Rapid porosity formation of silver under SOFC conditions in methane-oxygen mixed gas. (21st December 2016)

• Record Type: Journal Article
• Authors: Wang, Zhihong; Yan, Yingming; Liu, Mengting; Chen, Yifu; Han, Wenqiao; Bian, Haiwen; Qiao, Yu; Xiong, Yueping; Lv, Zhe
• Is Part Of: International journal of hydrogen energy. Volume 41:Number 47(2016)
• Page Start: 22344
• Page End: 22353
• Publication Date: 2016-12-21
• Subjects: Solid oxide fuel cells -- Silver -- CH4O2 mixed gas -- Porosity formation -- Structure stability; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2016.08.163
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: Solid silver (Ag) is widely used current collector for solid oxide fuel cells (SOFCs). Here, its structure stability is examined in methane-oxygen mixed gas at a furnace temperature range of 600–750 °C. Rapid porosity formation is observed for solid Ag samples, especially in the presence of Ni/yttria-stabilized zirconia (YSZ) anode materials. This is mainly attributed to simultaneous diffusion of hydrogen, carbon monoxide and oxygen into Ag bulk, followed by subsequent interaction resulting in the formation of water and carbon dioxide gas. The obtained results demonstrate that partial oxidation of methane and the formation of hydrogen and carbon monoxide play an important role in the rapid porosity formation of Ag under the above specified operating conditions. Furthermore, the porosity formation of Ag samples is closely related to methane-oxygen-ratio ( R mix ) and operating temperatures. Graphical abstract: Highlights: Rapid porosity formation is observed for solid Ag under SOFC conditions in CH4 O2 mixed gas. The reaction of H, CO and O in Ag bulk leads to the porosity of Ag. The catalysis of Ni-YSZ materials plays an important role in porosity of Ag. The porosity of Ag is closely related to R mix and operating temperature. Ag is not stable under SOFC conditions with hydrocarbon-air mixed gas.