RESUMEN
The plastic waste issue has posed a series of formidable challenges for the ecological environment and human health. While conventional recycling strategies often lead to plastic down-cycling, the electrochemical strategy of recovering valuable monomers enables an ideal, circular plastic economy. Here a corrosion synthesized single atom Pt1/Ni(OH)2 electrocatalyst with part-per-million noble Pt loading for highly efficient and selective upcycling of polyethylene terephthalate (PET) into valuable chemicals (potassium diformate and terephthalic acid) and green hydrogen is reported. Electro-oxidation of PET hydrolysate, ethylene glycol (EG), to formate is processed with high Faraday efficiency (FE) and selectivity (>90%) at the current density close to 1000 mA cm-2 (1.444 V vs RHE). The in situ spectroscopy and density functional theory calculations provide insights into the mechanism and the understanding of the high efficiency. Remarkably, the electro-oxidation of EG at the ampere-level current density is also successfully illustrated by using a membrane-electrode assembly with high FEs to formate integrated with hydrogen production for 500 h of continuous operation. This process allows valuable chemical production at high space-time yield and is highly profitable (588-700 $ ton-1 PET), showing an industrial perspective on single-atom catalysis of electrochemical plastic upcycling.
RESUMEN
Scandium oxide (Sc2O3) is considered as omnipotent "Industrial Ajinomoto" and holds promise in catalytic applications. However, rarely little attention is paid to its electrochemistry. Here, the first nanocasting design of high-surface area Sc2O3 with abundant oxygen vacancies (mesoporous VO-Sc2O3) for efficient electrochemical biomass valorization is reported. In the case of the electro-oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA), quantitative HMF conversion, high yield, and high faradic efficiency of FDCA via the hydroxymethylfurancarboxylic acid pathway are achieved by this advanced electrocatalyst. The beneficial effect of the VO on the electrocatalytic performance of the mesoporous VO-Sc2O3 is revealed by the enhanced adsorption of reactants and the reduced energy barrier in the electrochemical process. The concerted design, in situ and ex situ experimental studies and theoretical calculations shown in this work should shed light on the rational elaboration of advanced electrocatalysts, and contribute to the establishment of a circular carbon economy since the bio-plastic monomer and green hydrogen are efficiently synthesized.