalytically active for hydrogen oxidation in containing fuels under the conditions studied.