BIOMASS & BIOENERGY
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2025
·
IF 5.8
Yunfei Liu,Hewei Yu,Xiuxiu Chen,Zekai Sun,Lizeng Peng,Hongyu Si
This study focused on the optimized preparation of biodiesel over a ZrO 2 -modified CaO catalyst. CaO/ZrO 2 catalysts were synthesized by impregnation, co-precipitation, and sol-gel methods, and analyzed by various characterization methods, including N 2 adsorption-desorption, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), thermally programmed desorption of CO 2 (CO 2 -TPD), and scanning electron microscopy (SEM). The CaO/ZrO 2 catalyst synthesized by the impregnation method had a uniform microstructure, good crystallinity, a uniform spherical particle structure with large pores and slits, and a density of surface alkali sites of 1.898 mmol g - 1 . Using the impregnation method, the best synthesis conditions were determined as a calcination temperature of 700 °C and a Ca/Zr molar ratio of 3:2. Furthermore, the optimal reaction conditions were determined by single-factor experiments as a catalyst dosage of 8 wt%, a molar ratio of methanol to oil of 12, a reaction temperature of 64 °C, and a reaction time of 2 h. Under these reaction conditions, the yield of fatty acid methyl esters (FAME) reached 95.9 %, decreasing only marginally to 77.6 % after four reuses of the catalyst. It is hoped that this study may provide important research guidance for developing solid basic catalysts for preparing FAME by transesterification under mild conditions.
研究领域:
催化化学
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可再生能源
·
材料科学
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产品关联
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2024
·
IF 2.7
Linda Yahia Cherif,Nacira Naar,Ahmed Mekki,Amina Ouadah,Rania Ahmed Hamada,Djalal Trache
Polylactic acid (PLA) is a biosourced thermoplastic polymer widely used in various fields such as biomedical, packaging, and prototyping. Enhancing PLA thermal and mechanical properties has been a research focus, by transforming it into a vitrimer, a new polymer class. This study demonstrated the effectiveness of a dual reactive extrusion process followed by vacuum compression molding to improve a thermoplastic's properties with vitrimer tendency, using PLA as the main component, diglycidyl ether bisphenol A (DGEBA) as an additive, and zinc acetate as a catalyst. Several characterizations were carried out to assess the thermal, morphological, and mechanical properties of the developed PLA mixtures. Moreover, a kinetic study using three iterative isoconversional integral models (iterative Kissinger–Akahira–Sunose (it-KAS), iterative Flynn–Wall–Ozawa (it-FWO), and Trache–Abdelaziz–Siwani) was employed to analyze the effects of the catalyst and DGEBA on the cross-linking reaction kinetics after the process employed in this work. Results demonstrated the presence of a cross-linked structure in addition to a promising polymer behavior characterized by enhancements in toughness, ductility, and cross-linking density by 290%, 127.5%, and 80.5%, respectively. Finally, the optimal composition exhibited almost 96% self-healing of its surface, demonstrating significant potential for advanced material applications.
研究领域:
材料科学
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聚合物化学
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生物医学工程
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产品关联
DOI
高影响因子
FOOD CHEMISTRY
·
2024
·
IF 8.5
Chuang Yang,Yufei Zhang,Yuanzhi Xu,Yibin Zhou,Shiyi Li,Mingming Zheng
An applicable and highly efficient methodology for the preparation of medium- and long-chain triglycerides (MLCTs) via the enzymatic transesterification of coconut oil with long-chain fatty acid triglycerides, named camellia oil, olive oil, linseed oil, algal oil, and rapeseed oil, respectively, has been proposed. The novel system achieved equilibrium in 5 min, and the MLCT yield ranged from 78.7 to 83.8 %. This is the fastest record reported to date. The catalytic efficiency of the novel biocatalyst, CSL@HMS-C 8 , was 140 g/g•h, 1.43 times higher compared to the control (free lipase), and it retained 62.5 % of its relative activity after 15 cycles. A UPLC-MS provided an accurate structural analysis of the MLCTs, and molecular docking analysis was performed to understand the binding interactions between the protein and molecules. The method of preparing MLCT enriched with functional fatty acids in this paper is efficient, broadly applicable, economical, and promising for industrial applications.
