Mewafy, B., Paloukis, F., Papazisi, K. M., Balomenou, S. P., Luo, W., Teschner, D., Joubert, O., La Salle, A. L. G., Niakolas, D. K. & Zafeiratos, S. (2019) Influence of Surface State on the Electrochemical Performance of Nickel-Based Cermet Electrodes during Steam Electrolysis. ACS Appl. Energ. Mater. 2 7045–7055.
Added by: Richard Baschera (2020-01-28 14:02:30) Last edited by: Richard Baschera (2020-01-28 14:03:33)
|Type de référence: Article
Numéro d'identification (ISBN etc.): 2574-0962
Clé BibTeX: Mewafy2019
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|Catégories: INTERNATIONAL, ST2E
Mots-clés: Anode, au-doped ni/gdc, ceria, cermet electrodes, deactivation, Degradation, doped ceria, hydrogen production, near ambient pressure XPS, oxide fuel-cell, reduction, solid oxide electrochemical cells, spectroscopy, stabilized zirconia cathode, steam electrolysis, water electrolysis, x-ray photoelectron
Créateurs: Balomenou, Joubert, La Salle, Luo, Mewafy, Niakolas, Paloukis, Papazisi, Teschner, Zafeiratos
Collection: ACS Appl. Energ. Mater.
Consultations : 7/271
Indice de consultation : 4%
Indice de popularité : 1%
Due to their fuel flexibility and high efficiency, solid oxide cells are a promising technology for sustainable energy production and storage. Nickel in combination with yttria-stabilized zirconia (YSZ) or gadolinium-doped ceria (GDC), forming Ni-YSZ or Ni-GDC cermets respectively, are the most widely adopted electrodes in solid oxide fuel cell fabrication. Currently, there is an increasing interest in cermet electrodes for hydrogen generation through high temperature steam electrolysis using solid oxide electrolysis cells (SOECs). However, durability remains a major issue for reliable operation of SOEC systems. A variety of processes accountable for permanent performance degradation of SOECs has been identified based on post-mortem cell analysis. Besides, transient/reversible degradation processes are typically examined by indirect methods, like impedance spectroscopy. The reason is that the application of material characterization techniques during SOEC operational conditions is challenging. In this work we provide a direct correlation between Ni-YSZ and Ni-GDC electrode surface oxidation states and their performance during steam electrolysis using operando experimental evidence provided by near ambient pressure X-ray photoelectron and near edge X-ray absorption fine structure spectroscopy. We show that nickel surface oxidation may induce significant performance degradation in Ni-YSZ cathodes while, on the contrary, having minor effects in Ni-GDC. Remarkably, we found that in the case of Ni-GDC electrodes, small modification of the GDC oxidation state can have an important impact on the electrolysis performance. The results highlight the crucial role of the cathode electrode surface oxidation state on the SOEC functionality and have potential implications for the design and operation strategies of more efficient and durable SOEC devices.