Strong p−d orbital hybridization on PdSn metallene for enhanced electrooxidation of plastic-derived alcohols to glycolic acid

Abstract

Electrochemical reforming of polyethylene terephthalate (PET) waste into fine chemicals is regarded as a sustainable upgrading cycle process for waste resource re-utilization. Nevertheless, it is challenging to produce valuable C2 chemicals via the electrocatalytic oxidation of PET waste derived ethylene glycol (EG) due to the undesirable over-oxidation of EG. Here, PdSn metallene is synthesized by hydrothermal method for electrochemical upgrading of PET plastics hydrolysate, achieving a high Faradaic efficiency of 92.45% for the production of glycolic acid (GA) at 0.97 V. The metallene structure can provide sufficient exposed active sites and excellent electron transfer rate for electrolysis. Furthermore, the incorporation of Sn into Pd induces strong p–d orbital hybridization, thereby modulating the electronic structure of the active sites. This orbital hybridization effectively optimizes the adsorption energy of intermediates and strengthens the bond energy of C−C bond and another hydroxyl group, ultimately enhancing the catalytic activity and selectivity for GA production. This study presents a powerful p–d orbital hybridization guidance for the development of efficient catalysts towards efficient conversion of PET plastics into valuable C2 products.