Reaction Chemistry & Engineering
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2025
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IF 3.1
Xueqian Zhang,Jiasong Yan,Shuai Yuan,Shanqing Yu,Qingyu Liu,Xikai Wang,Rui Li
Whether cycloalkanes undergo six- or five-membered ring-opening reaction pathways remains controversial. In this work, the catalytic cracking reactions of cyclohexene and 1-methylcyclopentene, as model compounds, were investigated in a pulse microreactor. The characteristics of the reactions of the two model compounds were compared in terms of isomerization, cracking, and hydrogen transfer reaction, and the reasons for the differences in their catalytic reactions were analyzed in combination with thermodynamic and molecular simulation calculations. The results have shown that the catalytic cracking product distributions of cyclohexene and 1-methylcyclopentene were similar owing to their easy mutual isomerization; the five-membered ring-opening cracking pathway was more thermodynamically advantageous than that of six-membered ring-opening cracking, and therefore, the yield of the ring-opening cracking product of 1-methylcyclopentene was comparatively higher; the main products of the hydrogen transfer reaction of the two compounds were alkanes and aromatic hydrocarbons. By comparing the product distributions and reaction activation energies, the ring-opening reaction pathways were clarified, and the catalytic cracking reaction networks of cyclohexene and 1-methylcyclopentene were established.
研究领域:
化学
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催化反应
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DOI
高影响因子
Polymer Chemistry
·
2021
·Vol. 12
·期 46
·6694-6704
·
IF 5.582
Yu Liu,Weichen Sheng,Ren Yin,Kan Zhang
Aniline is a very common amine source for benzoxazine synthesis, but it generally results in relatively high ring-opening polymerization temperatures. The exploration of alternative amine sources to lower the polymerization temperature of benzoxazine resins is a prerequisite for further development of high performance polybenzoxazines. In this work, three propargyl-containing benzoxazine monomers with different numbers of oxazine rings (PH-pa, BA-pa and TH-pa) have been synthesized using phenol/bisphenol-A/1,1,1-tris(4-hydroxyphenyl)ethane, propargylamine, and paraformaldehyde as the starting materials. The structures of these benzoxazines are characterized using NMR, FT-IR and HR-MS spectra, which indicate the successful incorporation of the reactive oxazine ring and the propargyl group into the molecular structure of each monomer. In addition, the polymerization behavior of each benzoxazine has been monitored by in situ FT-IR spectroscopy and differential scanning calorimetry (DSC), which shows that each resin can be completely polymerized through complex polymerization mechanisms including the ring-opening polymerization of the oxazine ring and additional ethynyl polymerization. Moreover, the thermal stability and the flammability of the resulting thermosets have been investigated by thermogravimetric analysis (TGA) and micro-scale combustion calorimetry (MCC), respectively. Notably, the thermoset derived from TH-pa exhibits the highest thermal stability with a peak degradation temperature of 418 °C and a char yield value of 50.2% at 800 °C in nitrogen. It also exhibits the lowest heat release capacity (87.0 J g−1 K−1) and total heat release value (17.4 kJ g−1) among the newly obtained polybenzoxazines.
研究领域:
材料科学
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化学工程
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DOI
高影响因子
POLYMER BULLETIN
·
2020
·Vol. 78
·期 8
·4403-4417
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IF 2.014
Zhu Yongfei,Li Peilin,Lin Runsheng,Su Junming
Both pyrogallol-furfurylamine-based and pyrogallol-aniline-based di-benzoxazines (PG-FA and PG-A) possess a free hydroxyl and latent catalytic characteristics. To decrease the ring-opening polymerization (ROP) temperature of benzoxazine based on phenol and 4,4′-diaminodiphenylmethane (P-DDM) and increase simultaneously thermal property of its polymer, PG-FA and PG-A as catalysts were introduced into P-DDM. DSC and FTIR tests were used to investigate the effect of PG-FA and PG-A on the ROP of P-DDM; DMA, FTIR and TGA were performed to study their effects on the hydrogen bonds and thermal property of the cured P-DDM (PP-DDM). The results indicate that the ROP temperature of P-DDM remarkably decreased with the incorporation of PG-FA and PG-A. FTIR and DMA results illustrate that the total amounts of hydrogen bonds in PP-DDM increased with the addition of PG-FA or PG-A; however, its fraction of –OH⋯N (intra) and O − ⋯ + HN (intra) hydrogen bonds decreased. The decrease in –OH⋯N hydrogen bonds made the cross-linked density of polybenzoxazine increase, resulting in that the thermal stability of PP-DDM enhanced with the introduction of PG-FA and PG-A.
