RuOx modified PrBaFe1.8Hf0.2O5+δ surface for boosting the performance of symmetrical solid oxide fuel cells

Abstract

The development of symmetrical solid oxide fuel cells (SSOFCs) faces a significant challenge in designing electrode materials that exhibit both high activity and stability. In this work, a novel layered perovskite oxide symmetric electrode material PrBaFe1.8Hf0.2O5+δ (PBFH) for SSOFCs is proposed and synthesized. Doping Hf at the B-site of PrBaFe2O5+δ (PBF) improves the stability in reducing atmosphere and increases the concentration of oxygen vacancies. Furthermore, a small amount of RuOx is deposited by atomic layer deposition (ALD) onto PrBaFe1.8Hf0.2O5+δ scaffold as symmetric electrodes. The surface modification of ALD-RuOx significantly boosts the catalytic activity for both fuel oxidation and oxygen reduction, simultaneously. Compared to PBF electrodes, the interfacial polarization resistances of RuOx-PBFH decrease to 0.77 Ω cm2 under H2/Ar and 0.021 Ω cm2 under air atmosphere at 800 °C, respectively. At 800 °C, SSOFCs equipped with RuOx-PBFH symmetric electrodes exhibit a high peak power density of 0.85 W cm−2 and 0.41 W cm−2 using humidified hydrogen and propane as fuels, respectively. Moreover, the RuOx-PBFH electrode demonstrates long-lasting performance, displaying high resistance against coking. These findings reveal a facile ALD approach for tailoring symmetric perovskite electrodes, offering robust and efficient electrocatalysis with efficient noble metal utilization.