Identification of Cu(100)/Cu(111) Interfaces as Superior Active Sites for CO Dimerization During CO₂ Electroreduction

Abstract

The electrosynthesis of valuable multicarbon chemicals using carbon dioxide (CO 2 ) as a feedstock has substantially progressed recently but still faces considerable challenges. A major difficulty lines in the sluggish kinetics of forming carbon−carbon (C−C) bonds, especially in neutral media. We report here that oxide-derived copper crystals enclosed by six {100} and eight {111} facets can reduce CO 2 to multicarbon products with a high Faradaic efficiency of 74.9 ± 1.7% at a commercially relevant current density of 300 mA cm −2 in 1 M KHCO 3 (pH ∼ 8.4). By combining the experimental and computational studies, we uncovered that Cu(100)/Cu(111) interfaces offer a favorable local electronic structure that enhances *CO adsorption and lowers C−C coupling activation energy barriers, performing superior to Cu(100) and Cu(111) surfaces, respectively. On this catalyst, no obvious degradation was observed at 300 mA cm −2 over 50 h of continuous operation.

A Porous π–π Stacking Framework with Dicopper(I) Sites and Adjacent Proton Relays for Electroreduction of CO2 to C2+ Products

“…As a crucial segment of industrial production, the manufacture of C 2+ products ( e.g. , C 2 H 4 , EtOH, AcOH, and PrOH) plays an important role in economy. − Recently, electrochemical CO 2 reduction (ECR) has attracted much attention thanks to its potential application for the production of hydrocarbons and carbon oxygenates, − especially C 2+ compounds, and the achievement of carbon neutrality. − However, electrochemical production of C 2+ compounds generally suffers from poor stability, product selectivity and efficiency, and the reaction mechanism still remains to be explored . Therefore, the design and preparation of new electrocatalysts for yielding C 2+ products should be regarded as one of the most important challenges for the application of ECR.…”

Mechanistic Insights into OC–COH Coupling in CO2 Electroreduction on Fragmented Copper

“…Previously, the CO dimerization has been suggested as a plausible pathway for C–C bond formation, − which was also confirmed by online electrochemical mass spectroscopy or by observing *OCCO intermediates via time-resolved attenuated total reflection-surface enhanced infrared absorption spectroscopy (ATR-SEIRAS) . However, the discussion about other possible pathways is still open. , Recently, density functional theory (DFT) calculations suggested the formation of C–C bonds via an OC–COH coupling pathway is thermodynamically and kinetically more favorable than CO dimerized into OCCO. , When optimizing the Cu–CO interaction on a Au-doped Cu(100) or the CO coverage on Cu(100), the OC–COH coupling can be promoted over the competitive CO dimerization.…”

Synergistic effect of Cu/Cu2O surfaces and interfaces for boosting electrosynthesis of ethylene from CO2 in a Zn–CO2 battery

“…5a). It can be observed that there are obvious CO* characteristic peak bands in the spectra from −0.4 to −1.2 V ( vs. RHE), and the peak bands located at 2140–2150 cm −1 are attributed to the interface stretching vibrational modes of the adsorption of CO. 50 These results reveal that the surface/interface of Cu/Cu 2 O promotes CO dimerization and C 2 products. Density functional theory (DFT) calculations also better revealed the unique activity and selectivity of the CO 2 RR.…”