CATALYSIS TODAY
·
2024
·
IF 5.2
Lin Gao,Zixian Jia,Lijiao Qin,Haocheng Sun,Xinwei Zhang,Baozhong Li,Xuehai Wang,Jiquan Liu,Jinbo Bai
The recovery of Zn/ZnO nanoparticles from spent alkaline batteries was studied. This catalyst was employed for glycolysis of polyethylene terephthalate (PET) to produce bis(2-hydroxyethyl) terephthalate (BHET). The reaction temperature, catalyst/PET ratio and reaction time were investigated. Under the optimal conditions of 190 ℃ and 2 hours, with a catalyst/PET ratio of 2 %, the PET conversion rate and BHET yield of this process were 99 % and 81 %, respectively. The experimental results show that the catalyst exhibits high catalytic activity, is easy to separate, and has good reusability. In addition, this catalyst can deal effectively with impurities and dyes present in waste PET. Finally glycolysis kinetic studies were conducted on the reaction of PET degradation, and the activation energy of 118.8 kJ·mol −1 were obtained.
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
·
2025
·
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
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2026
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IF 8.7
Cui-Can Lu,Qing-Song Huang,Wen-Jing Zheng,Xiao-Min Zhao,Tian-Tian Wang,Yan Huang,Jing Wu,Zheng-Fei Yan
BHETase_B exhibited higher activity toward BHET than PET and MHET. • Half-lives of engineered BHETase_B (>5.0 h) was greater than WT at 50 °C. • Mutant Q7I/A106P achieves complete degradation of BHET within 2 h at 50 °C. • Mutant Q7I/A106P plus TurboPETase can synergistically degrade PET. Polyethylene terephthalate (PET) plastic waste poses significant environmental challenges. Enzymatic degradation of PET offers a sustainable recycling route, but intermediate products such as bis (2-hydroxyethyl) terephthalate (BHET) and mono (2-hydroxyethyl) terephthalate (MHET) can inhibit further hydrolysis. A bis (2-hydroxyethyl) terephthalate hydrolase (BHETase_B) from Stenotrophomonas pavanii exhibited hydrolytic activity toward both BHET and MHET, but its poor thermal stability limited industrial application. In this study, a combination of rational design and directed evolution strategies were employed to generate BHETase_B mutants, all of which exhibited significantly improved thermal stability with half-lives greater than 5.0 h at 50 °C, compared to the wild type (<1.5 h). Notably, mutant Q7I/A106P demonstrated a 7.6 °C increase in melting temperature (Tm = 52.5 °C for the wild type) and achieved complete degradation of BHET within 2 h at 50 °C. Mutant Q7I/A106P alone showed limited activity toward solid PET, but significantly enhanced product release when combined with PET hydrolases, especially TurboPETase, releasing 206.1 μM of products, a 1.4-fold increase compared with TurboPETase alone. These findings highlighted the potential of the engineered BHETase_B mutant as a downstream auxiliary enzyme for improving cascade PET degradation. Download: Download high-res image (155KB) Download: Download full-size image
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DOI
PubMed
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
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DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
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2024
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IF 4.1
Jin-Tao Du,Hao Wu,Yao Jie,Yi Xia,Zhenyu Yang,Hong Yan,Qian Wang,Jie-Xin Wang,Jian-Feng Chen
Efficient and sustainable recycling of polyethylene terephthalate (PET) is essential in mitigating its environmental impacts on climate, human health, and global ecosystems. Glycolysis, a closed-loop recycling method that converts PET into bis(2-hydroxyethyl) terephthalate (BHET), stands out as one of the most promising methods due to its mild operating conditions and environmentally friendly nature. However, the complete convert PET into BHET with a high stability are still challenging. In this study, magnetically recyclable CoFe 2 O 4 nanocatalysts were synthesized by the solvothermal method and surface-modulated with Na 3 Cit·2H 2 O as a modifier. When utilizing an optimized CoFe 2 O 4 catalyst, conversion of PET achieved 100 %, with a BHET yield of 91.7 % at 210 °C for 1 h. The excellent catalytic performance of CoFe 2 O 4 is attributed to its smaller particle size, improved dispersion, higher surface Co/Fe ratio, and increased oxygen vacancies, all of which can be achieved through straightforward surface modulation. DFT calculations of M−O distance (M = Co or Fe), adsorption energy, and Bader charges confirm that a higher surface Co/Fe ratio enhanced PET glycolysis, consistent with experimental results. Additionally, a modified energy economy coefficient ( ε m ) was proposed to characterize the catalytic efficiency. The ε m value of CoFe 2 O 4 -60 % was 0.624, indicating promising applications in efficient PET glycolysis. This work presents a versatile approach for easily manipulating the surface properties of magnetic catalysts and identifies key factors for achieving high performance in PET-to-BHET conversion. It offers valuable guidelines for the future design of nanoparticle catalysts with magnetic properties for chemocatalytic reactions.