研究领域:
材料科学
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化学工程
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高影响因子
Catalysis Science & Technology
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2022
·Vol. 12
·期 19
·5879-5890
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IF 6.177
Dengfeng Dai,Chao Feng,Minmin Wang,Qingzhou Du,Dandan Liu,Yuan Pan,Yunqi Liu
Biomass-based chemicals as a renewable alternative to petroleum-based chemicals are of great significance. The conversion of biomass-based furfuryl alcohol to pentanediol, including 1,5-pentanediol and 1,2-pentanediol, is explored over a series of bifunctional Cu/MFI catalysts in a continuous-flow reactor. These catalysts are synthesized by supporting copper nanoparticles on MFI zeolites with varying molar ratios of SiO2/Al2O3. Among them, the Z60-10Cu catalyst containing balanced Cu0–Cu+ and Brønsted acid sites exhibits excellent performance, and a high furfuryl alcohol conversion of 99.5% and selectivity of 85.2% for 1,5-pentanediol (69.2%) and 1,2-pentanediol (16.0%) could be achieved (hydrogen pressure: 2.5 MPa) at 160 °C. The experimental results and the results obtained using the DFT technique revealed that the high catalytic activity realized during the processes of ring-opening and hydrogenation could be attributed to the synergistic effect between the Cu species and Brønsted acid sites. The Brønsted acid sites on the Si(OH)Al groups significantly affect the ring-opening process of furfuryl alcohol. The methoxy group on furfuryl alcohol adsorbs on the Cu+ sites, and the hydrogenation saturation of the ring-opening intermediate is realized under the influence of the activated hydrogen units on the Cu0 sites. The results reported herein could help promote the continuous production of high value-added pentanediol from biomass-based raw materials in the presence of non-noble metal catalysts. An economical and feasible path for the transformation of biomass resources into high value-added fine chemicals could also be developed.
研究领域:
生物化学
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催化化学
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材料科学
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高影响因子
ChemSusChem
·
2024
·
IF 7.5
Shenyu Wang,Junjie Zhang,Ying Zhang
Graphical The CoO@Co core-shell catalyst, 7Co-0.2Fe/CeO 2 , efficiently catalyzes the hydrogenation and ring-opening of furfural to 1,5-pentanediol, with a high productivity of 54.76 mmol/g Co /h, representing the top activity level among the reported catalysts. The addition of Fe optimizes the Co 2+ /Co 0 ratio, improves substrate adsorption, and prevents the formation of tetrahydrofurfuryl alcohol, a saturated furan byproduct. In the conversion of furfural using non-noble metal catalysts, preferential cleavage of the C2−O bond followed by hydrogenation of the C=C bond facilitates selective access to valuable 1,5-pentanediol (1,5-PeD). Herein, we developed CeO₂ loaded core-shell CoO@Co nanoparticle catalysts. Adjusting Co loading, Fe doping, and reduction temperature improved reaction efficiency. 7Co-0.2Fe/CeO₂ catalysts reduced at 500 °C demonstrated optimal performance. 1,5-PeD produced at 54.76 mmol/g Co /h, representing the top activity levels among the reported catalysts. H₂-TPR, XRD, HAADF-STEM, FT-IR, XPS, and XANES were employed to investigate the catalyst structure-activity relationship. Co 2+ cleaves furan ring C−O bond, Co⁰ promotes double-bond hydrogenation. The CoO@Co structure favors the desired 1,5-PeD production route. Trace Fe species optimize the Co 2+ /Co⁰ ratio, enhance the substrate adsorption, and inhibit the furan ring saturation. These findings emphasize the importance of fine-tuning catalyst structure and composition for selectivity improvement.
