Oxygen depolarised cathode as a learning platform for CO2 gas diffusion electrodes

Scientists and engineers worldwide are developing carbon dioxide utilisation technologies to defossilise the bulk chemical industry and support global efforts toward net-zero targets. Electrolysis can make oxygenate and hydrocarbon products from CO2, water, and renewable electricity. Opposed to such striking simplicity, CO2 electrocatalysis and electrolysers are fraught with challenges hampering the deployment of CO2 electrolysis on a large scale. The chlor-alkali electrochemical industry has already tackled various issues encountered today in the development of stable CO2 reduction gas diffusion electrodes (GDEs). The oxygen depolarised cathode (ODC) is a very stable GDE currently used to make multiple kilotonnes of NaOH and Cl-2. In this review, we present the principle of operation of the ODC including bespoke cell designs implemented to deliver year-long process stability. We do this in parallel to discussing the needs of CO2 electrolysis and close with a proposed CO2 electrolyser design integrating the learning from the development of the chlor-alkali ODC. The rationale is to help advance robust CO2 electrolysis with industrially relevant performance.

Automated summary

Scientists and engineers worldwide are developing carbon dioxide utilisation technologies to support net-zero targets; the experience from the chlor-alkali electrochemical industry can help address challenges in CO2 electrolysis.