Electrically conducting oxides have been proposed as alternatives to Ni-based cermet anodes for solid oxide fuel cells (SOFCs) to overcome issues such as coking and impurity poisoning, but their electrochemical performance is typically inferior to that of Ni-based cermets. Here we show that a new oxide composition, Sr_0.95(Ti_0.3Fe_0.63Ni_0.07)O_3−δ, yields anode polarization resistance competitive with Ni cermets, and substantially better than that of the corresponding Ni-free compound, SrTi_0.3Fe_0.7O_3−δ. Exposure to fuel results in exsolution and nucleation of Ni_0.5Fe_0.5 nanoparticles uniformly dispersed on the Ni-substituted perovskite surface, whereas no nanoparticles are observed on SrTi_0.3Fe_0.7O_3−δ. A general thermodynamic model is developed that quantitatively predicts exsolved nanoparticle composition. The reduction in anode polarization resistance by the nanoparticles, by as much as 4 times, is most pronounced at cell operating temperatures below 800°C and low H₂ partial pressures, suggesting that the nanoparticles improve performance by promoting H₂ adsorption.

已经提出了导电氧化物作为用于固体氧化物燃料电池（SOFC）的镍基金属陶瓷阳极的替代品，以克服诸如焦化和杂质中毒的问题，但是它们的电化学性能通常不如镍基金属陶瓷。在这里，我们显示了一种新的氧化物成分Sr _0.95（Ti _0.3 Fe _0.63 Ni _0.07）O3 _-δ，其阳极极化电阻可与Ni金属陶瓷竞争，并且明显优于相应的无镍化合物SrTi _0.3 Fe _0.7 O _3−δ。暴露于燃料中会导致Ni _0.5 Fe _0.5析出并成核纳米粒子均匀地分散在Ni取代的钙钛矿表面上，而在SrTi _0.3 Fe _0.7 O3 _-δ上未观察到纳米粒子。建立了通用的热力学模型，该模型定量预测了溶解的纳米颗粒的组成。在低于800°C的电池工作温度和低H ₂分压的情况下，纳米粒子将阳极极化电阻降低多达4倍，这最明显，这表明纳米粒子通过促进H ₂吸附来提高性能。