研究领域:
化学工程
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催化科学
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可再生资源转化
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DOI
PubMed
高影响因子
Soft Matter
·
2023
·Vol. 19
·期 40
·7775-7780
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IF 3.4
Xin Li,Yuebo Jin,Ying Li,Hongyan Miao,Haijun Wang,Gang Shi
Temperature-responsive spiropyran-functionalized polymers usually require a thermo-sensitive polymer. However, their temperature response range is limited by the lower critical solution temperature (LCST) of the thermo-sensitive polymer, which does not exceed 37 °C. In this work, a hydrophilic polymer (PHEA-SP) sheet was prepared by photo-initiated copolymerization of hydroxyethyl acrylate (HEA) and a spiropyran crosslinking agent (SP). In water, swelling and hydrogen bonding can increase the ring-opening isomerization probability of spiropyran at the PHEA-SP crosslinking point, thus amplifying the discoloration of spiropyran induced by temperature change. PHEA-SP is very responsive to water temperature in the range of 25–55 °C, due to the amplification of spiropyranoid discoloration described above. This method avoids the dependence of the temperature responsive spiropyran-functionalized polymer on a thermo-sensitive polymer and additional UV light, while increasing the upper limit of the water temperature response to 55 °C. In addition, PHEA-SP also shows responsivity to water content in ethanol solution from 0.3% to 100%.
研究领域:
材料科学
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化学
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DOI
PubMed
高影响因子
CATALYSIS LETTERS
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2022
·Vol. 153
·期 7
·2107-2114
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IF 2.936
Zhao Wenli,Niu Xiaopo,Liu Guangni,Zhang Xiurong,Wang Qingfa
Three kinds of Pt nanocrystals with different morphologies (5 nm cubes, 10 nm cubes and 5 nm truncated octahedrons) were synthesized and employed to fabricate Pt/CNT-USY catalysts for selective ring opening of decalin. The 5 nm truncated octahedral Pt/CNT-USY with exposed (100) and (111) facets exhibited higher yield of ring-opening products (53.9 wt%) than the CNT-USY-supported 5 nm cubic Pt catalyst enclosed by the (100) facets (39.6 wt%). Moreover, the 5 nm cubic Pt showed better catalytic activities compared to the 10 nm cubic Pt/CNT-UST catalyst, which ascribed to the smaller size of Pt NCs enriched more revealable metal active sites. DFT calculations demonstrated that the adsorption of decalin on Pt (111) was stronger than that on Pt (100) facets, which was profitable for the selective ring-opening reaction. Graphical Abstract
研究领域:
催化化学
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材料科学
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理论计算化学
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DOI
高影响因子
WATER RESEARCH
·
2017
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IF 6.942
Xing Ding,Shengyao Wang,Wanqiu Shen,Yi Mu,Li Wang,Hao Chen,Lizhi Zhang
In this study, an electrochemical/electro-Fenton oxidation (EC/EF) system was designed to degrade atrazine, by utilizing boron-doped diamond (BDD) and Fe@Fe 2 O 3 core-shell nanowires loaded active carbon fiber (Fe@Fe 2 O 3 /ACF) as the anode and the cathode, respectively. This EC/EF system exhibited much higher degradation rate, decholorination and mineralization efficiency of atrazine than the electrochemical (EC) and electrochemical/traditional electro-Fenton (EC/TEF) oxidation counterpart systems without Fe@Fe 2 O 3 core-shell nanowires. Active species trapping experiment revealed that Fe@Fe 2 O 3 could activate molecular oxygen to produce more OH through Fenton reaction, which favored the atrazine degradation. High performance liquid chromatography , high performance liquid chromatography-mass spectrometry and gas chromatography-mass spectrometry were applied to probe the decomposition and mineralization of atrazine during this novel EC/EF process, which revealed that two intermediates of triazinons (the isomerization of hydroxylated atrazine) were generated during the electrochemical/electro-Fenton oxidation of atrazine in the presence of Fe@Fe 2 O 3 core-shell nanowires. The experimental and theoretical calculation results suggested that atrazine might be degraded via a triazinon ring opening mechanism, while the presence of Fe@Fe 2 O 3 notably accelerated the decholorination process, and produced more hydroxylated products to promote the generation of trazinons and the subsequent ring cleavage as well as the final complete mineralization. This work provides a deep insight into the triazine ring opening mechanism and the design of efficient electrochemical advanced oxidation technologies (EAOTs) for persistent organic pollutant removal .
