Breaking the Adsorption Seesaw Via Asymmetric Pt-M Sites for PET Electro-Upcycling

Electrochemical upgrading of polyethylene terephthalate (PET) waste to high-value glycolic acid (GA) offers a sustainable route for plastic valorization. However, due to the uniform and limited electron density, the adsorption of the key intermediate ethylene glycol (EG) and hydroxyl (OH) on Pt catalysts is restricted by a linear-scaling-governed "see-saw" relationship, which inevitably leads to a fundamental activity bottleneck. Herein, we find that constructing asymmetric nucleophilic - electrophilic Pt - M sites can overcome this bottleneck via coupled electronic and geometric effects. The nucleophilic Pt sites favor the moderate adsorption of EG, while the electrophilic M sites favor OH adsorption, breaking the linear-scaling constraint. The synthesized Pt - Fe nanowires with asymmetric dual sites display breakthrough intrinsic activity with an onset potential of 0.225 V vs. RHE for GA evolution, and achieve energy - effective GA production in a continuous flow electrolyzer with a daily revenue of $258.97/ton in PET upcycling. Operando characterization confirms that the asymmetric construction disrupts the linear adsorption coupling behavior. Importantly, an "asymmetric dual - site electronic - geometric coupling" descriptor is proposed to capture the decoupled adsorption behavior, which is applicable to other Pt - M (Fe, Co, Ni, Pd, Au) catalysts.