In this study an attempt is made to produce nickel-niobium alloy films on nickel surface by an electrochemical process in molten fluoride. An investigation of the electrochemical behaviour of niobium ions in NaF-CaF_2-K_2NbF_7 system has been conducted the following conclusions were drawn: The early stage of metal deposition is controlled by an instantaneous nucleation process, and higher applied potential is beneficial to the increase of the density of niobium nuclei. Thus a better quality of niobium coating can be obtained. The niobium-modified niclel electrode is used as MCFC anode; and the composite oxide formed by the preoxidation of Ni-Nb surface alloy is used as MCFC cathode. Some polarization experiments prove that corrosion resistance as well as electrocatalytic activity of the niobium-modified anode is superior than that of an unmodified one. The preoxidised Ni-Nb surface alloy is more stable than NiO cathode. Furthemore, the tests for electrocatalytic activity indicate that preoxidation Ni-Nb surface alloy is more effect than NiO on catalysis to the reduction of oxyge.
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