研究领域:
生物化学
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食品科学
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工业生物技术
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产品关联
DOI
PubMed
高影响因子
POLYMER
·
2024
·
IF 4.1
Chang Su,Jue Cheng,Junying Zhang,Feng Gao
Since its first report in 2011, researches on vitrimer transesterification catalyst systems had been gradually focused on three aspects: low toxicity and low corrosion, good compatibility with resin matrix, and high catalytic performance for bond exchange reactions. However, it is difficult to obtain a catalytic system that can simultaneously meet the above three expectations. This research conducted the preparation of autocatalytic transesterification epoxy vitrimers by directly mixing small tertiary amine molecules with epoxy-anhydride systems and covalent incorporating tertiary amine structures into curing systems. And the influence of tertiary amine structures and covalent incorporation on the various properties of vitrimers was also discussed. A tertiary amine promoter composed of isofunctional group ratio reaction from di-n-hexamine and epoxy resin provided by this research overcame the problem of poor compatibility between tertiary amine and epoxy resin, introduced a highly active catalytic structure into vitrimer curing system. And the result indicated that the vitrimer prepared according to our new strategy had excellent comprehensive performance. In conclusion, a new idea of covalent incorporation was proposed to provide ideas and inspiration for the development of new tertiary amine-based autocatalytic transesterification epoxy vitrimers.
研究领域:
材料科学
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聚合物化学
·
催化
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产品关联
DOI
高影响因子
FUEL
·
2020
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IF 5.578
Hao Sun,Kang Sun,Fei Wang,Yanyan Liu,Linfei Ding,Wei Xu,Yunjuan Sun,Jianchun Jiang
This study reports a one-step facile synthesis of a novel heterogeneous granule base catalyst, dubbed CaO/AC that contains small calcium oxide (CaO) nanoparticles embedded within hierarchical activated carbon (AC). The CaO/AC hybrid exhibited a 98.59 wt% fatty acid methyl esters yield, with 89.75% less catalyst compared to pristine CaO. In addition, the CaO/AC granular catalyst, which was easily recovered without any post-treatment, presented sustainable catalytic activity after two cycles of transesterification. The calcium cations penetrated into the cell wall of coconut shell by vacuum impregnation, and the carbonization of cell wall suppressed the agglomeration of calcium compound, which was essential for the catalytic self-activation of Ca-doped coconut shell. The pyrolysis atmosphere and dwelling time were investigated to demonstrate the dual function of calcium. Owing to the catalytic effect of Ca during the self-activation process, the hierarchical activated carbon with improved mesopores was manufactured. On the other hand, CaO nanoparticles with an average size of 14.7 nm were in-situ encapsulated within the mesopores of hierarchical carbon matrices. The additional formation of mesopores and high dispersion of CaO nanoparticles were responsible for the enhanced inner mass transfer and the number of accessible alkaline sites in transesterification of triglycerides, leading to the high catalytic activity and stability of CaO/AC.
研究领域:
材料科学
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催化化学
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产品关联
DOI
高影响因子
ACS Omega
·
2020
·
IF 2.87
Xiaobing Chen,Zhenhua Li,Yuan Chun,Fan Yang,Haocheng Xu,Xingcai Wu
Many researchers reported that a sigmoid kinetic curve was obtained in oil transesterification with methanol catalyzed by CaO and gave different explanations for this formation. In this paper, heterogeneously catalyzed transesterification of soybean oil with methanol using CaO has been investigated. The solid catalyst and the liquid reaction mixture under different reaction time periods were characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, and high-performance liquid chromatography (HPLC) to reveal the formation of an S-shape kinetic curve. The appearance of calcium hydroxide, calcium methoxide, calcium glyceroxide, fatty acid calcium, diglycerides, and monoglycerides and their contributions to the kinetic curve have been discussed. The low reaction rate in the induction period can be attributed to mass transfer in this three-phase system. However, the formation of surfactants, diglycerides and monoglycerides, promotes the emulsification of the reaction mixture and numerous emulsion reactors are generated. These emulsion reactors can improve the contact of the solid catalyst with the reactants and thus accelerate the reaction.
