Selective CO₂ Electroreduction to Multi-Carbon Products on Organic-Functionalized CuO Nanoparticles by Local...

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis
• Sustainable Chemistry

Background:

• Surface functionalization of copper-based catalysts is a promising strategy to improve electrochemical CO2 reduction reaction (CO2RR) towards multi-carbon (C2+) products.
• Existing methods often focus on suppressing hydrogen evolution and concentrating CO2/CO at the electrode surface.
• Developing catalysts for efficient C2+ production in neutral electrolytes remains a significant challenge.

Purpose of the Study:

• To develop surface-functionalized catalysts with enhanced activity and selectivity for electrocatalytic CO2RR to C2+ products in a neutral electrolyte.
• To investigate the mechanism by which surface functionalization influences CO2RR pathways and C-C coupling.
• To demonstrate the performance of these catalysts in both flow cells and membrane electrode assembly (MEA) electrolyzers.

Main Methods:

• Synthesis of CuO nanoparticles coated with hexaethynylbenzene organic molecules (HEB-CuO NPs).
• Electrochemical evaluation in a flow cell setup and a membrane electrode assembly (MEA) electrolyzer.
• In-situ spectroscopy and molecular dynamics simulations to elucidate reaction mechanisms.

Main Results:

• Achieved nearly 90% C2+ Faradaic efficiency at 300 mA cm−2 and maintained >80% FE across 100–600 mA cm−2 in a neutral electrolyte flow cell.
• Demonstrated 86.14% FE_C2+ at 387.6 mA cm−2 in an MEA electrolyzer, with sustained operation over 50 hours at 200 mA cm−2.
• Spectroscopic and simulation studies indicated that reduced coordinated K⋅H2O coverage promotes CO interaction and C-C coupling, enhancing C2+ yield.

Conclusions:

• Surface functionalization of CuO NPs with HEB molecules significantly enhances electrocatalytic CO2RR to C2+ products in neutral media.
• The developed catalysts exhibit high activity, selectivity, and stability under industrially relevant conditions.
• This work provides a pathway for optimizing catalyst micro-environments for efficient and sustainable C2+ production.