Figure 2.

PFV (ν=5 mV s⁻¹) showing A) reversible reduction of CO₂ to formate by mesoITO|FDH (blue trace) and B) CO₂ reduction by mesoTiO₂|FDH before (blue) and after 2 h CPE (black). Inset: CPE at −0.6 V vs. SHE. Conditions for A and B: 43 pmol FDH (amount drop‐cast), 100 mm CO₂/NaHCO₃, 50 mm KCl, 20 mm formate (only present in A), 1 atm CO₂, pH 6.5, 25 °C, Pt counter electrode. Dashed traces show control experiments of FDH‐free electrodes.