Enhancing the Selectivity of Cu₂O-Based Catalysts for Multicarbon Products via Interface Engineering

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Electrochemical CO2 reduction (CO2RR) is crucial for sustainable chemical production.
• Copper-based catalysts are promising for CO2RR, but achieving high C2+ selectivity remains a challenge.
• Understanding the roles of different copper oxidation states (Cu+ and Cu0) is key to catalyst design.

Purpose of the Study:

• To synthesize Cu2O/Cu heterostructure catalysts with well-defined interfaces.
• To investigate the interfacial effects on CO2RR performance, particularly C2+ product selectivity.
• To elucidate the reaction mechanism at the Cu2O/Cu interface.

Main Methods:

• Synthesis of Cu2O/Cu heterostructures via chemical reduction of octahedral Cu2O.
• Electrochemical evaluation in H-cell and flow cell setups.
• In situ ATR-FTIR spectroscopy, CO2/CO cofeeding experiments, and DFT calculations.

Main Results:

• The optimized 360-Cu2O/Cu catalyst achieved high C2H4 Faradaic efficiency (FE) of 30.7% and total C2+ FE of 44.3% in an H-cell.
• In a flow cell, the C2+ FE reached 53.2% at a current density of 50 mA cm-2.
• Cu2O/Cu interfaces were shown to enhance CO2 activation and reduce energy barriers for key C-C coupling steps.

Conclusions:

• Cu2O/Cu heterostructures with defined interfaces are effective catalysts for CO2RR to C2+ products.
• The Cu2O/Cu interface plays a critical role in promoting C2+ selectivity by facilitating CO2 activation and C-C coupling.
• This work provides insights into designing advanced electrocatalysts for efficient CO2 conversion.