The electrosynthesis of ethylene oxide in a tandem recycle flow reactor system

•A tandem recycle system for ethylene oxide electrosynthesis was developed.•Faradaic efficiencies of 80.2 ± 6% and 46.7 ± 4.5% were achieved in 0.5 M and 3 M KBr anolyte respectively.•Ethylene oxide concentrations up to 10 g/L were achieved during experiments of 6 up to 10 h.•Parasitic oxygen evolution and overoxidation of hydrocarbons were not observed at the anode.•Iridium oxide based anodes were pretreated at 450 °C in air to improve stability.