BULLETIN OF THE KOREAN CHEMICAL SOCIETY
·
2017
·Vol. 38
·期 3
·369-377
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IF 0.602
Fei Shi,Guo Bing Li,Hong Liang Sun,Wang Feng Cai
The dihydric alcohol transesterification of 1,4-butanediol with methyl acetate catalyzed by the ion-exchange resin is researched. The chemical system involves two transesterification reactions in series, with 1,4-butanediol monoacetate as an intermediate product. The effects of the catalyst type, catalyst size, catalyst loading, stirrer speed, the initial reactant ratio, and the reactive temperature have been meticulously studied. The results show that this consecutive transesterification is exothermic and the experimental values of reaction enthalpy are −8.50 and −6.85 kJ/mol, which are in good agreement with the values computed from the standard formation enthalpy. Three kinetic models (PH, LH, and ER) are applied to correlate the experimental data, of which ER model gives the best result with the lowest mean relative error. The activation energies are calculated to be 38.53 and 51.06 kJ/mol by ER model, demonstrating that the overall reaction rates are controlled by the reaction on the catalyst surface.
研究领域:
化学工程
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催化反应
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DOI
高影响因子
Molecular Catalysis
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2018
·
IF 0
Yanan Liang,Kunmei Su,Lei Cao,Zhenhuan Li
Lithium doped TiO 2 were prepared by simple impregnation, which was used as heterogeneous catalysts for the transesterification of DMC with BPA. The characterized results of FTIR, XRD, XPS, SEM, TEM and temperature programmed desorption of CO 2 (CO 2 -TPD) showed that the structure and performance of the catalysts were obviously influenced by the doping amount of Li + and calcining temperature. The optimum catalytic activity was obtained when the molar ratio of Ti/Li reached 6 and the calcination temperature came up to 400 ℃, which was due to Li + reaction with TiO 2 to form surface Ti-O-Li at 400 ℃ (Ti/Li-6-400). When the transesterification of DMC with BPA was carried out at 160–180 ℃ over Ti/Li-6-400, BPA conversion reached 46.67%, and the yields of one-methylcarbonate-ended-BPA (MmC(1)) and two-methylcarbonate-ended-BPA (DmC(1)) achieved 36.36% and 5.97%, respectively, and only 9.3% methylation selectivity was detected. In addition, the possible transesterification mechanism was provided.
研究领域:
化学工程
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材料科学
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DOI
ACS Sustainable Chemistry & Engineering
·
2022
·
IF 9.224
Dan Ding,Zhensheng Shen,Tian Ma,Yabo Sun,Menghan Shi,Tao Lu,Bin Wu,Rafael Luque,Yingqiang Sun
Ionic liquid (IL)-catalyzed in situ transesterification (IST) of wet algae is a promising strategy for energy-efficient biodiesel production owing to the dual roles of ILs as both solvents of the cell wall and catalysts of transesterification, while their variations and interactions within different water contents, which subsequently affect biodiesel production, are still out of knowledge. Accordingly, the variations of fatty acid methyl ester (FAME) yields and cellulose solubilities of [Bmim][HSO4], [Bmim][H2PO4], and [Bmim]2[HPO4] under different water conditions are experimentally and theoretically studied. Results indicate that [Bmim][HSO4], [Bmim][H2PO4], and [Bmim]2[HPO4] are acid, weak alkaline, and strong alkaline catalysts of transesterification of lipid with methanol, respectively. FAME yields of both [Bmim][HSO4]- and [Bmim][H2PO4]-catalyzed reactions increase initially with the addition of 1.5 g of water, while they decrease with the increase of water content because of the consequent decline of the nucleophilic index and electrophilic index of the OH groups of [Bmim][HSO4] and [Bmim][H2PO4], respectively. Analogously, slight decreases of FAME yields of [Bmim]2[HPO4]-catalyzed transesterification are observed within 0.0–3.0 g of water, while a notable decrease is presented when 6.0 g of water is added. Contrary to the variation of catalytic properties, the cellulose solubilities of [Bmim][HSO4], [Bmim][H2PO4], and [Bmim]2[HPO4] all decrease with the addition of 1.5 g of water, as the water molecules occupy the H-bonding sites of [Bmim][HSO4]–cellobiose (clb), while the H-bonding interactions of water–clb and water–[Bmim][H2PO4] formed by shared oxygen atoms are enhanced with the increase of water content, subsequently enhancing the H-bonding interactions of ILs–clb and relative cellulose solubilities. The variations of cellulose solubilities of ILs with the addition of 0.0–6.0 g of water are opposite to those of their catalytic properties. This study indicates that the cellulose solubilities and catalytic properties of [Bmim][HSO4], [Bmim][H2PO4], and [Bmim]2[HPO4] compete with each other under different water conditions, providing a potential strategy to offset the negative effect of water content on IST of wet algae.
