Electro-Reforming of PET Plastic to C2 Chemicals with Concurrent Generation of Hydrogen and Electric Energy

Upcycling poly(ethylene terephthalate) (PET) waste into valuable C2 products presents an alternative avenue for attaining carbon neutrality. In this study, we introduce a C–C preserved pathway for selectively transforming waste PET-derived ethylene glycol (EG) into glycolic acid (GA), a 25-fold value of C2 product. Utilizing a Pt–Ni(OH)2/NF electrode, EG oxidation reaction (EGOR) proceeds at a remarkably low potential (100 mA cm–2 @0.69 V vs reversible hydrogen electrode (RHE)) with an impressive Faraday efficiency (93%) for GA production. In situ Fourier transform infrared (FTIR) measurements are employed to pinpoint crucial reaction intermediates, elucidating C2 pathways for the conversion of EG to GA. Quasi in situ electron paramagnetic resonance (EPR) experiments identify rich •OH species in Pt–Ni(OH)2, making the active Pt sites less susceptible to be poisoned through oxidative removal of adsorbed carbonyl intermediates during EGOR. Density functional theory (DFT) calculations underscore the synergistic interplay between Pt and Ni(OH)2, optimizing the adsorption/desorption of intermediates on metal sites and ensuring heightened activity, selectivity, and stability in EGOR. Furthermore, we propose an innovative electro-forming architecture by integrating EGOR with the hydrogen evolution reaction (HER) and oxygen reduction reaction (ORR). This hybrid architecture is activated by the multifunctional catalytic electrode Pt–Ni(OH)2/NF and deployed throughout the day by a switch mode. It can achieve high-value chemical production from PET hydrolysate with concurrent hydrogen generation and electric energy output, offering an appealing multifaceted solution to waste PET plastic upcycling.