气候变化领域集成服务门户(CCPortal): Towards membrane-electrode assembly systems for CO2 reduction: A modeling study

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DOI	10.1039/c9ee00909d
	Towards membrane-electrode assembly systems for CO2 reduction: A modeling study
	Weng L.-C.; Bell A.T.; Weber A.Z.
发表日期	2019
ISSN	1754-5692
起始页码	1950
结束页码	1968
卷号	12 期号:6
英文摘要	Membrane-electrode assemblies (MEAs) are an attractive cell design for the electrochemical reduction of CO2 because they exhibit low ohmic loss and high energy efficiency. We describe here the development and application of a multiphysics model to investigate the fundamental limitations of two MEA designs: one with gaseous feeds at both the anode and cathode (full-MEA), and the other with an aqueous anode feed (KHCO3 or KOH exchange solution) and a gaseous cathode feed (exchange-MEA). The total current density for the three cases follows the order: KOH-MEA > KHCO3-MEA > full-MEA. This trend is established by examining the distribution of the applied voltage. We show that the main charge-carrying species are carbonate anions for an MEA that uses an anion-exchange membrane (AEM). The amount of CO2 consumed but not converted to CO decreases with increasing current densities above 100 mA cm-2 for a full-MEA, but converges to 50% for exchange-MEAs. The full-MEA becomes limited by ohmic resistance as the membrane dehydrates with increasing cell temperature, and eventually becomes limited due to water mass transport. The exchange-MEAs can maintain membrane hydration and the local ion concentration at the anode, but are limited by salt precipitation at the cathode, as well as a higher tendency to flood. Finally, we explore the effects of temperature and discuss the possibility of increasing water supply to the full-MEA to improve its performance at elevated temperatures. The MEA model and the understanding of MEA performance for the electrochemical reduction of CO2 presented in this study should help guide the design of next-generation CO2 reduction cells. © 2019 The Royal Society of Chemistry.
语种	英语
scopus关键词	Anodes; Carbon dioxide; Cathodes; Electrochemical electrodes; Electrolytic reduction; Energy efficiency; Ion exchange; Ion exchange membranes; Membranes; Negative ions; Ohmic contacts; Potassium hydroxide; Temperature; Water supply; Anion exchange membranes (AEM); Development and applications; Effects of temperature; Electrochemical reductions; Fundamental limitations; High energy efficiency; Membrane electrode assemblies; Multi-physics modeling; More electric aircraft; carbon dioxide; electrochemical method; electrode; energy efficiency; membrane; modeling; performance assessment; precipitation (chemistry); reduction; temperature effect
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/162838
作者单位	Joint Center for Artificial Photosynthesis, LBNL, Berkeley, CA 94720, United States; Department of Chemical and Biomolecular Engineering, UC Berkeley, Berkeley, CA 94720, United States
推荐引用方式 GB/T 7714	Weng L.-C.,Bell A.T.,Weber A.Z.. Towards membrane-electrode assembly systems for CO2 reduction: A modeling study[J],2019,12(6).
APA	Weng L.-C.,Bell A.T.,&Weber A.Z..(2019).Towards membrane-electrode assembly systems for CO2 reduction: A modeling study.Energy and Environmental Science,12(6).
MLA	Weng L.-C.,et al."Towards membrane-electrode assembly systems for CO2 reduction: A modeling study".Energy and Environmental Science 12.6(2019).