Membrane-Free Electrolysis for Low-Voltage Production of 2,5-Furandicarboxylic Acid

Electrolysis powered by renewable electricity has the potential to defossilize chemical production; however, existing electrolyzer configurations are hampered by high operating voltages and, consequently, large electricity costs. In this work, we demonstrate that anode reaction alterations can provide new options for device engineering to drive low-voltage electrolysis. By conducting the electrosynthesis of a valuable bioplastic precursor 2,5-furandicarboxylic acid (FDCA), from 5-hydroxymethylfurfural (HMF) at the anode, we showed that O2 production could be avoided, enabling the construction of a membrane-free reactor for high-rate electrolysis (j > 500 mA cm–2). We demonstrate that tuning reaction conditions and adapting the device configuration for a membrane-free setup enabled the system to achieve a current density of 500 mA cm–2 with a full-cell voltage <1.5 V. This validation of the design and operation of membrane-free electrolyzers for high-value chemical production paves the way for extension and application of such architectures in emerging sustainable technologies.