研究领域:
化学工程
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催化反应
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产品关联
DOI
PubMed
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2022
·
IF 4.326
Fan Zhang,Wujin Ye,Wenjuan Zhou,Xinchen Gao,Huagao Fang,Yunsheng Ding
It is urgently required to achieve good thermal conductivity and electrical insulation performance in polymer-based composites with the minimum incorporation of functional fillers. In this work, the selective distribution of multiwalled carbon nanotubes (MWCNTs) in the segregated network of hexagonal boron nitride (h-BN) in the epoxy vitrimer matrix was achieved by compression molding, in which interfacial welding was enabled by small-molecule-participated dynamic transesterification at elevated temperatures. Due to the synergistic contribution of the well-structured nanofiller network, the epoxy vitrimer composites demonstrate enhanced thermal conductivity and electrical insulation at low filler content. The composite containing 1 wt % of MWCNTs and 8 wt % of h-BN shows thermal conductivity and electrical resistivity of 0.83 W/(m·K) and 1.92 × 1011 Ω·cm, respectively. The electrical resistivity can be further improved by increasing the segregated h-BN content. This method provides a novel way to prepare cost-effective polymer composites with excellent thermal conductivity and electrical insulation.
研究领域:
材料科学
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高分子科学
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复合材料
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产品关联
DOI
高影响因子
FUEL
·
2022
·
IF 8.035
Wenqiang Liu,Yajuan Wang,Juan Zhang,Qingwen Shan
Large particle spherical poly-ionic liquid–solid base catalyst (PILs-FL) was synthesized by suspension polymerization. This catalyst was characterized by SEM-EDS, T.G., FT-IR and BET-BJH. The characterization results show that PILs-FL has a specific core structure, a certain size of surface area (168.7 m 2 /g), pore size(6.3 nm), and high alkalinity (2.6 mmol/g). The catalyst performance was evaluated by vinyl carbonate and methanol reaction to form dimethyl carbonate (DMC). The reaction conditions were optimized in detail. The optimal reaction conditions were that the molar ratio of methanol and ethylene carbonate 9:1, catalyst dosage 3 wt%, reaction time 5 h, and temperature 90 °C, The yield of DMC was up to 93.7% under the optimal reaction conditions. In addition, The catalyst is separated very easily by simple filtration. The catalyst activity hardly decreased after being reused five times, and the catalyst shape was not destroyed, which meant that the catalyst had a high mechanical strength.
研究领域:
化学工程
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催化材料
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产品关联
DOI
高影响因子
APPLIED CATALYSIS A-GENERAL
·
2021
·
IF 5.706
Qian Wang,Meiling Ge,Xuan Guo,Zhijun Li,Agen Huang,Fu Yang,Rong Guo
The mesoporous supports of alkylated poly(ionic liquid)s (PILs) are got through free radical copolymerization . With an immobilization yield of 99% for Candida antarctica lipase B (CalB), the biocatalyst showed high advantage for biodiesel production under mild conditions. Typical catalyst CalB 0.2 @PIL-C8 was capable of effectively converting soybean oil into biodiesel with a yield of 68.2%, which is higher than Novozym 435 for 57.5%. The biodiesel yield was almost 1.5 folds compared to that of free CalB under the same conditions. And the catalyst remained about 80% activity in a seven-run recovery test with no CalB leaching in the whole process. The hydrophobic PILs not only provide a suitable reaction micro-environment but also can help CalB keep an open conformation in immobilizing with its flexible hydrophobic alkyl chains. This research offered a green and effective strategy for regulating the hydrophobicity and surface potential of support to enhance the performance of immobilized lipase.
研究领域:
化学工程
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生物技术
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材料科学
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环境科学
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产品关联
DOI
高影响因子
POLYMER TESTING
·
2023
·
IF 5.1
Hechen Liu,Zhanglin Sun,Liwei Wei,Yunpeng Liu,Songsong Zhou,Qi Ge,Chang Liu,Xinyang Li
Traditional thermosetting epoxy resins are widely applied in many fields due to their excellent performance. However, stable internal crosslinked networks hinder the repair of epoxy resins damaged during the operation and the recycling of decommissioned epoxy resins. Since vitrimers are epoxy resins that exhibit dynamic covalent bonding, reversible repair properties, and recyclability, they offer a potential solution to this problem. Therefore, by introducing an ester-exchange catalyst, we further introduced disulfide (S–S) bonds to the crosslinked network to construct a vitrimer resin exhibiting double-dynamic bonds, systematically investigated the basic thermodynamic and electrical properties of resins containing different S–S bond contents, and studied the self-healing properties of the possible multispecies and multiscale physical and electrical damages during device operation. Moreover, we investigated the self-healing properties of resins containing different S–S bonding contents. Results showed that the resin exhibited excellent electrical insulation, and the dynamic properties of the resin increased with the increasing number of S–S bonds in the crosslinked network, which considerably increased the repair efficiency and damage repair scale. In addition, the excellent dynamic properties rendered the resin degradable, enabling the non-destructive recycling of valuable materials from the resin matrix and specific processable remodelling and endowed the resin with thermally elastic shape memory properties. This work helps expand the class of vitrimer resins and promotes the application of vitrimers for manufacturing environmentally friendly electrical equipment.
