Seriatim ECSTM-ECPMIRS of the adsorption of carbon monoxide on Cu(100) in alkaline solution at CO2-reduction potentials

• Published in: Electrochemistry communications 2018-06, Vol.91 (C), p.1-4
• Main Authors: Baricuatro, Jack H., Kim, Youn-Geun, Korzeniewski, Carol L., Soriaga, Manuel P.
• Format: Article
• Language: English
• Subjects: Electrochemical reduction of CO2 in alkaline solution; Electrochemistry; Operando electrode-surface nanoscopy; Operando molecular vibrational spectroscopy; Potential-dependent CO adsorption on Cu; Seriatim ECSTM-ECPMIRS
• ISSN: 1388-2481; 1873-1902
• DOI: 10.1016/j.elecom.2018.04.016

It was recently demonstrated that the sequential or seriatim application of electrochemical scanning tunneling microscopy (ECSTM) and differential electrochemical mass spectrometry (DEMS) enables the correlation, under actual reaction conditions, of a specific structure on a Cu electrode surface with the generation of a particular CO-reduction product. As an extension of the operando hyphenated-technique approach, we paired ECSTM with electrochemical polarization-modulation IR reflection-absorption spectroscopy (ECPMIRS) to identify a delineating potential that affected the coverage, the molecular orientation, and the adlattice structure of CO adsorbed on Cu(100) in 0.1 M KOH under CO2-reduction conditions. The results may have significant ramifications on the theory-based reaction mechanism for the formation of C2 compounds, as well as insights into the mode of coordination between CO and zerovalent Cu. [Display omitted] •Operando STM and PMIRS were applied seriatim to study CO adsorption on Cu(100)•Coverage, structure, and orientation of CO adsorbed on Cu(100) were determined•In 0.1 M KOH, CO is chemisorbed on Cu(100) only at E ≤ -0.85 V (SHE)•CO molecules in Cu(100)-c(2×2)-CO adlattice are adsorbed vertically on atop sites•The limiting coverage θCO is 0.5, consistent with Cu2-CO coordination stoichiometry