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
ACS Sustainable Chemistry & Engineering
·
2022
·
IF 9.224
Zishuai Wang,Yu Jin,Yaoqiang Wang,Zequn Tang,Shaojie Wang,Gang Xiao,Haijia Su
Due to the antibiodegradable properties, numerous plastics have been accumulated in the ecosystem and aggravate ecological pollution. Poly (ethylene terephthalate) (PET) is among the most used plastics. Glycolysis of PET is a useful approach to solve the waste PET pollution and obtain bis(2-hydroxyethyl) terephthalate (BHET). In this paper, waste PET was efficiently depolymerized through glycolysis catalyzed by cyanamide. In particular, compared with the previously reported catalyst, cyanamide is more readily available and can be used directly in catalysis without a complex preparation process. Under optimal conditions, PET was completely depolymerized with up to nearly 100% BHET yield. Even at a temperature as low as 150 °C, a good BHET yield can be obtained. The application potential of this glycolysis procedure was demonstrated by its excellent performance in the glycolysis of various real PET wastes like transparent and opaque PET samples and polyester foam and by the high quality of the obtained BHET products. The mechanism was studied by 1H NMR analysis, and DFT calculations showed that the higher activity of cyanamide than its trimer, melamine, is due to the stronger hydrogen bonds formed between cyanamide and PET or ethylene glycol.
研究领域:
环境科学
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材料化学
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催化反应
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DOI
高影响因子
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
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2024
·
IF 5.7
Sizhong Feng,Mengke Xue,Fang Xie,Hongyang Zhao,Yemin Xue
The gene-encoding carboxylesterase (TM1022) from the hyperthermophilic bacterium Thermotoga maritima (T. maritima) was cloned and expressed in Escherichia coli Top10 and BL21 (DE3). Recombinant TM1022 showed the best activity at pH 8.0 and 85 °C and retained 57% activity after 8 h cultivation at 90 °C. TM1022 exhibited good stability at pH 6.0–9.0, maintaining 53% activity after incubation at pH 10.0 and 37 °C for 6 h. The esterase TM1022 exhibited the optimum thermo-alkali stability and kcat/Km (598.57 ± 19.97 s–1mM–1) for pN–C4. TM1022 hydrolyzed poly(ethylene terephthalate) (PET) degradation intermediates, such as bis(2-hydroxyethyl) terephthalate (BHET) and mono(2-hydroxyethyl) terephthalate (MHET). The Km, kcat, and kcat/Km values for BHET were 0.82 ± 0.01 mM, 2.20 ± 0.02 s–1, and 2.67 ± 0.02 mM–1 s–1, respectively; those for MHET were 2.43 ± 0.07 mM, 0.04 ± 0.001 s–1, and 0.02 ± 0.001 mM–1 s–1, respectively. When purified TM1022 was added to the cutinase BhrPETase, hydrolysis of PET from drinking water bottle tops produced pure terephthalic acids (TPA) with 166% higher yield than those obtained after 72 h of incubation with BhrPETase alone as control. The above findings demonstrate that the esterase TM1022 from T. maritima has substantial potential for depolymerizing PET into monomers for reuse.
研究领域:
生物化学
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环境科学
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微生物学
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DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
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2024
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IF 12.2
Weitao Ou,Han Wang,Yingdan Ye,Huaiyuan Zhao,Yibin Zhang,Zhaoyin Hou
Chemical upcycling of waste polyethylene terephthalate (PET) to value-added products can reduce the emission of CO 2 , microplastics and toxic chemicals. In this work, mesoporous H-type Zeolite Socony Mobil-5 (HZSM-5) supported Ru catalyst (Ru/ m -HZSM-5) was synthesized and tested in the hydrogenation of PET degraded chemicals (bis(2-hydroxyethyl) terephthalate , dimethyl terephthalate, diethyl terephthalate, and terephthalic acid). Characterizations disclosed that Ru/ m -HZSM-5 catalyst possesses mesopores (a dominant channel of 5.32 nm), enlarged specific surface area (404 m 2 ·g −1 ), and Ru NPs dispersed highly (40.6 %) compared to that of Ru/HZSM-5. And also, it was found that Ru/ m -HZSM-5 was capable for the hydrogenation of benzene rings in these PET degraded chemicals with large sizes (1.09–1.82 nm). In particular, the conversion of BHET and the selectivity of BHCD over Ru/ m -HZSM-5 reached 95.5 % and 95.6 % at 120 °C within 2 h. And Ru/ m -HZSM-5 could be recycled at least five times without obvious loss of activity and selectivity.
