Background
Electrochemical CO2 reduction at the cathode is typically coupled with the oxygen evolution reaction (OER) at the anode. OER accounts for >90 % of electrical energy consumed by the CO2 electrolyser. Developing alternative anodic reactions other than OER to enhance the overall energy and process efficiency would be transformative.
Outcomes
A new strategy for replacing OER with organic compound oxidation will deliver a step-change in the energy efficiency and economics of CO2 electrolysers. A range of high-performance catalysts will be developed to greatly improve reactions, and novel flow-based electrolyser systems will be developed. Critical to the circular carbon economy, alternative chemical feedstocks will be established, consequently having a broad impact on manufacturing, agronomy and retail sectors.
FP3: Development of alternative anodic oxidation reactions for coupling with CO2 electroreduction
Program Lead – Professor Chaun Zhao
Traditionally, CO2RR at the cathode is coupled with anodic oxygen evolution reactions (OER). However, OER accounts for most of the energy consumption in the CO2 electrolysis system, but its product, oxygen is of low value and is released into the air. Therefore an opportunity exists for energy efficiency and technoeconomic improvement if oxygen evolution can be replaced by the production of valuable chemicals instead. Furthermore, can anodic oxidation reaction be utilised to improve the product selectivity? This flagship project will develop alternative anodic oxidation reactions using biomass-derived organic compounds, such as alcohols, glycerol and HMF which are abundant in Australia, to enhance CO2 electrolyser efficiency and produce value-added chemicals to further improve the technoeconomics. Novel catalysts will be developed for AOR, GOR, and HMFOR and their reaction mechanisms will be understood by electrochemical, microscopic, spectroscopic and X-ray characterisations as well as theoretical calculations. The hybrid CO2RR electrolyser prototypes will be demonstrated and evaluated in flow cell and membrane electrode assembly (MEA) configurations. The energy efficiency and technoeconomics will be established and compared with traditional oxygen evolution reaction-based CO2RR system.