文章基本信息

标题：Observation of Preferential Pathways for Oxygen Removal through Porous Transport Layers of Polymer Electrolyte Water Electrolyzers
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作者：Pongsarun Satjaritanun ; Maeve O'Brien ; Devashish Kulkarni 等
期刊名称：iScience
印刷版ISSN：2589-0042
出版年度：2020
卷号：23
期号：12
页码：1-43
DOI：10.1016/j.isci.2020.101783
语种：English
出版社：Elsevier
摘要：SummaryUnderstanding the relationships between porous transport layer (PTL) morphology and oxygen removal is essential to improve the polymer electrolyte water electrolyzer (PEWE) performance.OperandoX-ray computed tomography and machine learning were performed on a model electrolyzer at different water flow rates and current densities to determine how these operating conditions alter oxygen transport in the PTLs. We report a direct observation of oxygen taking preferential pathways through the PTL, regardless of the water flow rate or current density (1-4 A/cm2). Oxygen distribution in the PTL had a periodic behavior with period of 400μm. A computational fluid dynamics model was used to predict oxygen distribution in the PTL showing periodic oxygen front. Observed oxygen distribution is due to low in-plane PTL tortuosity and high porosity enabling merging of oxygen bubbles in the middle of the PTL and also due to aerophobicity of the layer.Graphical AbstractDisplay OmittedHighlights•O2pathways in the PTLs of a water electrolyzer were observed with operando X-ray CT•Periodicity of the O2transport pathway observed here with the period of 400 μm•O2is taking preferential pathways through PTLs at various water flow rates and currents•Merging of oxygen front in the middle of PTL is observed due to good in-plane transportChemistry; Chemical Engineering; Electrochemistry; Electrochemical Energy Conversion; Energy Materials