In Situ Raman Study of Potential-Dependent Surface Adsorbed Carbonate, CO, OH, and C Species on Cu Electrodes During Electrochemical Reduction of CO2

Mozhgan Moradzaman, Guido Mul*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

69 Citations (Scopus)
135 Downloads (Pure)

Abstract

Using in situ surface-enhanced Raman spectroscopy (SERS), and 13C/12C and D2O/H2O isotopic labeling for assignment, we show potential dependent transients in surface composition of Cu-catalyzed electrochemical reduction of CO2 in carbonate solution. First, reduction of Cu(I)oxide is accompanied by adsorption of predominantly monodentate carbonate at ∼1067 cm−1 starting in the potential range from [+0.2 V→−0.2 V]. Contrary to recently advocated hypotheses, and based on the significant presence at anodic potential, a band in this potential range at ∼1540 cm−1 can be assigned to bidentate carbonate. As expected, appearance of surface CO was observed in the range of [−0.4 V→−1.0 V], clearly identified by the Cu−CO vibration at 360 cm−1. Most importantly, at the more negative end of this potential range, we identified the formation of surface OH, and for the first time a surface Cu−C species, showing Raman bands at ∼525 cm−1 (Cu−OH) and ∼500 cm−1 (Cu−C), respectively. In the potential range of [−1.0 V→−1.4 V], surface CO disappears, while the Cu−OH and Cu−C species are persistent. Interestingly positive polarization at >0.1 V removes these species and restores the surface to Cu(I)oxide, rendering the surface processes completely reversible. Implications of this study for mechanistic understanding of electrode deactivation and practical operation are discussed.

Original languageEnglish
Pages (from-to)1478-1485
Number of pages8
JournalChemElectroChem
Volume8
Issue number8
DOIs
Publication statusPublished - 12 Apr 2021

Keywords

  • carbon monoxide
  • carbonate
  • copper(I)oxide
  • electrochemical CO reduction
  • hydroxide
  • in-situ Raman Spectroscopy
  • isotopic labeling
  • polycrystalline copper
  • UT-Hybrid-D

Fingerprint

Dive into the research topics of 'In Situ Raman Study of Potential-Dependent Surface Adsorbed Carbonate, CO, OH, and C Species on Cu Electrodes During Electrochemical Reduction of CO2'. Together they form a unique fingerprint.

Cite this