NdBaFe<sub>2–<i>x</i></sub>Co<sub><i>x</i></sub>O<sub>5+δ</sub> Double Perovskites with Exsolved Co–Fe Alloy Nanoparticles as Highly Efficient and Stable Anodes for Direct Hydrocarbon Solid Oxide Fuel Cells
Jiadong Jiang, Ying Zhang, Xin Yang, Yu Shen, Tianmin He
Abstract
Exsolution of transition metals in perovskites is a potential way to improve the catalytic activity of fuel cell anode materials. In this work, the double-perovskite anodes PR-NdBaFe2–xCoxO5+δ (x = 0.1, 0.2; PR-NBFC10, PR-NBFC20) with the exsolved Co0.72Fe0.28 metal alloy nanoparticles were obtained by heat treatment in 5% H2/Ar post-reduction at 850 °C. The exsolved Co–Fe alloy nanoparticle catalyst uniformly distributed on the surface of the cobalt-doped PR-NBFC10 and PR-NBFC20 ceramic anodes facilitates the catalytic activity compared with the undoped PR-NdBaFe2–xCoxO5+δ (x = 0; PR-NBFC0) anode. The maximum power density of single cells with PR-NBFC0, PR-NBFC10, and PR-NBFC20 anodes supported by a 200 μm thick La0.9Sr0.1Ga0.8Mg0.2O3−δ electrolyte at 850 °C in wet H2 reached 842, 1110, and 1247 mW cm–2, respectively. In addition, PR-NBFC0, PR-NBFC10, and PR-NBFC20 exhibit relatively stable output power in a wet CH4 fuel within 100 h of operation. Since the exsolved Co–Fe alloy nanoparticles have an embedded structure, they exhibit impressive anticoking properties, which greatly expand their application. The PR-NBFC double perovskite containing Co–Fe alloy nanoparticles offers possibilities for finding promising high-catalytic-activity and high-stability anodes for solid oxide fuel cells.