Spectroscopic Observation of Reversible Surface Reconstruction of Copper Electrodes under CO₂ Reduction

Abstract

The ability of copper to catalyze the electrochemical reduction of CO 2 has been shown to greatly depend on its nanoscale surface morphology. While previous studies found evidence of irreversible changes of copper nanoparticle and thin film electrodes following electrolysis, we present here the first observation of the reversible reconstruction of electrocatalytic copper surfaces induced by the adsorbed CO intermediate. Using attenuated total internal reflection infrared and surface-enhanced Raman spectroscopies, the reversible formation of nanoscale metal clusters on the electrode is revealed by the appearance of a new CO absorption band characteristic of CO bound to undercoordinated copper atoms and by the strong enhancement of the surface-enhanced Raman effect. Our study shows that the morphology of the catalytic copper surface is not static but dynamically adapts with changing reaction conditions.

On the Oxidation State of Cu2O upon Electrochemical CO2 Reduction: An XPS Study

“…Figure S5). Interestingly, this surface morphology change at CO 2 ‐reduction potentials is qualitatively consistent with previous observations for Cu‐catalysts, and has recently been suggested to be triggered by surface‐adsorbed CO produced as a CO 2 ‐reduction intermediate . Moreover, the specific appearance of cracks in the TF is likely related to the reduction of the initial Cu 2 O to Cu 0 in the course of CO 2 ‐electroreduction (cf.…”

Controlled Selectivity of CO2 Reduction on Copper by Pulsing the Electrochemical Potential

“…[24] Interestingly, the restructuring appears to occur at timescales comparable to the pulse duration. [24] Interestingly, the restructuring appears to occur at timescales comparable to the pulse duration.…”

Selective CO2 Electroreduction to Ethylene and Multicarbon Alcohols via Electrolyte‐Driven Nanostructuring

“…Previous experimental and theoretical studies demonstrated that Cu(100) is the most favorable crystal orientation for the C−C coupling process . However, the surface of Cu electrodes under electrochemical environments often undergoes reconstructions induced by applied potentials, the intermediates formed during CO 2 RR, as well as specifically adsorbed anions . On the other hand, some anions either present in the electrolyte or adsorbed on the electrode surface, have been shown to play a vital role in the dynamic evolution of the catalyst structure under reaction conditions as well as the activity and selectivity of CO 2 RR.…”