Electrooxidation of Ethylene Glycol to Glycolic Acid with Pt-Ni(OH)2 Catalysts: High Efficiency and Selectivity for PET Plastics Upgrading

The electroconversion of polyethylene terephthalate (PET) into C2 fine chemicals and hydrogen (H2) presents a promising solution for advancing the circular plastics economy. In this study, we report the electrooxidation of ethylene glycol (EG) to glycolic acid (GA) using a Pt-Ni(OH)2 catalyst, achieving a high Faraday efficiency (>90%) even at high current densities (250 mA cm-2 at 0.8 V vs. RHE). Notably, this catalyst outperforms most existing Pt-based catalysts in terms of catalytic activity. Experimental analyses reveal that: 1) Ni(OH)2 enhances the adsorption of OH- ions and promotes the rapid generation of *OH active species, which are essential for the efficient oxidation of EG to GA; 2) the oxygenophilic nature of Pt improves EG adsorption, and in synergy with Ni, accelerates the oxidation process. Furthermore, Pt lowers the electrolysis potential, preventing excessive oxidation and ensuring high selectivity for GA. This work offers a promising pathway for the electrooxidation-based upgrading of PET plastics and provides valuable insights for future research in this area.