Electro-upcycling polyethylene glycol aqueous solutions in a proton exchange membrane electrolyser

作者：N. Grimaldos-Osorio, Essyllt Louarn, Chantal Lorentz, Fabrizio Sordello, Monica Passananti, Olivier Boyron, Manel Taam, Vincent Monteil, Jesús González‐Cobos, A. Caravaca, P. Vernoux · 发表于：Electrochimica Acta · 年份：2024 · DOI：10.1016/j.electacta.2024.145524 · 被引用次数：3 · 研究领域：Recycling and Waste Management Techniques、Fuel Cells and Related Materials、Extraction and Separation Processes

• Polyethylene glycol (PEG) can be electrooxidized at low potential on a Pt/C anode. • Size-exclusion chromatography and NMR demonstrate the depolymerization of PEG. • Mass spectrometry confirms the production of pure hydrogen at the cathode. • Proof-of-concept for upcycling PEG aqueous solutions in a PEM electrolyser. This study addresses the electro-upcycling, at low temperature and neutral pH conditions, of aqueous solutions of polyethylene glycol (PEG). For this purpose, a Proton-Exchange Membrane (PEM) reactor with Pt/C-based electrodes has been used. The electrooxidation performances of ethylene glycol (EG) and PEG were evaluated for various concentrations in aqueous solutions, temperatures and PEG molecular weights (MW). PEG was successfully electro-oxidized from 0.4 V, reaching current densities above 100 mA cm -2 at 0.8 V and 80 °C using oligoethylene glycols up to 400 g mol -1 . Size-exclusion chromatography and NMR analysis evidenced the possibility to cleave –C–O–C– bonds of heavy PEG (1000, 4000 g mol -1 ), proving the possibility of depolymerizing PEG and recovering the monomer at low cell voltages and low temperatures. The production and purity of hydrogen in the cathode compartment of the electrolyser was confirmed by mass spectrometry. These results may open new perspectives in the development of electro-upcycling of PEG in water effluents.