Fig. 4: The importance of CoO_x/IrO₂ in the electrocatalyst:mediator assembly.

Faradaic efficiencies of anodic toluene oxidation with electrocatalyst:mediator assemblies comprising a commercial electrocatalysts and b IrO₂-based electrocatalysts. All error bars represent standard deviation based on three independent samples. The reaction was run in a H-type cell, in which 0.5 mL toluene was dissolved in 19.5 mL of anolyte comprising 0.1 M LiBF₄ and 0.06 M LiNO₃ in acetonitrile solution. The catholyte is 20 mL of 0.1 M LiBF₄ MilliQ water (18.2 Ω) solution. The anolyte and catholyte were separated with a Nafion® 117 membrane. c EPR spectra of the anolyte with electrocatalyst:mediator assemblies comprising IrO₂-based electrocatalysts. d Adsorption energies of the NO₃^● radical on the IrO₂(100)-O_v, CoO_x/IrO₂(100)-O_v and Co₃O₄(100) slabs. Side views of the NO₃^● radical adsorbed on the e, Co and f, Ir atom of CoO_x/IrO₂(100)-O_v. Source data for Fig. 4a-c are provided as a Source Data file.