Surface reconstruction of pure-Cu single-crystal electrodes under CO-reduction potentials in alkaline solutions: A study by seriatim ECSTM-DEMS

Abstract

Quasi-operando electrochemical scanning tunneling microscopy (ECSTM) recentlyshowed that a polycrystalline Cu electrode kept in 0.1 M KOH at -0.9 V (SHE), a potential very close to that for electrochemical CO reduction, underwent a two-step surface reconstruction, initially to Cu(111), or Cu(pc)-[Cu (111)

Polycrystalline and Single‐Crystal Cu Electrodes: Influence of Experimental Conditions on the Electrochemical Properties in Alkaline Media

“…The atomically resolved STM image (top left corner of the large scale STM image) shows the quadratic arrangement of the surface Cu atoms for the (1 0 0) surface; these images provide no indications of contamination at an atomic scale. The quality of the surface structure of the Cu(1 0 0)‐UHV electrode, in terms of terrace size and step density, compares favourably with epitaxially grown Cu( hkl ) electrodes and Cu(1 0 0) electrodes pre‐treated under laboratory conditions and investigated with in situ STM ,,…”

“…However, the CV of the Cu(1 00 )‐UHV electrode does not show any distinct features in the potential region from 0.30 V to 0.45 V, which are normally observed for electrodes prepared under laboratory conditions (Figure ). Our STM results show only very few steps on large scale images compared to in situ STM images recorded on Cu(1 0 0) electrodes prepared under laboratory conditions ,,. We attribute the additional peaks observed in the CVs in the literature to an increased number of different facets/steps on the surface.…”

Selective conversion of CO into ethanol on Cu(511) surface reconstructed from Cu(pc): Operando studies by electrochemical scanning tunneling microscopy, mass spectrometry, quartz crystal nanobalance, and infrared spectroscopy

“…The only product detected at -1.06 V was ethanol (Figure 3), a potential that is 150 mV more positive than the onset of hydrocarbon production on Cu in basic medium. Neither the reconstructed Cu(pc)-[Cu(100)] surface nor the multiply cycled Cu(100) bulk electrode yielded ethanol and other CO-reduction products at the narrow potential window of interest [20]. The impact of this result rests on the identification of a welldefined operando surface structure of Cu responsible for the production of a singular alcohol.…”

Atomistic Mechanisms Underlying Selectivities in C1 and C2 Products from Electrochemical Reduction of CO on Cu(111)

“…8,9 Thus, CORR determines the overpotentials and selectivities for additionally reduced products from CO 2 RR, so we focus here on CORR. Cu(111) serves as a model electrocatalyst that delivers the essential chemistry of CORR, 10 and it has been confirmed to be stable under electrochemical working conditions, 11 so we focus here on CORR on Cu(111).…”