研究领域:
生物化学
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可再生能源
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催化化学
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DOI
高影响因子
Coatings
·
2023
·Vol. 13
·期 1
·110
·
IF 3.4
Xixi Yu,Yun Hu,Wen Lei,Chengguo Liu,Yonghong Zhou
Developing environmentally friendly UV-curable polymers with multi-functionality is very significant for sustainable development and environmental protection. In this work, a novel tung-oil-based UV-curable oligomer (TOMAH) was synthesized by Diels–Alder and ring-opening reactions via microwave technology. Subsequently, catalyst-free self-healing UV-curable materials based on a maleate monoester transesterification (MMETER) were developed by co-photopolymerization of TOMAH and hydroxyethyl methacrylate (HEMA). The obtained UV-cured materials possessed a high glass transition temperature (Tg> 81 °C), excellent adhesion (grade 1), and flexibility (2 mm). Particularly, the outstanding photopolymerization activity of the UV-curable resins was proved by UV-curing kinetics. In addition, dynamic transesterifications occurred without an external catalyst at a moderate temperature, resulting in good self-healing properties (with a scratch-repair efficiency of 78.6–93.3%) and shape-memory properties for the obtained UV-cured materials. This work combines the multiple advantages of biomass raw material, microwave synthesis technology, UV-curing method, and multifunctional polymers, thus providing an innovative strategy to fabricate sustainable and intelligent coatings.Keywords:UV-curable coatings;self-healing;tung oil;catalyst-free;microwave technology
研究领域:
材料科学
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环境科学
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DOI
高影响因子
ChemistrySelect
·
2024
·Vol. 9
·期 40
·e202401921
·
IF 1.9
Yafeng Zhang,Ying Liu,Zifeng Yang,Zhendong Pan,Congzhen Qiao
Graphical Alkali ILs were chemical anchored inside of 3D polymeric sphere by the combined method of substitution and post -ionic exchanging for preparing the D polymeric spherically alkali ILs catalysts, which could exhibit excellent catalytic activities for producing dimethyl carbonate (sel. ≥99.5 %) in transesterification. Its’ improved catalysis was attributed to the synergetic properties of porous microstructures behaving the amino cation unites with the anion unites of OH − . A novel type of alkyl amine-based ILs [Et 3 N] + [OH] − (triethylammonium hydroxide) behaving strong alkali property have been chemically immobilized onto the polymeric 3D spheres with mesoporous structures, spherical morphology and more uniformed active species onto them to form alkali ILs supported 3D polymeric catalysts(3DPs-ILsOH), which was synthesized via a combined method of substitution with its subsequent anion unites’ exchanging process. The supported 3DPs-ILsOH catalyzed the transesterification of ethylene carbonate (EC) with methanol, which preferred to exhibit the excellent, efficient activities. At milder reaction temperature of 70 °C within 4.0 h, the conversion of EC achieved to 83.3 % with 99.5 % selectivity of dimethyl carbonate (DMC). Under the same reaction conditions, this type of catalysts could be recovered by a simple filtration and was reused eight times without obvious losing catalytic activities and hardly without any leaching of catalytic species. Its’ catalytic process for generating the chemical of DMC from the CO 2 fixation material of EC was studied by using the in-situ FTIR, and was further verified that the synergetic function roles of triethyl amino cations units with OH − anion units onto the supported catalysts might be one of the important reasons for progressing DMC's yields and its’ catalytic efficiency in transesterification reaction.
