气候变化领域集成服务门户(CCPortal): Quantification of water transport in a CO2electrolyzer

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DOI	10.1039/d0ee02219e
	Quantification of water transport in a CO2electrolyzer
	Wheeler D.G.; Mowbray B.A.W.; Reyes A.; Habibzadeh F.; He J.; Berlinguette C.P.
发表日期	2020
ISSN	1754-5692
起始页码	5126
结束页码	5134
卷号	13 期号:12
英文摘要	A sufficient supply of water at the catalyst layer is needed to mediate the CO2 reduction reaction (CO2RR), yet too much water favours the competing hydrogen evolution reaction (HER) and lowers the efficiency of CO2 electrolysis. It is therefore important to quantify water at the cathode, but CO2 electrolyzers are typically enclosed systems where only the inputs and outputs can be readily measured. We report herein an analytical CO2RR electrolyzer with sensors in the cathode chamber to directly measure the relative humidity (RH) and temperature during electrolysis. These measurements enable the flow of water to be tracked inside the flow cell, and provide the boundary conditions necessary for a 3D model of mass transport and fluid flow in the cathode chamber. We developed a 3D model which showed that the molar fraction of water at the cathodic GDE/membrane interface, xH2O,mem, is constant under a range of applied current densities (25-200 mA cm-2) and CO2 flow rates (25-200 sccm), and does not change as a function of humidification of the CO2 feed. The value of xH2O,mem is held at parity because more water is drawn across the membrane (from the liquid-fed anode) when insufficient water is supplied to the cathode from the CO2 feed. This result points to a higher flux of water across the membrane when using drier CO2 feedstocks at higher flow rates and higher current densities. Consequently, undesirable anolyte crossover (which causes salt precipitation at the cathode) can be suppressed by maintaining a humidified CO2 feed. This 3D model can be used for a range of operating conditions, materials, and flow fields to help with CO2RR electrolyzer design and optimization. This journal is © The Royal Society of Chemistry.
语种	英语
scopus关键词	3D modeling; Carbon dioxide; Cathodes; Electrolysis; Electrolytic cells; Flow of fluids; Precipitation (chemical); Transport properties; Catalyst layers; Cathode chambers; Design and optimization; Electrolyzers; Molar fractions; Operating condition; Salt precipitation; Water transport; Phase interfaces; carbon dioxide; electrokinesis; electrolyte; instrumentation; quantitative analysis
来源期刊	Energy and Environmental Science
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/162840
作者单位	Department of Chemical and Biological Engineering, University of British Columbia, 2360 East Mall, Vancouver, BC V6T 1Z3, Canada; Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, BC V6T 1Z1, Canada; Stewart Blusson Quantum Matter Institute, University of British Columbia, 2355 East Mall, Vancouver, BC V6T 1Z4, Canada; Canadian Institute for Advanced Research (CIFAR), 661 University Avenue, Toronto, ON M5G 1M1, Canada
推荐引用方式 GB/T 7714	Wheeler D.G.,Mowbray B.A.W.,Reyes A.,et al. Quantification of water transport in a CO2electrolyzer[J],2020,13(12).
APA	Wheeler D.G.,Mowbray B.A.W.,Reyes A.,Habibzadeh F.,He J.,&Berlinguette C.P..(2020).Quantification of water transport in a CO2electrolyzer.Energy and Environmental Science,13(12).
MLA	Wheeler D.G.,et al."Quantification of water transport in a CO2electrolyzer".Energy and Environmental Science 13.12(2020).