Electrochemical Ethanol Oxidation using RuO₂‐based Catalysts: Suppressing OER and Tailored Switching between Water Oxidation and Ethanol Oxidation

AbstractFor an efficient hydrogen production, electrochemical ethanol oxidation is a great alternative to the oxygen evolution reaction (OER) due to the generation of value‐added products. In this electrosynthetic contribution, the properties of ethanol oxidation are investigated with regard to the influence of pH, temperature and potential using RuO2‐based catalysts. Results show acetic acid as main reaction product with yields of up to 29 % and Faraday efficiencies of ≥71 %. Increasing the potential marginally from 1.40 V vs. RHE to 1.45 V vs. RHE promoted parasitic OER and, therefore, yield (≥10 %) and Faraday efficiency (≥56 %) of the organic products decreased. Doping RuO2 electrodes with TiO2 shows promising results in suppressing OER during ethanol oxidation. Additionally, the catalyst allows moderate OER potentials in water electrolysis, making the catalyst a switchable material.