Carbon-induced corrosion of nickel anode

In high-temperature solid oxide fuel cells where natural gas is used as a fuel, high-carbon-activity environments can be encountered in the anode compartment. Under these conditions, nickel could corrode by a process known as metal dusting. In the present study, metal dusting corrosion of pure nickel is simulated in high-carbon-activity environments at temperatures between 350 and 1050 degrees C. The focus of this research is to understand reaction mechanisms by characterizing interfacial processes at the nanometer level. Nickel corrodes by a combination of carbon diffusion and precipitation in the bulk metal and atom migration through surface carbon deposits. The nature of the carbon deposit is important in the overall corrosion process. At lower temperatures closer to about 350 degrees C, nickel forms a carbide. Ni3C, which is rather stable and does not decompose. (C) 2000 The Electrochemical Society. S0013-4651(00)01-041-7. All rights reserved.