Phosphorus doping in high-entropy carbides promotes the selectivity in electrooxidation of ethylene glycol to formic acid

Abstract

Plastic waste poses a significant threat to the environment and depletes valuable energy resources and therefore, recycling plastic waste is an urgent global challenge. Herein, we report an electrocatalytic strategy for reforming ethylene glycol (EG), a derivative of polyethylene terephthalate (PET) plastic waste, into high-value commodity chemicals, such as formic acid (FA). Notably, we synthesized the phosphorus-doped high-entropy carbide (P-HEC) catalyst via a combined electrospinning and graphitization process, and it served as an efficient electrocatalyst for FA production via the EGOR. This P-HEC electrocatalyst exhibits excellent performance with a low overpotential of 179 mV vs. RHE at a high current density of 50 mA cm⁻², achieving a high faradaic efficiency (FE) of 89.25% for FA production and yield rate of 136.46 μmol h⁻¹ mg⁻¹. P-HEC nanoparticles (NPs), incorporating Fe, Co, Mn, Mo, Ni and P, showed a modified electronic structure with redistributed local electrons, which would enhance the adsorption of EG, leading to improved catalytic activity and selectivity. This research underscores the feasibility of electrocatalytic reforming of waste PET into valuable products.