A Highly Porous Copper Electrocatalyst for Carbon Dioxide Reduction.

Area of Science:

• Electrochemistry
• Catalysis
• Environmental Science

Background:

• Electrochemical reduction of carbon dioxide (CO2) is a key strategy for mitigating climate change and producing valuable chemicals.
• Developing efficient CO2 electrolysis devices for industrial applications, particularly for C2+ products, remains a significant challenge.

Purpose of the Study:

• To synthesize a nanoporous copper catalyst and integrate it into a microfluidic CO2 flow cell electrolyzer.
• To achieve high current densities and selectivity for C2+ products in CO2 electroreduction.
• To investigate the influence of electrolyte properties on catalyst performance at high current densities.

Main Methods:

• Synthesis of a nanoporous copper catalyst.
• Fabrication and operation of a microfluidic CO2 flow cell electrolyzer.
• Electrochemical measurements including current density and product selectivity analysis.
• Investigation of electrolyte effects, including surface pH measurements.

Main Results:

• The developed CO2 electrolyzer achieved a high current density of 653 mA cm-2.
• A C2+ product selectivity of approximately 62% was obtained at an applied potential of -0.67 V (vs RHE).
• The nanoporous electrode structure facilitated efficient gas transport, enabling high current densities.
• Significant differences between surface and bulk electrolyte pH were observed, especially in non-buffering electrolytes at high currents.

Conclusions:

• The integration of nanoporous copper catalyst in a microfluidic flow cell shows significant promise for efficient CO2 electroreduction to C2+ products.
• The electrode architecture is crucial for managing mass transport limitations at high current densities.
• Understanding and controlling electrolyte properties, particularly surface pH, is vital for optimizing CO2 electrolysis performance.