Long-term-stability continuous flow CO2 reduction electrolysers with high current efficiency

Abstract

One of the intrinsic problems relating to electrolysers for the electrochemical carbon dioxide reduction reaction is that the water-based liquid electrolyte induces the hydrogen evolution reaction. Here, we report an electrolyser based on a polymer electrolyte membrane and assisted by a high-performance advanced carbon-supported gold nanoparticle catalyst. By adjusting the mass ratio of gold in the catalyst, CO formation with up to 97% current efficiency was achieved at a cell potential of 2.7 V with 105 mA cm⁻² partial current efficiency for CO production. The electrolyser has extremely high stability for 130 hours at 50 mA cm⁻² with greater than 95% current efficiency and 55% energy efficiency for CO production. This work shows the great potential of using small-sized Au nanocatalysts with low gold content for the electrochemical reduction of CO₂ in a full-cell. This strategy sheds light on the scale-up and further development of CO₂ electrolysers aiming towards commercialization.