Journal of Cleaner Production
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2023
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IF 11.1
Geliang Xie,Guoqiang Zhu,Yifan Kang,Mingxu Zhu,Qianqian Lu,Chao He,Lujiang Xu,Zhen Fang
Realizing the recovery and valorization of waste polyethylene terephthalate (PET) plastics into value-added products have gained significant importance. This study successfully synthesized aromatic nitriles , specifically terephthalonitrile (TPN), from waste polyethylene terephthalate (PET) plastic through in situ catalytic pyrolysis with urea and γ-Al 2 O 3 catalyst. Based on distributed activation energy model, positive interaction between waste PET and urea is responsible for improved thermal decomposition kinetics. The dosage of urea and pyrolysis temperature significantly influenced TPN production. TPN yield reached 32.5% with ca. selectivity of 85% at 550 °C and equivalent urea dosage. Density functional theory calculations validated the role of active ammonia in reducing energy barriers and thus facilitating PET depolymerization . The study highlights the feasibility of recycling waste PET into valuable aromatic nitriles through in situ catalytic pyrolysis with urea and enhances the understanding of the pyrolysis process.
研究领域:
材料科学
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化学工程
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产品关联
DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
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2025
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IF 4.3
Chunrui Rong,Dongxia Yan,Jiabao Li,Jian Feng,Jiayu Xin,Qing Zhou,Yi Li,Junli Xu,Xingmei Lu
The increase in the usage of polyethylene terephthalate (PET) leads to the generation of a large amount of waste, which may cause carbon emissions and waste of petroleum resources. The methanolysis method has attracted global attention, but limited by high reaction temperature and excessive use of methanol. We report here an efficient catalyst, tetramethylguanidine/1,5-diazabicyclo[4.3.0]-5-non-ene (TMG/DBN), converting waste PET into regenerated dimethyl terephthalate (rDMT) under 100 °C with almost equivalent methanol, achieving 100 % PET conversion and 93.1 % yield of rDMT. A series of analytical methods and theoretical calculations were used to reveal the enhanced interaction between the catalyst and reactants, which facilitates the degradation of PET at low methanol dosages. In addition, a kinetic model was also developed with a relatively low activation energy of 84.9 kJ/mol. This work provides an effective strategy for the up-grading recycling of waste PET under mild reaction conditions.
研究领域:
材料科学
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环境科学
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化学工程
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产品关联
DOI
高影响因子
Journal of Environmental Chemical Engineering
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2025
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IF 7.2
Lu Li,Sihong Xu,Liang Jin,Wenxing Chen,Shichang Chen
It is essential to find a depolymerization system with good catalytic activity, easy operation, and high efficiency for the degradation of waste PET. The synergistic catalytic effect of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) and zinc 2-ethylhexanoate (ZnEH) in PET glycolysis was investigated. Waste PET can be more efficient when completely degraded than single organocatalyst or zinc salt or previous DBU/Zn(OAc) 2 , and the yield of BHET reaches 84.1 % under optimal reaction conditions with the molar ratio of 2:1 of DBU to ZnEH and the weight ratio of 3:1 of EG to PET, the temperature of 180 °C and at 60 minutes. By combining experimental results with density functional theory (DFT) calculations, the synergistic enhancing degradation mechanism that generates hydrogen and coordination bonds is proposed. The purified depolymerization product of BHET was repolymerized to PET, delightfully the r-PET was almost identical to virgin PET.
研究领域:
材料科学
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环境科学
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化学工程
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产品关联
DOI
高影响因子
RSC Advances
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2016
·Vol. 6
·期 54
·48737-48744
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IF 3.289
Danfeng Hou,Jiayu Xin,Xingmei Lu,Xiaonan Guo,Huixian Dong,Baozeng Ren,Suojiang Zhang
1,4-Cyclohexanedimethanol (CHDM) is a highly valued and widely used monomer in the polymer industry. Bis(2-hydroxyethylene terephthalate) (BHET), the product of glycolysis of waste PET, is an excellent raw material for the preparation of CHDM. Herein, a series of monometallic, bimetallic and trimetallic supported catalysts were prepared for the one-pot conversion of BHET into CHDM by the impregnation method and good performance was found over trimetallic RuPtSn/Al2O3 catalysts containing various active sites to catalyze the hydrogenation of the phenyl and carbonyl groups. The influences of various reaction parameters including temperature, pressure and time on the hydrogenation reaction were studied, and 100% conversion and 87.1% yield of CHDM were obtained with the trimetallic supported catalyst with Ru/Sn 1.5. Moreover, through the comparison between various methods for the preparation of CHDM, the conversion of BHET into CHDM by the one-pot method is considered one of the most competitive methods.
