Synergistically Promoting Coking Resistance of a La_0.4Sr_0.4Ti_0.85Ni_0.15O_3−δ Anode by Ru-Doping-Induced Active Twin Defects and Highly Dispersed Ni Nanoparticles

Abstract

The development of anodes with highly efficient electrochemical catalysis and good durability is crucial for solid oxide fuel cells (SOFCs). This paper reports a superior Ru-doped La_0.4Sr_0.4Ti_0.85Ni_0.15O_3-δ (L0.4STN) anode material with excellent catalytic activity and good stability. The doping of Ru can inhibit the agglomeration of in situ-exsolved Ni nanoparticles on the surface and induce the formation of abundant multiple-twinned defects in the perovskite matrix, which significantly increase the concentration of oxygen vacancies. The reduced L0.4STRN (R-L0.4STRN) anode shows an area-specific resistance (ASR) of 0.067 Ω cm² at 800 °C, which is only about one-third of that of stochiometric R-L0.6STN (0.212 Ω cm²). A single cell with the R-L0.4STRN anode shows excellent stability (∼50 h at 650 °C) in both H₂ and CH₄. Furthermore, R-L0.4STRN exhibits outstanding resistance to carbon deposition, which can be attributed to the synergistic effect of highly dispersed Ni nanoparticles and active twinned defects induced by Ru doping.