Engineering Orbital Spin on Cobalt Nickel Diselenides for Efficient Ethylene Glycol Electrooxidation

Electrocatalytic ethylene glycol oxidation (EGOR) is central to energy conversion andpolyethylene terephthalate (PET) plastics upcycling, yet its deployment is limited by thescarcity of selective, durable anodes. We report cobalt nickel diselenide (Co1-xNixSe2)nanoparticles (NPs) prepared by hydrothermal synthesis, where Ni incorporationmodulates the spin states of Co and tailors the electronic structure. In situ Fouriertransform infrared spectroscopy identifies glycolaldehyde and glyoxylic acid as keyintermediates, revealing a Ni-induced shift toward a C–C bond-cleavage pathway. Anequimolar Ni/Co composition delivers ≈90% Faradaic efficiency (FE) to formate at 1.6 Vversus RHE while sustaining ~100 mA cm-2 over 10 h testing. The enhanced activity andselectivity arise from spin-state optimization, which strengthens adsorption of reactionintermediates, promotes selective dehydrogenation and controlled C–C scission, andsuppresses over-oxidation. These results establish spin-state engineering as an effectivelever to steer the electrooxidation pathways of small organic molecules and guide thedesign of high-performance anode catalysts.