Ethylene Selectivity in Electrocatalytic CO₂ Reduction on Cu Nanomaterials: A Crystal Phase-Dependent Study

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• The crystal phase of metal nanocatalysts is crucial for catalytic performance.
• Copper-based nanomaterials are effective electrocatalysts for CO2 reduction reaction (CO2RR) to produce hydrocarbons.
• Previous research focused primarily on the conventional face-centered cubic (fcc) phase of copper.

Purpose of the Study:

• To synthesize and investigate the catalytic behavior of unconventional crystal phases of copper (4H and 4H/fcc) for CO2RR.
• To compare the CO2RR performance of these novel copper phases with the conventional fcc phase.
• To elucidate the mechanism behind the enhanced catalytic activity and selectivity.

Main Methods:

• Synthesis of high-purity 4H Cu and heterophase 4H/fcc Cu using 4H and 4H/fcc Au as templates.
• Electrocatalytic evaluation of CO2RR performance, focusing on activity and ethylene selectivity.
• Density functional theory (DFT) calculations to understand the role of crystal phase and interfaces.

Main Results:

• Successfully synthesized high-purity 4H Cu and 4H/fcc Cu nanomaterials.
• The unconventional 4H and 4H/fcc Cu phases exhibited enhanced overall activity for CO2RR.
• These novel phases demonstrated significantly higher selectivity towards ethylene (C2H4) production compared to fcc Cu.
• DFT calculations confirmed that the 4H phase and 4H/fcc interface promote C2H4 formation.

Conclusions:

• Crystal phase engineering is vital for optimizing nanocatalyst performance in electrocatalytic reactions.
• Unconventional crystal structures, specifically 4H and 4H/fcc Cu, offer improved CO2RR activity and ethylene selectivity.
• This work provides a new strategy for designing advanced catalysts with tailored properties for various applications.