New insights into the electrochemical conversion of CO2 to oxalate at stainless steel 304L cathode

•Zinc oxalate synthesized in a batch reactor at 2 bar pressure with an average Faradaic efficiency of 73.9%.•Pure oxalic acid extracted from zinc oxalate with 58.2 % efficiency using ester hydrolysis process.•Low water content in the electrolyte solution ∼37 ppm and optimised current density of 15 mA/cm2 enhances oxalate formation.