In situ exsolved Fe-Ni nanoparticles on Pr0.8La0.2FexNi1-xO3-δ perovskite as high-performance anode for solid oxide fuel cells

Nanoarchitectures in catalyst design have garnered significant attention due to their ability to enhance performance, durability, and resistance against undesirable side reactions. In this work, an in situ exsolution method was employed to decorate the electrode surface with nanoparticles, aiming to enhance the electrochemical performance and long-term stability of the solid oxide fuel cells (SOFCs) anode. Initially, the Pr 0.8 La 0.2 Fe x Ni 1- x O 3- δ (PLFN, x  = 0.4, 0.5) powders were synthesized and subsequently processed by in situ hydrogen reduction. Following the exsolution, characterization by Rietveld refinement of X-ray diffraction (XRD) patterns and high-resolution transmission electron microscopy (HRTEM) confirmed the formation of Fe-Ni alloy and LaFeO 3 particles. Correlation with electrochemical measurements revealed that the enhanced anode performance is primarily due to the surface Fe-Ni alloy nanoparticles. Furthermore, X-ray photoelectron spectroscopy (XPS) analysis verified the metallic state of the exsolved Fe and Ni species after reduction. Finally, the PLFN material was applied as an anode in an electrolyte-supported single cell, and Pr 0.8 La 0.2 Fe 0.4 Ni 0.6 O 3- δ (PLF 0.4 N 0.6 ) demonstrated superior output performance under different reduction temperatures. Meanwhile, the peak power densities with PLF 0.4 N 0.6 anode after in situ exsolution reached 1.04, 0.64, and 0.56 W cm −2 at 850 °C when using H 2 , NH 3 , and CH 4 as fuels, respectively, exhibiting remarkable fuel flexibility. Moreover, the single cell with PLF 0.4 N 0.6 as the anode exhibited excellent operational stability, showing a performance degradation rate of only 0.01% per hour over a 100-hour test. These results offer valuable insights into the rational design of next-generation SOFCs anodes possessing exceptional activity and durability.