研究领域:
化学工程
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环境科学
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材料科学
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产品关联
DOI
PubMed
高影响因子
ACS Sustainable Chemistry & Engineering
·
2024
·
IF 7.1
Anamika Kushwaha,Lalit Goswami,Beom Soo Kim
In this study, we established an innovative and integrated chemical/biological methodology for the complete poly(ethylene terephthalate) (PET) degradation and biopolyol production using cerium–iron oxide nanoparticles (CeFeNPs). Initially, three nanoparticles, i.e., CeNPs, FeNPs, and CeFeNPs, were synthesized and evaluated for PET glycolysis. CeFeNPs demonstrated the best catalytic performance for PET depolymerization to bis(2-hydroxyethyl) terephthalate (BHET) and were further recovered from the PET depolymerized slurry to be reutilized again. BHET was further biodegraded using the hydrocarbonoclastic bacterium Pseudomonas aeruginosa PR3 under the batch modes using a shake flask and a stirred tank bioreactor. To elucidate the fate of BHET biodegradation under aerobic conditions, identification of various BHET degraded metabolites was carried out using liquid chromatography–mass spectrometry analysis. The strain could produce an extracellular diol synthase enzyme, which transforms oleic acid into the biopolyol, 7,10-dihydroxy-8(E)-octadecenoic acid (DOD). CeFeNPs were further supplemented to enhance DOD production via whole cell and cell-free approaches.
研究领域:
环境科学
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生物化学
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材料科学
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产品关联
DOI
高影响因子
ACS Sustainable Chemistry & Engineering
·
2025
·
IF 7.3
Chenjing Qu,Xiaolong Han,Haiyun Wang,Ruidong Wang,Yifei Zhang,Weiwei Sun,Ziqian Shi,Yuting Wang,Penggang Yin
The widespread use of poly(ethylene terephthalate) (PET) has led to severe environmental pollution and significant resource depletion. The depolymerization of waste PET into bis(2-hydroxyethyl) terephthalate (BHET) offers considerable potential for chemical recycling. Although conventional glycolysis faces challenges such as low degradation efficiency and high energy requirements, an efficient catalytic method was developed herein to convert postconsumer PET into BHET under milder conditions. The incorporation of the cosolvent dimethyl sulfoxide (DMSO) into the reaction system reduced the degradation temperature to 150 °C, significantly lower than the temperature observed without cosolvents, which exceeded 190 °C. Under optimized conditions, the combination of a metal catalyst and the organic nitrogen heterocycle 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) enabled complete depolymerization of PET within 90 min, yielding BHET at 80.11%. In addition, the recrystallized product was repolymerized into PET, enabling closed-loop resource recycling. Life cycle assessment (LCA) indicates that this closed-loop approach is not only technically feasible but also environmentally beneficial, reducing energy consumption by approximately 64.54% and greenhouse gas emissions by 37.32%. This strategy offers a practical low-carbon solution for the sustainable recycling of waste PET.
研究领域:
高分子化学
·
催化
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绿色化学
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废弃物回收
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材料科学
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产品关联
DOI
高影响因子
RSC Sustainability
·
2025
·
IF 4.9
ZIXIAN JIA,JIE ZHANG,LIN GAO,LIJIAO QIN,HAOCHENG SUN,JIAXING CHEN,Jian-Zhong Yin
The chemical recycling of polyethylene terephthalate (PET) via glycolysis is a promising route for recovering the monomer bis(2-hydroxyethyl) terephthalate (BHET), which can be used for virgin-grade PET production. However, the influence of water—an inevitable impurity and potential byproduct—on this process is complex and not fully elucidated. This study systematically investigates the effect of water content (0–22.2 vol%) on PET glycolysis using selected heterogeneous catalysts (ZnO, Mn₂O₃) and homogeneous catalysts (zinc acetate (ZnAc₂), 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD), and 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU)). Product distribution and reaction kinetics were quantified by HPLC and in-situ IR spectroscopy, respectively.The heterogeneous catalysts (ZnO, Mn₂O₃) and homogeneous ZnAc₂ maintained high PET conversion (>95%) even at elevated water concentrations. Nevertheless, the BHET yield and selectivity for these systems decreased significantly due to a competing hydrolytic side reaction, promoted by water, which yields terephthalic acid (TPA). Notably, ZnAc₂ exhibited a more rapid decline in BHET selectivity compared to ZnO. Conversely, the organic base catalysts TBD and DBU experienced complete deactivation in the presence of water, resulting in a drastic reduction in both PET conversion and BHET yield, with DBU showing greater susceptibility. In-situ IR experiments corroborated that the deactivation mechanism for TBD involves protonation by water. These results emphasize that water's influence is a function of the catalyst's chemical nature, modulating product selectivity for metal-based systems while causing the deactivation of organic bases. Understanding these divergent effects is critical for the optimization of industrial PET glycolysis and the rational design of water-tolerant catalytic systems.
研究领域:
高分子化学
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催化化学
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化学回收
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反应工程
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环境化学
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材料科学
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产品关联
DOI
高影响因子
JOURNAL OF POLYMERS AND THE ENVIRONMENT
·
2024
·
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
·
化学工程
·
环境科学
·
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）