H2O2 Production at Low Overpotentials for Electroenzymatic Halogenation Reactions

Various enzymes utilize hydrogen peroxide as an oxidant. Such “peroxizymes” are potentially very attractive catalysts for a broad range of oxidation reactions. Most peroxizymes, however, are inactivated by an excess of H2O2. The electrochemical reduction of oxygen can be used as an in situ generation method for hydrogen peroxide to drive the peroxizymes at high operational stabilities. Using conventional electrode materials, however, also necessitates significant overpotentials, thereby reducing the energy efficiency of these systems. This study concerns a method to coat a gas‐diffusion electrode with oxidized carbon nanotubes (oCNTs), thereby greatly reducing the overpotential needed to perform an electroenzymatic halogenation reaction. In comparison to the unmodified electrode, with the oCNTs‐modified electrode the overpotential can be reduced by approximately 100 mV at comparable product formation rates. Low and behold: Coating of a gas‐diffusion electrode with oxidized carbon nanotubes (oCNTs) is found to greatly reduce the overpotential needed to perform an electroenzymatic halogenation process. In comparison to the unmodified electrode, with the oCNTs‐modified electrode the overpotential can be reduced by around 100 mV at comparable product formation rates.