研究领域:
环境科学
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化学工程
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DOI
PubMed
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
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2023
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IF 11.4
Xifen Zhu,Yuanyuan Yu,Weikun Meng,Jiahui Huang,Guanyong Su,Yin Zhong,Xiaolong Yu,Jianteng Sun,Ling Jin,Ping’an Peng,Lizhong Zhu
Fluorinated liquid crystal monomers (FLCMs) have been suggested as emerging contaminants, raising global concern due to their frequent occurrence, potential toxic effects, and endurance capacity in the environment. However, the environmental fate of the FLCMs remains unknown. To fill this knowledge gap, we investigated the aerobic microbial transformation mechanisms of an important FLCM, 4-[difluoro(3,4,5-trifluorophenoxy)methyl]-3, 5-difluoro-4′-propylbiphenyl (DTMDPB), using an enrichment culture termed as BG1. Our findings revealed that 67.5 ± 2.1% of the initially added DTMDPB was transformed in 10 days under optimal conditions. A total of 14 microbial transformation products obtained due to a series of reactions (e.g., reductive defluorination, ether bond cleavage, demethylation, oxidative hydroxylation and aromatic ring opening, sulfonation, glucuronidation, O-methylation, and thiolation) were identified. Consortium BG1 harbored essential genes that could transform DTMDPB, such as dehalogenation-related genes [e.g., glutathione S-transferase gene (GST), 2-haloacid dehalogenase gene (2-HAD), nrdB, nuoC, and nuoD]; hydroxylating-related genes hcaC, ubiH, and COQ7; aromatic ring opening-related genes ligB and catE; and methyltransferase genes ubiE and ubiG. Two DTMDPB-degrading strains were isolated, which are affiliated with the genus Sphingopyxis and Agromyces. This study provides a novel insight into the microbial transformation of FLCMs. The findings of this study have important implications for the development of bioremediation strategies aimed at addressing sites contaminated with FLCMs.
研究领域:
环境科学
·
微生物学
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DOI
PubMed
高影响因子
Environmental Technology & Innovation
·
2021
·
IF 5.263
Yuying Zhu,Baoqiang Chang,Xue Sun,Haijian Luo,Wenhui Wang,Chaolin Li
The presence of venlafaxine, one of the popular antidepressants, in environmental aquatic media has become a rising issue and potential threat to global ecology and human health. However, advanced technologies for efficient venlafaxine degradation remain underdeveloped. Herein, we propose to use chloride-mediated electrochemical degradation to efficiently remove venlafaxine in aqueous media. The degradation rate of venlafaxine can be significantly increased when Cl − is added to the conventional electrochemical degradation process. It is found the Cl − can convert to Cl ⋅ , which selectively attacks benzene ring and accelerates its opening, thus leading to the improved degradation and mineralization performance of venlafaxine. Based on the analysis of reactive species and degradation intermediates, the degradation pathways with and without Cl − were proposed. Toxicity test demonstrates that the toxic oxidation products formed during venlafaxine degradation could be completely mineralized in the chloride-mediated electrochemical degradation process. This work demonstrates the chloride-mediated advanced oxidation technology may be a promising way to degrade venlafaxine, which may also apply to other emerging antidepressants contained benzene ring, thus paving a new route for the removal of organic pollutants.
