Plasma-Assisted Synthesis of Oxygen-Deficient Pt-Ni(OH)2/NF for Coupled Hydrogen Evolution and Electro-Reforming of PET Plastic

Coupling the hydrogen evolution reaction (HER) with PET-derived ethylene glycol oxidation reaction (EGOR) offers an energy-saving route for hydrogen production and plastic upcycling. However, Pt-based bifunctional catalysts are limited by inefficient Pt utilization, nonideal H* adsorption, and anodic oxidation-induced deactivation. Here, we report an oxygen-deficient D-Pt-Ni(OH)2/NF catalyst prepared by dielectric barrier discharge plasma treatment and integrated with an alternating-pulse electrolysis strategy. Plasma treatment introduces abundant oxygen vacancies and promotes electron transfer from Ni to Pt, downshifting the Pt d-band center and optimizing H* adsorption. The optimized catalyst requires only 12 mV to reach 10 mA cm–2 for HER and delivers a Pt mass activity of 3.23 A mg–1Pt at –0.1 V vs RHE, which is 64.6 and 1.68 times higher than those of Pt/C and untreated Pt-Ni(OH)2/NF, respectively. In an HER||EGOR electrolyzer, D-Pt-Ni(OH)2/NF achieves 100 mA cm–2 at 0.96 V using PET hydrolysate. Alternating-pulse electrolysis suppresses Pt oxidation and enables stable 100 h operation in a membrane-free flow electrolyzer, with >90% Faradaic efficiency for glycolic acid and nearly 100% Faradaic efficiency for H2. Techno-economic analysis indicates a net profit of $1080.1 per ton of PET processed. This work demonstrates a catalyst–electrolysis co-engineering strategy that links plasma-induced electronic modulation with durable plastic valorization-assisted hydrogen production.