A long-term-stable continuous flow electrochemical ozone generator with high current efficiency

Abstract

Renewable-energy-powered electrochemical ozone production (EOP) by water splitting is an eco-friendly and promising technology. An ozone generator with long-term stable operation, high ozone output, and low production energy is therefore desired. Herein, an electrolyser based on a polymer electrolyte membrane and assisted by a high-performance advanced nano PbO₂ gas diffusion electrode was investigated. In this work, by comparing the catalyst supports of the PbO₂ gas diffusion electrode and adjusting the catalyst polymeric binders and catalyst loading content, O₃ formation with up to 20% current efficiency was achieved at a cell potential of 3.2 V with 150 mA cm⁻² partial current density for O₃ generation. The electrolyser with a nano PbO₂ anode has extremely high stability for 500 hours at 300 mA cm⁻² with 23% current efficiency for O₃ generation. This work shows the great potential of nano PbO₂ membrane electrodes for electrochemical ozone production by water splitting in a full-cell. The strategy sheds light on the possibility of scale-up from the lab scale to industrial production and further development of ozone generators aiming towards commercialization.