Development of anodes for direct oxidation of methane fuel in solid oxide fuel cells

• Anodes for direct dry methane oxidation in solid oxide fuel cells.
• Cu- and Ce-nitrate infiltration to the anode improves the carbon tolerance.
• The infiltration parameters are optimized systematically.
• 3 mL of 1 M Cu- and 2 mL of 1 M Ce-nitrate infiltration shows the best resistance.

In addition to pure hydrogen, solid oxide fuel cells (SOFCs) can utilize hydrocarbons as a fuel. However, conventional Ni-based anodes exhibit an excellent catalytic activity towards the hydrocarbon cracking reaction and thus the carbon deposition occurs in the anode. The deposited carbons quickly deactivate the anode irreversibly by covering the active surface of the anode catalyst. As a result, a significant degradation in the cell performance can be seen. In this study, the anode structure is modified by the addition of copper (Cu) and ceria (CeO2) to increase the coking resistance of the cell under direct methane fuel. In this respect, the anodes are infiltrated by different amounts of Cu and CeO2 nitrates via the wet impregnation technique to investigate the effects of Cu and CeO2 loadings on the carbon tolerance of the cell. The effects of the anode porosity and composition are also considered in the study. The carbon resistance thus the service life of the cell with Cu/CeO2/Ni/YSZ anodes is found to be significantly higher than that of conventional Ni-based anodes under direct dry methane fuel.