研究领域:
化学工程
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材料科学
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催化反应
✓ 已验证
DOI
高影响因子
ChemSusChem
·
2023
·Vol. 16
·期 9
·e202300154
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IF 8.4
Yuheng Lin,Deshuai Yang,Chaoyu Meng,Chunying Si,Quanxing Zhang,Guixiang Zeng,Wei Jiang
Graphical Replace the atom : Ni 2+ -doped MgO catalyst is developed via a combined theoretical and experimental approach, which exhibits excellent performance toward the glycolysis of polyethylene terephthalate (PET) with a bis(hydroxyethyl) terephthalate yield of 93.7 %. Ni 2+ doping is found critical to the generation of O − and deprotonated ethylene glycol which break the PET chain via nucleophilic attack. Developing efficient and eco-friendly catalysts for selective degradation of waste polyethylene terephthalate (PET) is critical to the circular economy of plastics. Herein, we report the first monatomic oxygen anion (O − )-rich MgO−Ni catalyst based on a combined theoretical and experimental approach, which achieves a bis(hydroxyethyl) terephthalate yield of 93.7 % with no heavy metal residues detected. DFT calculations and electron paramagnetic resonance characterization indicate that Ni 2+ doping not only reduces the formation energy of oxygen vacancies, but also enhances local electron density to facilitate the conversion of adsorbed oxygen into O − . O − plays a crucial role in the deprotonation of ethylene glycol (EG) to EG − (exothermic by −0.6 eV with an activation barrier of 0.4 eV), which is proved effective to break the PET chain via nucleophilic attack on carbonyl carbon. This work reveals the potential of alkaline earth metal-based catalysts in efficient PET glycolysis.
研究领域:
材料科学
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催化
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环境科学
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化学工程
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DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
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2023
·Vol. 140
·期 31
·e54238
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IF 3
Li Liu,Panpan Hao,Ruiqi Zhang,Yujin Zhang,Qing Zhou,Xingmei Lu,Dongxia Yan,Yi Li,Chunyan Shi
Products obtained by alcoholysis of waste PET are promising raw materials for the synthesis of polyurethane elastomers (PUEs). Alcoholysis of PET by low molecular weight diols such as ethylene glycol yields low molecular weight products. The latter need to be polymerized to high molecular weight polyols which are subsequently used as soft segments for the synthesis of PUEs. This work aims to look for suitable high molecular weight diols for the alcoholysis of waste PET to yield high molecular weight products which can be directly used as soft segments for the synthesis of PUEs. This approach allows to save the polymerization step for the formation of high molecular weight polyols. Specifically, polyester diols such as polycaprolactone diol (M n = 2000) were used for the alcoholysis of waste PET. The resulting PUEs exhibited very good mechanical properties: a tensile strength of up to 40.95 MPa, an elongation at break of up to 1219%, and a toughness of up to 237 MJ·m −3 , along with good transparency and thermal stability.
研究领域:
材料科学
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聚合物化学
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环境工程
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产品关联
DOI
高影响因子
JOURNAL OF POLYMERS AND THE ENVIRONMENT
·
2024
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IF 4.7
Yang Ge,Wu Hao,Huang Ke,Ma Yukun,Chen Qi,Chen Yun,Lin Shanshan,Guo Hailing,Li Zhibo
The recycling of polyethylene terephthalate (PET) waste plastics has garnered global attention as an essential area of research to address. Chemical upcycling methods, such as glycolysis, offers a visible solution by directly converting PET wastes into high-valued monomers, enabling their reintegration into the plastic life cycle. However, the recovery of metal salt catalyst and the thermal stability of organic catalyst pose challenges in PET glycolysis. Zeolites with strong Brønsted acid are widely used in the degradation of polyolefins, but in PET glycolysis, they face the problems of acid site mismatch and difficult contact with PET. In this work, nanosized FAU-type zeolite catalysts (100-FAU) were employed to carry out PET glycolysis, which were green synthesized at low temperature without organic template. In comparison to commercial FAU-type catalysts, 100-FAU exhibits enhanced Lewis acidity and basicity along with increased accessibility to active sites. The 100% degradation of PET was achieved within 1 h, resulting in a BHET yield of 64.2%. Prolonging the reaction time to 1.5 h led to an enhanced BHET yield of 72.1%. The quality of the primary product bis(2-hydroxyethyl) terephthalate (BHET) was verified through IR, DSC, and NMR characterizations. Furthermore, as a solid catalyst with high thermal stability, zeolite can be easily recovered via filtration and demonstrated stable performance over at least 5 cycles, and proved effective for glycolysis of commercially waste PET plastics. The acid–base dual-functional catalytic mechanism of Na-form FAU in PET glycolysis was proposed. Under its guidance, the promoting effect of other Na-form nanosized zeolites on PET degradation was verified.
研究领域:
材料科学
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化学工程
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环境科学
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催化
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）