H₂ O₂ Production at Low Overpotentials for Electroenzymatic Halogenation Reactions

Area of Science:

• Biocatalysis
• Electrochemistry
• Materials Science

Background:

• Peroxizymes, enzymes using hydrogen peroxide (H2O2) as an oxidant, are valuable catalysts for oxidation reactions.
• High concentrations of H2O2 can inactivate most peroxizymes, limiting their operational stability.
• Electrochemical in situ generation of H2O2 offers a stable method but often requires high overpotentials, reducing energy efficiency.

Purpose of the Study:

• To develop a method for enhancing the stability and efficiency of peroxizymes using electrochemically generated hydrogen peroxide.
• To reduce the overpotential required for electrochemical H2O2 generation by modifying electrode materials.
• To investigate the performance of a novel gas-diffusion electrode coated with oxidized carbon nanotubes (oCNTs) for electroenzymatic reactions.

Main Methods:

• Coating a gas-diffusion electrode with oxidized carbon nanotubes (oCNTs).
• Performing electroenzymatic halogenation reactions using the modified electrode.
• Comparing the overpotential and product formation rates of the oCNTs-modified electrode with an unmodified electrode.

Main Results:

• The oCNTs-modified electrode significantly reduced the overpotential required for the electroenzymatic halogenation reaction.
• An approximate 100 mV reduction in overpotential was achieved at comparable product formation rates.
• The modified electrode demonstrated improved performance compared to conventional electrode materials.

Conclusions:

• Coating gas-diffusion electrodes with oxidized carbon nanotubes is an effective strategy to lower overpotentials in electroenzymatic reactions.
• This approach enhances the energy efficiency of systems utilizing in situ generated hydrogen peroxide for peroxizyme catalysis.
• The developed method offers a promising pathway for improving the operational stability and applicability of peroxizymes in various oxidation processes.