Surface tuned La0.9Ca0.1Fe0.9Nb0.1O3-δ based anode for direct methane solid oxide fuel cells by infiltration method

It has been found in our previous study that La0.9Ca0.1Fe0.9Nb0.1O3-δ-Sm0.2Ce0.8O1.9 (LCFNb-SDC) anode shows high catalytic activity and stability for solid oxide fuel cells (SOFCs) under H2 and CO atmospheres. In this study, LCFNb-SDC is further tuned into a promising anode for direct methane SOFCs through surface modification with Ni. The LCFNb, SDC and Ni materials are found to be thermal-mechanically and chemically compatible with each other up to 850 °C. Although LCFNb-SDC anode shows poor catalytic activity for methane oxidation, further modification of such anode with a small amount of Ni particles significantly improves the cell performance in CH4. The maximal power densities of 1031 and 729 mW cm−2 in H2 and CH4 have been achieved for the electrolyte supported SOFC with LCFNb-SDC-Ni|SSZ (Sc0.2Zr0.8O2−δ)|LSM (La0.8Sr0.2MnO3) configuration at 850 °C, respectively. Besides, the same cells also exhibit good stabilities in both H2 (500 h) and CH4 (100 h) with no obvious performance degradation and carbon deposition. Surface tuned LCFNb anode by impregnating SDC and a small amount of Ni is thus highly promising as an anode for direct methane SOFCs to deliver favorable performance with reasonable stability.