Insight into the Formation and Transfer Process of the First Intermediate of CO₂ Reduction over Ag‐Decorated Dendritic Cu

Abstract

It is still poorly understood how the first intermediates of CO 2 reduction are formed and converted to multi-carbon products over Cu-based electrodes. Herein,A g is used to decorated endritic Cu and ah igh Faradaic efficiency (FE) for C 2 H 4 (25 %) is obtained on aC uAg electrode, which is about five times higher than dendritic Cu. The intermediates including *CO 2 À ,O Hg roups,C u-CO, C-O rotation, and CH x speciesa re investigated by in situ Ramans pectroscopy.T his work provides spectroscopic evidencet hat the first intermediate of CO 2 reduction on Ag-decoratedC ui s carboxylate anion *CO 2 À bonded with the catalyst surface through the Ca nd Oa tom. The formation and evolution process of the *CO 2 À intermediate over the applied potential are investigated in depth as well. This research contributes to ab etter understanding of the mechanismo fC O 2 reduction and multi-carbon product formation pathways over Agdecorated Cu.

B‐Cu‐Zn Gas Diffusion Electrodes for CO2 Electroreduction to C2+ Products at High Current Densities

“…First, the structural evolution of the catalyst was monitored (Figure 5). Both 0.5 B‐Cu and 0.5 B‐Cu:0.025 Zn GDEs exhibit Raman peaks at 218, 522, and 640 cm −1 , which were ascribed to the Cu 2 O phase [18, 31, 32] . These Raman signals remain essentially unchanged under operando conditions demonstrating the stability of the active Cu + species even at high reduction potentials.…”

“…Operando electrochemistry Raman measurements were additionally used to detect possible intermediates of the eCO 2 RR on 0.5 B‐Cu and 0.5 B‐Cu:0.025 Zn electrodes. The peak at 1072 cm −1 is assigned to the anti‐symmetrical stretching of *OCO, [32, 33] which can be observed from a potential of below −0.23 V vs. RHE and increases in intensity at more cathodic potentials for the 0.5 B‐Cu electrode (Figure 5 A). In contrast, the 0.5 B‐Cu:0.025 Zn electrode already shows a sharp *OCO vibrational peak at a potential of 0.27 V vs. RHE, which gradually weakens at more cathodic potentials (Figure 5 B).…”

“…This implies that the activation of CO 2 can be achieved at more positive potentials for the 0.5 B‐Cu:0.025 Zn electrode additionally supporting the observed higher eCO 2 RR activity for the 0.5 B‐Cu:0.025 Zn electrode as compared with the 0.5 B‐Cu electrode (Figure 4 C). Raman peaks at 283, 344, and 2095 cm −1 for both 0.5B‐Cu and 0.5 B‐Cu:0.025 Zn electrodes correspond to adsorbed CO on Cu, [31–34] which represents the key intermediate for C−C coupling and C 2+ products formation. The peak at about 2713 cm −1 is associated to the C−H vibration [35] and further confirms the formation of hydrocarbons.…”

B‐Cu‐Zn‐Gasdiffusionselektroden für die elektrokatalytische CO2‐Reduktion zu C2+‐Produkten bei hohen Stromdichten

“…Zunächst wurde die strukturelle Entwicklung des Katalysators beobachtet (Abbildung 5). Sowohl die 0,5 B‐Cu‐ als auch die 0,5 B‐Cu:0,025 Zn‐GDEs zeigen Raman‐Peaks bei 218, 522 und 640 cm −1 , die der Cu 2 O‐Phase zugeschrieben wurden [18, 31, 32] . Diese Raman‐Signale bleiben unter Operando‐Bedingungen im Wesentlichen unverändert, was die Stabilität der aktiven Cu + ‐Spezies auch bei hohen Reduktionspotentialen zeigt.…”

Electrochemical Reduction of CO2 at Coinage Metal Nanodendrites in Aqueous Ethanolamine

“…CO 2 is a major contributor to global warming, causing severe impacts on the climate, such as the rise of sea level, droughts, heavy rainfall and snowfall, ocean acidification, and frequent storms [1–4] . Therefore, it is necessary to minimize the emission of CO 2 in the environment and develop sustainable technologies capable of recycling it into valuable products using renewable electricity [5, 6] .…”