Block Copolymer Particle-Templated Cavitated Carbons Achieve Local Alkalinity for Enhancing Acidic Electrochemical...

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Electrochemical CO2 reduction (CO2RR) in neutral/alkaline media is limited by carbonate formation, reducing CO2 utilization.
• Acidic conditions favor CO2RR but are dominated by the hydrogen evolution reaction (HER).

Purpose of the Study:

• To develop a catalyst that enables selective CO2RR under acidic conditions.
• To investigate the effect of catalyst microenvironment on CO2RR performance.

Main Methods:

• Synthesis of gold catalysts supported on cavitated carbon particles (CCP) and solid carbon particles (SCP).
• Evaluation of catalysts using flow cell experiments at pH 2.
• Multi-physics simulations to analyze the local reaction environment within catalyst cavities.

Main Results:

• Cavitated carbon particles (CCP) sustain elevated local alkalinity within their cavities.
• The confined cavity geometry (∼130 nm diameter) significantly suppresses HER and enhances CO2RR.
• Modulation of the microenvironment via binder, cation identity, and concentration further optimized performance.

Conclusions:

• Cavity confinement is a powerful strategy to modulate local reaction environments for catalysis.
• This approach enables selective CO2RR under highly acidic conditions, offering a viable pathway for efficient CO2 electrolysis.