Ampere-Level Upgrading of Polyethylene Terephthalate to Glycolate Using Palladium–Copper/Nickel Hydroxide Electrocatalysts

Electrocatalytic upgrading of waste plastics with concurrent hydrogen production offers a promising path toward carbon neutrality. Nevertheless, achieving high efficiency and selectivity in converting plastic-derived ethylene glycol (EG), particularly at industrially relevant current densities above 200 mA cm–2, remains challenging. In this study, we present a nickel hydroxide-supported palladium–copper alloy catalyst, PdCu/Ni(OH)2, which demonstrates a large current density of 2 A cm–2 at 1.22 V, and a high glycollate (GA) Faradaic efficiency of 97.7% at 500 mA cm–2. In situ experiments and computational simulations reveal that the PdCu alloy and the terminal −OH functional group of Ni(OH)2 synergistically enhance the adsorption of *COCH2OH intermediates and facilitate the generation of *OH species. This combination effectively prevents overoxidation, improves CO antipoisoning, and accelerates the EG-to-GA conversion kinetics. When the catalyst is assembled in a photovoltaic (PV) driven HER//EGOR system, a solar-to-hydrogen efficiency of 38.0% is achieved with EG as a sacrificial agent. This work provides an effective catalyst design strategy for the electrochemical and photoelectrochemical upgrading of waste polyethylene terephthalate plastics.