In situ growth of LaSr(Fe,Mo)O4 ceramic anodes with exsolved Fe–Ni nanoparticles for SOFCs: Electrochemical performance and stability in H2, CO, and syngas

Abstract

Fe–Ni nanoparticle–decorated LaSr(Fe,Mo)O4 Ruddlesden–Popper (R–P) perovskite anodes, named R–LSFMNx, were prepared in situ by reducing perovskites La0.5Sr0.5Fe0.9Mo0.1–xNixO3–δ (LSFMNx; x = 0.03–0.07) under SOFC anode operating conditions. Electrolyte–supported single cells with a configuration of R–LSFMNx|La0.9Sr0.1Ga0.8Mg0.2O3–δ (LSGM)|Ba0.5Sr0.5Co0.9Nb0.1O3–δ were used to evaluate the electrochemical performances and redox/long–term stability of the R–LSFMNx anodes fuelled by H2, CO, and simulated syngases (x% H2/CO; x = 50–10). EIS analyses indicated that the increased Ni level in the exsolved Fe–Ni nanocatalysts significantly promotes fuel diffusion/adsorption/dissociation, which plays a rate–limiting role in the anode fuel oxidation. Furthermore, the incremental Ni in Fe–Ni alloy also enhances the anode redox/long–term stability and carbon resistance/tolerance, and the R–LSFMN0.07 anode, i.e., Ni level in Fe–Ni alloy attaining ∼14 mol.%, displays the optimal stability and carbon resistance/tolerance. Finally, the potential of the R–LSFMN0.07 anode for direct utilization of syngas was demonstrated by the characterization of the electrochemical performance and stability based on the R–LSFMN0.07 anode cell.