Killing Two Birds with One Stone: Selective Oxidation of Small Organic Molecule as Anodic Reaction to Boost CO2 Electrolysis

Replacing anodic oxygen evolution reaction (OER) with the oxidation of small organic molecules in CO2 electrolysis is an ingenious strategy to reduce the energy consumption while produce valuable anodic products instead of low-value O-2. Herein, an advanced CO2 electrolysis system constructed by replacing OER with selective methanol oxidation reaction (MOR) is reported as a proof-of-concept, which achieves the yielding of value-added products in both cathode and anode. Notably, the MOR over a self-supported NiCo-based metal-organic framework-derived anode (NiCo-NF-ET) only needs 1.291 V to reach a high current density of 100 mA cm(-2), which is about 346 mV lower than that of OER. Simultaneously, formate can also be produced with the Faradaic efficiencies approaching to 100%. Consequently, in comparison with the conventional CO2 electrolysis system, integrating cathodic CO2 reduction reaction (CO2RR) with anodic MOR can lead to the reduction of about 880 mV to deliver the current density of 30 mA cm(-2), while without compromising the selectivity of the products in both electrodes. Herein, the great potential to increase the economic benefits of CO2 electrolysis via the rational design of nonprecious electrocatalysts and participated anodic oxidation reactions is shown.

Automated summary

This study presents an advanced CO2 electrolysis system constructed by replacing OER with selective methanol oxidation reaction (MOR), achieving the production of value-added products in both the cathode and anode. The integration of CO2RR and MOR can reduce energy consumption and improve the economic benefits of CO2 electrolysis without compromising product selectivity.