Trace Ionic Liquid‐Assisted Orientational Growth of Cu₂O (110) Facets Promote CO₂ Electroreduction to C₂ Products

Abstract

Cu 2 O has great advantages for CO 2 electroreduction to C 2 products, of which the activity and selectivity are closely related to its crystal facets. In this work, density functional theory calculation indicated that the (110) facets of Cu 2 O had a lower energy barrier for the CÀ C coupling compared to the ( 100) and ( 111) facets. Therefore, Cu 2 O(110) facets were successfully synthesized with the assistance of trace amounts of the ionic liquid 1-butyl-3-methylimidazolium ([Bmim]BF 4 ) by a sample wet-chemical method. A high faradaic efficiency of 71.1 % and a large current density of 265.1 mA cm À 2 toward C 2 H 4 and C 2 H 5 OH were achieved at À 1.1 V (vs. reversible hydrogen electrode) in a flow cell. The in situ and electrochemical analysis indicated that it possessed the synergy effects of strong adsorption of *CO 2 and *CO, large active area, and excellent conductivity. This study provided a new way to enhance the C 2 selectivity of CO 2 electroreduction on Cu 2 O by crystal structure engineering.

Role of Ionic Solvents in the Electrocatalytic CO2 Conversion and H2 Evolution Suppression: From Ionic Liquids to Deep Eutectic Solvents

“…Very recently, it has been proved that the design of the Cu-based electrocatalyst, for instance by tuning the growth of specific crystallographic planes using ionic solvents, has allowed to promote the CO 2 RR to C 2 products such as ethanol and ethylene. [123] Apart from the relevance of ionic solvents in the cathodic material synthesis, they are able to stabilize ionic metallic species in solution. This is particularly relevant in the case of DES, thanks to the large amount of chloride anions present in their composition.…”

Recalibrating the Experimentally Derived Structure of the Metastable Surface Oxide on Copper via Machine Learning-Accelerated In Silico Global Optimization

“…On the other hand, through various studies, it has been reported that another O/Cu(111) surface oxide exists, which has been proposed as a metastable state. It is referred to as the “8” structure and possesses motifs resembling the zigzag shape of Cu 2 O­(110), in contrast to the hexagonal motifs found in the other surface oxides on Cu(111) which resemble the surface geometry of Cu 2 O­(111). − When considering that the Cu 2 O­(110) surface is identified to be photocatalytically active for CO 2 reduction to methanol , and has enhanced C 2 selectivity, an accurate atomic structure determination of the “8” surface oxide is important. It may also lead to additional insights concerning the advantageous active sites and mechanisms for the CO 2 reduction reaction.…”