研究领域:
材料科学
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高分子化学
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绿色化学
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产品关联
DOI
高影响因子
APPLIED CATALYSIS A-GENERAL
·
2026
·
IF 4.8
Xiaofei Ma,Shijiao Hao,Hui Jiang,Weiqian Qi,Hefang Wang
La 2 O 2 CO 3 -Cu-Al mixed oxides (CL X A-LDO) were fabricated via the calcination of lanthanum carbonate-doped Cu-Al layered double hydroxides (LDHs) with unique wool-scale-like lamellar structures. CL X A-LDO were employed for the synthesis of dimethyl carbonate (DMC) via the transesterification of methanol with propylene carbonate (PC). Characterization via XRD, FT-IR, TG, and SEM confirmed that lanthanum carbonate-doped Cu-Al LDHs with unique wool-scale-like lamellar structures were successfully prepared. After calcination, these precursors transformed into La 2 O 2 CO 3 -CuO-Al 2 O 3 composites. CO 2 -TPD and XPS results indicate that CL 1.0 A-LDO-600 possesses abundant medium/strong basic sites and a favorable O II /O I ratio. Consequently, CL 1.0 A-LDO-600 exhibited a PC conversion of 68.44% and a DMC yield of 67.84% under mild conditions (80 °C, 2 h, catalyst loading 2.0 wt%, methanol/PC molar ratio = 10). Moreover, CL 1.0 A-LDO-600 demonstrated high stability, with only a modest activity loss (Δ PC = 6.2%) after six consecutive cycles. The kinetic analysis indicated a complex reaction mechanism. However, this behavior was effectively simplified to a pseudo-first-order reaction model, providing activation energies of Ea(k + ) = 47.17 kJ·mol -1 (forward) and Ea(k - ) = 44.46 kJ·mol -1 (reverse). The experimental data were systematically validated using a particle swarm optimization-backpropagation artificial neural network (PSO-BP) model. The hybrid model demonstrated superior predictive accuracy, achieving R 2 values of 0.9956 and 0.9916 for the training and testing sets, respectively, thereby outperforming the conventional BP model. This work provides fundamental insights into the rational design of LDHs-derived mixed oxide catalysts for sustainable DMC synthesis.
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产品关联
DOI
高影响因子
Frontiers of Chemical Science and Engineering
·
2025
·Vol. 19
·期 8
·1-11
·
IF 4.5
Zhang Yingqi,Chen Chao,Xie Enxue,Hu Mengping,Fu Guoying,Wang Yan,Li Liang,Yan Xianzai,Zhang Zedong,Wu Guoqiang
Microporous and mesoporous silicalite-1 (S-1) and titanium silicalite-1 (TS-1) zeolite supported molybdenum (Mo) catalysts were synthesized and applied in the transesterification of Jatropha seed oil (JO) to produce biodiesel. Various analytical results have revealed that the MoO 3 species are highly dispersed on their surface without destroying the zeolite framework and pore structure. Compared with the mesoporous 7Mo/mesoporous S-1 and 7Mo/mesoporous TS-1 catalysts, the microporous 7Mo/S-1 and 7Mo/TS-1 catalysts exhibit high Mo species contents and surface acidity, indicating that Mo species can enter the inner surface of mesoporous zeolites. However, the Mo species on the outer surface of catalysts are only activity centers owing to the accessibility between the Mo species and JO. Therefore, compared with the low activity of the S-1 and TS-1 catalysts, the 7Mo/S-1 catalyst exhibited the highest catalytic performance, with a JO conversion of 95.7% and a biodiesel selectivity of 99.9%. Finally, 7Mo/S-1 demonstrated good catalytic stability, regeneration performance and broad substrate versatility, and the fuel properties of the as-synthesized biodiesel conformed to the current international standard. The influence of the pore structure and Mo species on the catalytic activity has been clarified, providing a theoretical and practical foundation for developing efficient heterogeneous catalysts for biodiesel production.
研究领域:
化学工程
·
催化科学
·
可再生能源
·
材料科学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）