Journal of Environmental Chemical Engineering
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2023
·
IF 7.7
Wenxia Hou,Yi Li,Shuting Xu,Qian Wang,Kuntong Song,Junhong Liu,Nan Wang,Qing Zhou,Dongxia Yan,Xingmei Lu
The usage of zinc-containing catalysts in glycolysis causes the residue of Zn 2+ in the polyethylene terephthalate (PET) degradation monomer bis-hydroxyethyl (BHET), which limits the high-value utilization of BHET. This work first used electrodeposition combined with one-time recrystallization to purify BHET. Electrodeposition was suitable for dealing the Zn 2+ concentrations of degradation solutions within 50–100 ppm, and decreased the content of Zn 2+ in BHET from 141.30 to 2.41 ppm, which reached the standard of repolymerization into PET bottles. The removal rate of Zn 2+ was 90 % for the degradation solutions, which decreased the concentration of Zn 2+ in wastewater from 100 to 8.97 ppm. Meanwhile, the Zn 2+ removed from the degradation solutions was deposited on cathode, which obtained metal Zn materials and realized the recycling of Zn resources from Zn(OAc) 2 . Therefore, electrodeposition could realize the purification of BHET, recycling of Zn(OAc) 2 , reducing the environmental pollution caused by the emission of Zn 2+ and the protection of human health, simultaneously. Electrodeposition had less water consumption, lower loss rate of BHET (from 60 % to 10 %) and shorter processing time, compared with six-times recrystallizations. This study first proposed the formation of quadridentate between BHET and Zn 2+ , and put forward a new three-steps electrodeposition mechanism of Zn 2+ : the addition of electric field destroyed the dissociation equilibrium of quadridentate and made it shift to release free Zn 2+ ; the free Zn 2+ gathered to form ionic groups and they migrated to copper; Zn 2+ reduced on copper, of which the first step was the speed limited step.
研究领域:
化学工程
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环境科学
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DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2023
·Vol. 47
·期 9
·4337-4345
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IF 3.3
Zhangbin Liao,Yunlong Duan,Liying Guo,Rongrong Zheng,Liyan Wang,Yanming Chen,Linnan Zhang,Xin Qian
Five titanium-centered heteropoly acids with different metal vacancies were prepared first, and then combined with an ionic liquid by ion exchange to prepare heteropoly acid ionic liquid catalysts Bmim4–6[M(H2O)TiMo11O39] (M = Cu2+, Fe2+, Pb2+, Ti4+, and Zn2+). The structure and thermal properties of each catalyst were tested and analyzed by Fourier transform infrared (FTIR) spectroscopy, ultraviolet (UV) spectroscopy, X-ray powder diffraction (XRD), apparent morphology analysis, and thermogravimetric analysis (TGA). Five heteropoly acid ionic liquids were investigated by using waste mineral water bottles as samples for performance in the catalytic degradation of bottle-grade polyethylene terephthalate (PET), and the degradation product, bis(2-hydroxyethyl) terephthalate (BHET), was analyzed for the chemical structure. The results showed that the five heteropoly acid ionic liquid catalysts were successfully prepared, with good thermal stability. Of these catalysts, Bmim4[Ti(H2O)TiMo11O39] showed the optimal catalytic performance. It achieved an alcoholysis rate of 100% and a yield of BHET of 84.73% with a catalyst dosage of 0.6% (percentage in the total mass of the raw materials) at 190 °C for 5 h. Moreover, after six cycles of use, the alcoholysis rate was still as high as 94.36%, and the yield of BHET was 75.65%. The above results indicated that the prepared heteropoly acid ionic liquid catalysts showed good performance in the catalytic degradation of bottle-grade PET, presenting a promising prospect for development.
