In Situ Exsolved Nanoparticles on La0.5Sr1.5Fe1.5Mo0.5O6-δ Anode Enhance the Hydrogen Oxidation Reaction in SOFCs

uIn situ exsolution of nanoparticles is widely considered as an efficient and cost-effective method for increasing the number of active sites and consequently the catalytic activity on ceramic anodes in solid oxide fuel cells (SOFCs). In this study, by doping on the A-site of Sr2Fe1.5Mo0.5O6-delta (SF1.5 M), evenly distributed Fe nanoparticles (similar to 100 nm) were exsolved on the La0.5Sr1.5Fe1.5Mo0.5O6- delta (LSFM) surface under a typical anode operating environment (humidified H-2, 800 degrees C). In addition, the exsolution-dissolution reversibility of the exsolved Fe nanoparticles was observed during a redox cycle. Electrical conductivity relaxation (ECR) analysis demonstrated that the surface reaction kinetics on the LSFM anode is enhanced by in situ exsolution. Based on electrochemical impedance spectroscopy (EIS) and distribution of relaxation time (DRT) analysis, the perovskite structure was not damaged by the exsolution or the surface phase transition. During exsolution, the ionic conductivity increased. The higher surface catalytic activity and faster oxygen transportation led to enhanced electrochemical performance. (C) 2020 The Electrochemical Society ("ECS"). Published on behalf of ECS by IOP Publishing Limited.