Evaluation of the CO2 Poisoning Effect on a Highly Active Cathode SrSc0.175Nb0.025Co0.8O3-δ in the Oxygen Reduction Reaction

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• 作者：Yuan Zhang ; Guangming Yang ; Gao Chen ; Ran Ran ; Wei Zhou ; Zongping Shao
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2016
• 出版时间：February 10, 2016
• 年：2016
• 卷：8
• 期：5
• 页码：3003-3011
• 全文大小：622K
• ISSN：1944-8252

文摘

A solid oxide fuel cell (SOFC) is a highly efficient device for converting chemical energy to electrical energy. In addition to the efforts to reduce the operating temperature of SOFCs to below 600 °C, research studies of the basic mechanism of CO₂ poisoning on cathode materials are envisioned to improve the operation of dual-chamber SOFCs using ambient air. In this work, we comparatively studied the CO₂ poisoning effect on two highly active perovskites SrSc_0.175Nb_0.025Co_0.8O_3-δ (SSNC) and Ba_0.5Sr_0.5Co_0.8Fe_0.2O_3-δ (BSCF), using complementary characterization techniques, e.g., powder X-ray diffraction (XRD), Fourier transform-infrared (FT-IR) spectroscopy, atomic force microscopy (AFM), scanning electron microscopy (SEM), CO₂-temperature-programmed desorption (CO₂-TPD), and electrochemical impedance spectroscopy (EIS). The SSNC cathode shows better tolerance to CO₂ as compared with BSCF, which is attributed to the absence of Ba, higher average metal–oxygen bond energy (ABE) of SSNC, and the higher acidity of Nb⁵⁺ cations, whereas the oxygen vacancy concentration plays a less important role.