{"title":"电渗透流与碱水电解的极限电流","authors":"J.W. Haverkort, H. Rajaei","doi":"10.1016/j.powera.2020.100034","DOIUrl":null,"url":null,"abstract":"<div><p>Under alkaline conditions, hydroxide ions can deplete at the anode of a water electrolyser for hydrogen production, resulting in a limiting current density. We found experimentally that in a micro-porous separator, an electro-osmotic flow from anode to cathode lowers this limiting current density. Using the Nernst-Planck equation, a useful expression for the potential drop in the presence of diffusion, migration, and advection is derived. A quasi-stationary, one-dimensional model is used to successfully describe the transient dynamics. Electro-osmotic flow-driven cross-over of dissolved oxygen is argued to impact the hydrogen purity.</p></div>","PeriodicalId":34318,"journal":{"name":"Journal of Power Sources Advances","volume":null,"pages":null},"PeriodicalIF":5.4000,"publicationDate":"2020-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.powera.2020.100034","citationCount":"14","resultStr":"{\"title\":\"Electro-osmotic flow and the limiting current in alkaline water electrolysis\",\"authors\":\"J.W. Haverkort, H. Rajaei\",\"doi\":\"10.1016/j.powera.2020.100034\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>Under alkaline conditions, hydroxide ions can deplete at the anode of a water electrolyser for hydrogen production, resulting in a limiting current density. We found experimentally that in a micro-porous separator, an electro-osmotic flow from anode to cathode lowers this limiting current density. Using the Nernst-Planck equation, a useful expression for the potential drop in the presence of diffusion, migration, and advection is derived. A quasi-stationary, one-dimensional model is used to successfully describe the transient dynamics. Electro-osmotic flow-driven cross-over of dissolved oxygen is argued to impact the hydrogen purity.</p></div>\",\"PeriodicalId\":34318,\"journal\":{\"name\":\"Journal of Power Sources Advances\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":5.4000,\"publicationDate\":\"2020-12-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://sci-hub-pdf.com/10.1016/j.powera.2020.100034\",\"citationCount\":\"14\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Journal of Power Sources Advances\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S2666248520300342\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"CHEMISTRY, PHYSICAL\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Power Sources Advances","FirstCategoryId":"1085","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S2666248520300342","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"CHEMISTRY, PHYSICAL","Score":null,"Total":0}
Electro-osmotic flow and the limiting current in alkaline water electrolysis
Under alkaline conditions, hydroxide ions can deplete at the anode of a water electrolyser for hydrogen production, resulting in a limiting current density. We found experimentally that in a micro-porous separator, an electro-osmotic flow from anode to cathode lowers this limiting current density. Using the Nernst-Planck equation, a useful expression for the potential drop in the presence of diffusion, migration, and advection is derived. A quasi-stationary, one-dimensional model is used to successfully describe the transient dynamics. Electro-osmotic flow-driven cross-over of dissolved oxygen is argued to impact the hydrogen purity.