研究领域:
环境科学
·
药理学
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化学工程
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DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2019
·
IF 7.015
Haifeng Ji,Hao Xu,Lunqiang Jin,Xin Song,Chao He,Xiaoling Liu,Lian Xiong,Weifeng Zhao,Changsheng Zhao
Although many methods have been investigated to enhance the anti-fouling and hemocompatility of polymeric membranes , developing simplified and high-efficiency strategies to synthesize low-fouling and hemocompatible membranes for safe blood purification remains a huge challenge. Herein, we proposed a facile and straightforward approach to solve the aforementioned problems. Firstly, poly (glycidyl methacrylate) (PGMA) was incorporated into polyethersulfone (PES) membranes via a combination of an in-situ crosslinking polymerization and the phase inversion method. Then, poly (acrylic acid- co -2-acrylanmido-2- methylpropanesulfonic acid) (PAA-AMPS) was covalently coated onto the PES membrane surfaces via an in-situ ring-opening reaction between the PAA and PGMA by simply immersing the membranes into the PAA-AMPS solution. Compared to pristine PES membrane, the protein adsorption amount of the modified membranes reduced; the flux recovery ratio and the resistance to blood cell and bacteria adhesion significantly increased. In addition, the hemocompatibility of the modified membranes was significantly improved, as indicated by the prolongation of the activated partial thromboplastin time and thrombin time of PES-based membranes by 157% and 584% respectively. The proposed simple and high-efficient strategy in this study might be a powerful tool to fabricate polymeric membranes with various and desired functions.
研究领域:
材料科学
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生物医学工程
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DOI
高影响因子
Journal of Bioresources and Bioproducts
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2020
·
IF 0
Guodong Feng,Yan Ma,Meng Zhang,Puyou Jia,Chengguo Liu,Yonghong Zhou
Waste cooking oil was modified to prepare bio-base plasticizers (a, b and c) with terephthalic acid, adipic acid and benzoic acid by transesterification, epoxidation and ring opening reactions, respectively. The polyvinyl chloride (PVC) films (a/PVC, b/PVC and c/PVC) were prepared using a, b and c as bio-base plasticizers. The epoxidation and ring opening reactions were mainly investigated through GC-MS analysis. The structures of bio-base plasticizers (a, b and c) were confirmed by Fourier transform infrared spectroscopy (FT-IR), 1 H NMR and 13 C NMR. The mechanical properties of a/PVC were as good as those of PVC films with the dioctyl phthalate (DOP) plasticizer. Meanwhile, the elongation at break of c/PVC reached 422%. The glass transition temperature ( T g ) from dynamic mechanical analysis (DMA) was reduced to 30.6˚C, 45.3˚C, 23.6˚C and 40.6˚C, respectively when 40 phr of a, b, c and DOP plasticizer were added. Results of thermogravimetric analysis (TGA) illustrated that the thermal degradation stabilitiy of a/PVC films was better than those of c/PVC and DOP/PVC. The volatility losses of a, b and c were lower than that of the DOP. Bio-base plasticizers a and c exhibited excellent migration resistance in different solutions (distilled water, 50% ethanol (w/w)). The FT-IR of PVC films showed that the downfield shifts of the —CH—Cl groups of the PVC plasticized with a and c were greater than that of b/PVC. The bio-base plasticizers b had a better plasticizing effect at low temperature.
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
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