研究领域:
化学
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材料科学
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环境科学
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DOI
高影响因子
CATALYSIS TODAY
·
2024
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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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DOI
高影响因子
Journal of Environmental Chemical Engineering
·
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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DOI
高影响因子
Catalysis Science & Technology
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2023
·Vol. 13
·期 22
·6561-6569
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IF 5
Songlei Mo,Yong Guo,Xiaohui Liu,Yanqin Wang
The glycolysis of polyethylene terephthalate (PET) is considered as the most promising PET recycling strategy due to its mild reaction conditions and circularity. Herein, several metal-doped SBA-15 (M/SBA-15) as heterogeneous Lewis acid catalysts were investigated to screen the best catalyst and to understand the essence for their differences in PET glycolysis. It is found that the catalytic activity is positively correlated with the acid amount in different metal-doped SBA-15 and Ti/SBA-15 with different Ti loadings, with the exception of Nb/SBA-15. 4Ti/SBA-15 with abundant Lewis acid sites shows excellent PET glycolysis ability, with the yield of bis(2-hydroxyethyl) terephthalate (BHET) reaching 87.2% within 45 min at 190 °C (isolated yield 73%). While 4Nb/SBA-15 has a similar acid amount as that in 4Ti/SBA-15, but it has very low catalytic activity probably due to its strong oxygen affinity. Acetone–methanol-adsorption DRIFTS confirms its strong oxygen affinity, which would poison the acid sites by ethylene glycol (EG) and result in very low activity. This study demonstrates that PET glycolysis activity is really correlated with the amount of Lewis acid sites, but species with very strong oxygen affinity would lower its activity. Further diffuse reflection ultraviolet-visible (DR UV-vis) spectra analysis confirms that tetrahedral Ti4+ species in Ti/SBA-15 is the real active center. In addition, 4Ti/SBA-15 has good reusability and can be used in common real PET (dyed polyester fabric, PET bottles) glycolysis. These results indicate that increasing the amount of Lewis acid sites is a promising way to enhance PET glycolysis and 4Ti/SBA-15 with high activity and stability is a potential catalyst for industrial application.
研究领域:
材料科学
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催化化学
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环境科学
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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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PubMed
高影响因子
RSC Advances
·
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
NEW JOURNAL OF CHEMISTRY
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2023
·Vol. 47
·期 31
·14646-14655
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IF 3.3
Ruiyang Wen,Guoliang Shen,Jinmiao Zhai,Linghui Meng,Yunlong Bai
Acetylacetone titanium oxide (TiO(acac)2) was synthesized from acetylacetone and isopropyl titanate via a one-pot method. The catalyst's structure and morphology were characterized and analyzed using FT-IR, UV–vis, XRD, SEM, and laser particle size analysis. The prepared acetylacetone titanium oxide was used for the alcoholysis reaction of polyethylene terephthalate (PET), and the yield of bis(hydroxyethyl) terephthalate (BHET) obtained from the alcoholysis reaction was taken as the index. The optimal conditions for the alcoholysis reaction were determined using response surface methodology: 3 g of PET, a catalyst dosage of 0.467%, a temperature of 200.5 °C, a time of 3.77 h, and 13.50 mL of ethylene glycol, with a BHET yield of 96.41%. The model had good reliability. Finally, the reaction mechanism was speculated, and the catalyst was compared with other catalysts. The TiO(acac)2 catalyst has a good application prospect.
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
ACS Sustainable Chemistry & Engineering
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2022
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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
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
CATALYSIS LETTERS
·
2021
·Vol. 152
·期 4
·1182-1193
·
IF 3.186
Shi Kaiyu,Guo Liying,Zheng Rongrong,Wang Haiyue,Chen Yanming
Five kinds of diacid comprising ionic liquid catalyst [HO 3 S–(CH 2 ) 4 -mim]Cl–MCl x ] were prepared, and their chemical structure, thermal stability and acidity were tested and analyzed. The performance evaluation of catalysts was carried out, and the process parameters were optimized. The cycling stability of the catalysts was investigated. Then, the catalytic degradation of polyethylene terephthalate (PET) was studied, and used mineral water bottles as an example. The chemical structure and molecular weight of the degradation product terephthalic acid bis(2-hydroxyethyl) ester (BHET) were analyzed. The results showed that among the catalysts synthesized, [HO 3 S–(CH 2 ) 4 -mim]Cl–FeCl 3 had the great catalytic performance and good thermal stability. According to the thermal gravimeter analysis, the decomposition temperature of the diacid ionic liquid catalyst ranges from 400 to 560 °C, while the degradation reaction temperatures in this paper are all below 250 °C, so that it has good thermal stability. At 190 °C, the PET alcoholysis rate reached 98.7% and the BHET yield reached 95.5% for 6 h, and the highest catalytic activity could still be maintained after 6 cycles, which indicate that the catalyst has excellent performance for degrading PET, and will have a great application prospect. Graphic Abstract
研究领域:
化学工程
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材料科学
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产品关联
DOI
高影响因子
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
·
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
危险品化学品经营许可证（带存储）