The ligand effect of graphene quantum dots in NiFeOx/FeNi3 heterostructure for enhanced electrocatalytic valorization of poly(ethylene terephthalate) plastics
Bo Peng, Sheng Qian, Shuhui Ma, Yi Zhang, Huaiguo Xue, Tengfei Jiang, Jingqi Tian
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引用次数: 0
Abstract
Electrocatalytic valorization of disused poly (ethylene terephthalate) (PET) plastics into value-added chemicals emerges as a potential approach to address plastic pollution and resources upgrading, but it faces challenges in the development of efficient catalysts for PET-derived ethylene glycol (EG) electrooxidation. Herein, we proposed pyramid arrays on sheet Fe-doped NiO/FeNi3 (SPA-NiFeOx/FeNi3) heterostructure, which is derived from the pyrolysis of MOF-on-MOF heterostructure growth triggered by graphene quantum dots (GQDs). Such SPA-NiFeOx/FeNi3 exhibits superior catalytic performance on the electrooxidation of EG (EGOR) from PET hydrolysate, with a formic acid (FA) selectivity of 91.5% and a Faradaic efficiency of 92%. The ligand effect of GQDs in both the catalyst design and improved electrocatalytic performance was studied with combined spectroscopy analysis and theoretical calculations, which revealed that such spatially separated NiFeOx and FeNi3 components by GQDs possess more active sites to anticipate in electrocatalytic EGOR, and the large sp2 domains in GQDs possess a strong electron-withdrawing ability to reduce the electron density of bonded Ni and Fe, resulting in high-valenced Niδ+/Feδ+ in FeNi3 and Ni(2+δ) in NiO, respectively. Furthermore, the coordination number of Ni and Fe centers was lowered due to the steric effect of GQDs. Therefore, the adsorption of EG on Niδ+ for cascade dehydrogenation and C–C bond cleavage led to adsorbed FA that transferred to adjacent Fe for desorption, which was promoted by the enrichment of OH− on nearby Ni(2+δ) sites, along with optimized Gibbs free energy change in the multistep reaction pathway. This work provides an efficient multi-active-site catalyst for disused PET plastics valorization, thereby presenting a new approach to enhance the efficiency of PET plastics valorization reactions.
期刊介绍:
The Journal of Energy Chemistry, the official publication of Science Press and the Dalian Institute of Chemical Physics, Chinese Academy of Sciences, serves as a platform for reporting creative research and innovative applications in energy chemistry. It mainly reports on creative researches and innovative applications of chemical conversions of fossil energy, carbon dioxide, electrochemical energy and hydrogen energy, as well as the conversions of biomass and solar energy related with chemical issues to promote academic exchanges in the field of energy chemistry and to accelerate the exploration, research and development of energy science and technologies.
This journal focuses on original research papers covering various topics within energy chemistry worldwide, including:
Optimized utilization of fossil energy
Hydrogen energy
Conversion and storage of electrochemical energy
Capture, storage, and chemical conversion of carbon dioxide
Materials and nanotechnologies for energy conversion and storage
Chemistry in biomass conversion
Chemistry in the utilization of solar energy