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

Abstract

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 729mWcm−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 (500h) and CH4 (100h) 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.