Xiulin Yang, Defei Liu, S. Zhong, Xiaofeng Zhou, Kuo‐Wei Huang, Lain‐Jong Li, Z. Lai
{"title":"Selective Conversion of Carbon Dioxide to Formate with High Current Densities","authors":"Xiulin Yang, Defei Liu, S. Zhong, Xiaofeng Zhou, Kuo‐Wei Huang, Lain‐Jong Li, Z. Lai","doi":"10.1142/S2251237321500015","DOIUrl":null,"url":null,"abstract":"Selective conversion of CO2 to formate with high current densities is highly desirable but still challenging. Copper hollow fibers with interconnected pore structures were fabricated via a facile method and used as a stand-alone cathode for highly efficient electrochemical reduction of CO2 to formate. Our studies revealed that delivering the reactant CO2 gas to the inner space of the hollow fiber could build up a higher CO2 partial pressure in the pores and presumably reduce the concentration of H[Formula: see text] from the electrolyte to effectively suppress the major competing reaction, hydrogen evolution reaction (HER), from 46.9% faradaic efficiency (FE) to 15.0%. A high selectivity for CO2 reduction to formate with a maximum FE of 77.1% was achieved with a high current density of 34.7[Formula: see text]mA cm[Formula: see text], which is one of the highest FEs on Cu-based materials. Mechanistic studies suggest that the abundant active sites along with the unique crystal facets induced by the high pressure of CO2 at the pore surface in the “gas in” mode are attributed to the superior electroactivity and selectivity for the CO2 reduction to formate. The Cu hollow fiber electrodes exhibit an outstanding long-term stability at high current density, showing great potential for large-scale practical applications.","PeriodicalId":16406,"journal":{"name":"Journal of Molecular and Engineering Materials","volume":null,"pages":null},"PeriodicalIF":2.4000,"publicationDate":"2021-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Molecular and Engineering Materials","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1142/S2251237321500015","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"MATERIALS SCIENCE, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
Abstract
Selective conversion of CO2 to formate with high current densities is highly desirable but still challenging. Copper hollow fibers with interconnected pore structures were fabricated via a facile method and used as a stand-alone cathode for highly efficient electrochemical reduction of CO2 to formate. Our studies revealed that delivering the reactant CO2 gas to the inner space of the hollow fiber could build up a higher CO2 partial pressure in the pores and presumably reduce the concentration of H[Formula: see text] from the electrolyte to effectively suppress the major competing reaction, hydrogen evolution reaction (HER), from 46.9% faradaic efficiency (FE) to 15.0%. A high selectivity for CO2 reduction to formate with a maximum FE of 77.1% was achieved with a high current density of 34.7[Formula: see text]mA cm[Formula: see text], which is one of the highest FEs on Cu-based materials. Mechanistic studies suggest that the abundant active sites along with the unique crystal facets induced by the high pressure of CO2 at the pore surface in the “gas in” mode are attributed to the superior electroactivity and selectivity for the CO2 reduction to formate. The Cu hollow fiber electrodes exhibit an outstanding long-term stability at high current density, showing great potential for large-scale practical applications.
高电流密度的CO2选择性转化为甲酸是非常理想的,但仍然具有挑战性。采用简单的方法制备了具有互连孔结构的铜中空纤维,并将其用作独立阴极,用于高效电化学还原CO2生成甲酸。我们的研究表明,将反应物CO2气体输送到中空纤维的内部空间可以在孔隙中建立更高的CO2分压,并可能降低电解质中H的浓度,从而有效地抑制主要的竞争反应——析氢反应(HER),法拉第效率(FE)从46.9%降至15.0%。在34.7 mA cm的高电流密度下,CO2还原生成甲酸的选择性最高达到77.1%,是cu基材料中FEs最高的材料之一。机理研究表明,在“气进”模式下,由于CO2高压在孔隙表面产生了丰富的活性位点和独特的晶体面,这是由于CO2还原生成甲酸的优越电活性和选择性所致。铜空心纤维电极在高电流密度下具有优异的长期稳定性,具有大规模实际应用的潜力。