{"title":"CO<sub>2</sub> Reduction to Formic Acid/Formate by Intermittent Electricity at Bismuth Gas Diffusion Electrodes.","authors":"Ida Dinges, Siegfried R Waldvogel, Markus Stöckl","doi":"10.1002/cssc.202501583","DOIUrl":null,"url":null,"abstract":"<p><p>To avoid the waste of renewable energy resources beyond demand and grid capacity, innovative gas diffusion electrodes (GDE) for operation at intermittent electricity are presented. They are based on Bi as affordable and nontoxic electrocatalyst, to facilitate decentralized and cost-efficient reduction of CO<sub>2</sub> to formic acid. To develop flexible GDE materials, their catalyst composition is optimized by studying systematically inexpensive Bi/Bi<sub>2</sub>O<sub>3</sub> mixtures. During initial evaluation at technically relevant current density (150 mA cm<sup>-2</sup>, 21 h), the best composition achieve high Faradaic efficiency (FE) (≈90%) and the loss of catalyst is minor. In three demonstrative examples of realistic current patterns based on intermittent electricity, the performance and resilience of the optimized GDE is consistently very good in terms of high FE (≈90%) and stable synthesis rates of formate. However, loss of catalyst is partially increased, especially when GDEs are depolarized between electrolysis phases. Nonetheless, the GDE materials already show robust performances despite swift adjustments of current density (60 s) without any optimization of operational parameters so far. Based on these results, flexible operation of these GDE can be optimized to minimize cathodic corrosion of catalyst at long-term operation, and thus, ultimately evaluate their implementation to valorize intermittent electricity.</p>","PeriodicalId":149,"journal":{"name":"ChemSusChem","volume":" ","pages":"e202501583"},"PeriodicalIF":6.6000,"publicationDate":"2025-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"ChemSusChem","FirstCategoryId":"92","ListUrlMain":"https://doi.org/10.1002/cssc.202501583","RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"CHEMISTRY, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
Abstract
To avoid the waste of renewable energy resources beyond demand and grid capacity, innovative gas diffusion electrodes (GDE) for operation at intermittent electricity are presented. They are based on Bi as affordable and nontoxic electrocatalyst, to facilitate decentralized and cost-efficient reduction of CO2 to formic acid. To develop flexible GDE materials, their catalyst composition is optimized by studying systematically inexpensive Bi/Bi2O3 mixtures. During initial evaluation at technically relevant current density (150 mA cm-2, 21 h), the best composition achieve high Faradaic efficiency (FE) (≈90%) and the loss of catalyst is minor. In three demonstrative examples of realistic current patterns based on intermittent electricity, the performance and resilience of the optimized GDE is consistently very good in terms of high FE (≈90%) and stable synthesis rates of formate. However, loss of catalyst is partially increased, especially when GDEs are depolarized between electrolysis phases. Nonetheless, the GDE materials already show robust performances despite swift adjustments of current density (60 s) without any optimization of operational parameters so far. Based on these results, flexible operation of these GDE can be optimized to minimize cathodic corrosion of catalyst at long-term operation, and thus, ultimately evaluate their implementation to valorize intermittent electricity.
为了避免可再生能源资源超出需求和电网容量的浪费,提出了一种用于间歇性电力运行的新型气体扩散电极(GDE)。它们以铋为基础,可负担得起且无毒的电催化剂,以促进分散和经济高效地将二氧化碳还原为甲酸。为了开发柔性GDE材料,系统地研究了廉价的Bi/Bi2O3混合物,优化了催化剂的组成。在技术相关电流密度(150 mA cm-2, 21 h)下的初步评价中,最佳的组成达到了较高的法拉第效率(FE)(≈90%),催化剂损失较小。在基于间歇电的现实电流模式的三个示范示例中,优化的GDE在高FE(≈90%)和甲酸合成速率稳定方面的性能和弹性始终非常好。然而,催化剂的损失部分增加,特别是当gde在电解相之间去极化时。尽管如此,在没有任何操作参数优化的情况下,尽管电流密度(60秒)的快速调整,GDE材料已经显示出强大的性能。基于这些结果,可以优化这些GDE的灵活运行,以最大限度地减少催化剂在长期运行时的阴极腐蚀,从而最终评估它们对间歇性电力的实现。
期刊介绍:
ChemSusChem
Impact Factor (2016): 7.226
Scope:
Interdisciplinary journal
Focuses on research at the interface of chemistry and sustainability
Features the best research on sustainability and energy
Areas Covered:
Chemistry
Materials Science
Chemical Engineering
Biotechnology