The chemical recycling of polyester wastes is of great significance for sustainable development, which also provides an opportunity to access various oxygen-containing chemicals, but generally suffers from low efficiency or separation difficulty. Herein, we report anatase TiO 2 supported Ru and Mo dual-atom catalysts, which achieve transformation of various polyesters into corresponding diols in 100% selectivity via hydrolysis and subsequent hydrogenation in water under mild conditions (e.g., 160 °C, 4 MPa). Compelling evidence is provided for the coexistence of Ru single-atom and O-bridged Ru and Mo dual-atom sites within this kind of catalysts. It is verified that the Ru single-atom sites activate H 2 for hydrogenation of carboxylic acid derived from polyester hydrolysis, and the O-bridged Ru and Mo dual-atom sites suppress hydrodeoxygenation of the resultant alcohols due to a high reaction energy barrier. Notably, this kind of dual-atom catalysts can be regenerated with high activity and stability. This work presents an effective way to reconstruct polyester wastes into valuable diols, which may have promising application potential.
Photocatalytic reforming (PR) of polyester waste, fueled by renewable sources like solar energy, offers a sustainable method for producing clean H 2 and valuable by-products under mild conditions. The design of high-performance photocatalyst plays a pivotal role in determining the efficacy of an alkaline polyester PR system, influencing H 2 generation activity and selectivity. Here, ultrathin porous carbon nitride nanosheets (UP-CN) loaded with Pt nanoclusters (Pt NCs, average diameter of 1.7 nm) with uniform Pt NCs distribution are introduced. The resulting Pt NCs/UP-CN catalyst can accelerate charge and mass transfer while providing additional active sites, achieving superior H 2 generation rates of 11.69 mmol g cat −1 h −1 and 2923 mmol g Pt −1 h −1 under AM 1.5 light, which nine times higher than that of Pt nanoparticles-bulk graphitic carbon nitride composite (1.29 mmol g cat −1 h −1 and 258 mmol g Pt −1 h −1 ) as counterpart. This performance also surpasses that of previously reported carbon nitride-based and TiO 2 -based photocatalysts. Moreover, the density functional theory calculations reveal a significant reduction in the energy barrier for the water dissociation step (H 2 O + * → *H + OH) at the interface between UP-CN and anchored Pt NCs, showcasing the synergistic effect between Pt NCs and UP-CN. This catalytic system also exhibits universality across various polyester plastics.
Hang Lv,Yuandong Huo,Manlu Cheng,Zenghui Diao,Gang Song,Diyun Chen,Lingjun Kong
A kind of high yield and recyclable Cobalt–Carbon composite (Zn 1 Co 5 /P n C) was prepared by carbothermal reduction process, in which the cobalt acetate and zinc acetate were considered as Zn and Co precursors, and the polyester waste was evolved as the carbon precursor. The morphology, structure and composition of the composite were characterized using scanning electron microscopy, X-ray diffraction and X-ray photoelectron spectroscopy. Results showed that evaporation of zinc contributed to the formation of porous carbon structure, and the Co nanoparticles were wrapped and protected by the porous carbon matrix. The Zn 1 Co 5 /P n C activated peroxymonosulfate (PMS) system (Zn 1 Co 5 /P n C/PMS) was constructed to degrade the levofloxacin (LEV). The activity and mechanism of LEV degradation was understood. The LEV degradation efficiency was high to 96.60% within 90 min in the presence of Zn 1 Co 5 /P 4 C. Moreover, the Zn 1 Co 5 /P 4 C still maintained favorable PMS activation performance after five-cycle runs. The results show that the Zn 1 Co 5 /P 4 C played positive role in activating the PMS, it may be due to the facts that the polyester derived carbon could supported the Co while the evaporated Zn could increase the surface area of Zn 1 Co 5 /P 4 C, leading to the increased activity. The possible degradation pathways were proposed by identifying the intermediate products through liquid chromatography-mass spectrometry analysis. This study put forward a promising method to use polyester waste to synthesize high yield cobalt-carbon composite for degrading the antibiotic in wastewater.
危险品化学品经营许可证（带存储）