Boron-bridged AuPt/MBene interfaces enable selective PET electroreforming to formate and hydrogen

초록

Paired electroreforming of polyethylene terephthalate (PET) waste with hydrogen evolution reaction (HER) is a sustainable strategy for coproducing formate and hydrogen. However, its practical implementation remains poorly explored. Herein, as far as we know, we introduce, for the first time, a surface-engineered two-dimensional (2D) molybdenum boride (MoAl1_xB MBene), featuring boron-bridged diffusion channels, derived from MoAlB MAB phases via selective acid etching and delamination, as an electronic support for AuPt alloys. Experimental and theoretical results validate that AuPt/MoAl1_xB, synthesized through a pulsed laser irradiation in liquids process, forms dual catalytic sites with an upshifted d-band center relative to pristine AuPt that modulate the adsorption of *HOCH2CH2OH and *H intermediates. This tailored interface promotes synergistic catalysis for ethylene glycol (EG, a PET monomer) oxidation reaction and HER. AuPt/MoAl1_xB selectively catalyzes EG-to-formate conversion with a Faradaic efficiency of 68.23% at 1.60 V vs. RHE via a glycolaldehydemediated C1 pathway, with glycolate as a minor product. Concurrently, it delivers the HER performance with an ultralow overpotential of 64 mV at 10 mA cm_ 2. Pairing PET hydrolysate oxidation with HER, the Au1Pt1/ MoAl1_xB||Au1Pt1/MoAl1_xB electrolyzer achieves 10 mA cm_ 2 at 1.80 V, 70 mV smaller than that of standard water splitting. Electrolysis of PET hydrolysate for over 100 h at 1.8 V enables high-purity recovery of terephthalic acid and potassium diformate. This study establishes a versatile new class of 2D MBene-based electrocatalytic platform for efficient plastic waste valorization, advancing sustainable strategies for the co-generation of valuable chemicals and fuels.

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