Halide-guided active site exposure in bismuth electrocatalysts for selective CO2 conversion into formic acid

Shuang Yang, Hongyu An, Sven Arnouts, Hui Wang, Xiang Yu, Jim de Ruiter, Sara Bals, Thomas Altantzis, Bert M. Weckhuysen*, Ward van der Stam*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

Abstract

It remains a challenge to identify the active sites of bismuth catalysts in the electrochemical CO2 reduction reaction. Here we show through in situ characterization that the activation of bismuth oxyhalide electrocatalysts to metallic bismuth is guided by the halides. In situ X-ray diffraction results show that bromide promotes the selective exposure of planar bismuth surfaces, whereas chloride and iodide result in more disordered active sites. Furthermore, we find that bromide-activated bismuth catalysts outperform the chloride and iodide counterparts, achieving high current density (>100 mA cm–2) and formic acid selectivity (>90%), suggesting that planar bismuth surfaces are more active for the electrochemical CO2 reduction reaction. In addition, in situ X-ray absorption spectroscopy measurements reveal that the reconstruction proceeds rapidly in chloride-activated bismuth and gradually when bromide is present, facilitating the formation of ordered planar surfaces. These findings show the pivotal role of halogens on selective facet exposure in activated bismuth-based electrocatalysts during the electrochemical CO2 reduction reaction. [Figure not available: see fulltext.]

Original languageEnglish
Article number6
Pages (from-to)796–806
Number of pages11
JournalNature Catalysis
Volume6
Issue number9
Early online dateAug 2023
DOIs
Publication statusPublished - Sept 2023

Keywords

  • Carbon-dioxide
  • Challenges
  • Electrochemical co2
  • Electrodes
  • Electroreduction
  • Formate
  • Light
  • Mechanism
  • Nanosheets
  • Reduction

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