研究领域:
化学工程
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催化材料
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DOI
高影响因子
FUEL
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2024
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IF 6.7
Sitong Liu,Shengli Niu,Hewei Yu,Kuihua Han,Sunwen Xia,Zihao Yang,Yue Zheng,Yujiao Zhang,Yanan Hao,Abulikemu Abulizi
The current transesterification for biodiesel is normally conducted with heat input and the resource is required to remove the contained water, which is complicated and costly. The novel magnetic catalyst of the bimetallic oxides of CeO 2 and Fe 3 O 4 supported on the hierarchical pore ZSM-5 was prepared and used for the biodiesel production through transesterification of palm oil with methanol under the electrolytic assistance. The prepared catalysts were characterized by SEM-EDS, TEM, FTIR, XRD, CO 2 /NH 3 -TPD, N 2 adsorption–desorption and VSM, etc. The loaded cerium stimulated the particles growth and abundant catalytic active sites were obtained due to the coral-like structure and they were beneficial for transesterification. The presence of both acidic and basic sites guaranteed the strong catalytic capability of the CeO 2 /ZSM-5@Fe 3 O 4 catalyst. Under the optimized transesterification condition of the catalyst dosage of 3 wt%, methanol to oil molar ratio of 18:1, reaction time of 2.5 h, electrolysis voltage of 40 V, presence of 2 % wt/wt of water added and reaction temperature of 25 ℃, the FAME yield of approximately 95 % was achieved. Also, the catalyst showed an acceptable reusability, where the FAME yield of 79 % was obtained after fourth reused cycle. In conclusion, the water in the resource promotes the electrolytic transesterification to occur efficiently at the room temperature.
研究领域:
化学工程
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可再生能源
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催化材料科学
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DOI
高影响因子
Chemical Engineering and Processing-Process Intensification
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2024
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IF 3.8
Sitong Liu,Zhipeng Li,Kuihua Han,Yongzheng Wang,Shengli Niu,Jisen Liu,Jie Zhu,Yue Zheng
The basic active sites are rendered inactive by the free fatty acids (FFAs) in the feedstock. The aim of this study was to maximize the use of cheap and readily available waste cooking oil (WCO) and Sr-Zn oxide catalyst (prepared by sol-gel method) for biodiesel production. The best performing catalyst with a molar ratio of ZnO to SrO of 0.6 gave a biodiesel yield of 91.99 % even with the addition of 11 wt.% oleic acid. The morphology, crystal size and acid-base value of the Sr-Zn oxide catalysts were determined using various characterization methods. The results showed that the total basicity and acidity of the Sr-Zn oxide catalysts was 0.402 mmol/g and 0.367 mmol/g, respectively. After Zn doping, the specific surface area increased from 0.28 m 2 g −1 to 0.41 m 2 g −1 . The adsorption energy of acetic acid on the surface of Sr-Zn oxide was calculated to be the maximum of -268.9 kJ/mol based on the density functional theory. Zinc doping stimulated the C = O bond of acetic acid with the charges of 0.028 e. As a result, Sr-Zn oxide catalysts demonstrated acceptable activity and reusability, indicating bright futures for the heterogeneous catalyst-mediated manufacturing of biodiesel.
研究领域:
生物化学
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催化化学
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可再生能源
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DOI
高影响因子
FUEL
·
2024
·
IF 6.7
Hongbin Xia,Yuxin Wang,Rui Xia,Xinyang Xiong,Guangwen Xu,Jinggang Zhao,Jun Zhou,Lei Shi
An acetate-functionalized heterogeneous catalyst, N + -(Ac), was successfully synthesized via directed substitution of an inert site in quaternary ammonium resin by a weak-base active center and applied to the transesterification of dimethyl oxalate (DMO) with ethanol to prepare diethyl oxalate (DEO). When the optimal N + -(Ac) catalyst catalyzed the DMO transesterification with ethanol for 2 h, the DMO conversion, DEO yield, and corresponding turnover frequency (TOF) reached 93.4%, 49.7%, and 13.04 h −1 , respectively. Additionally, the synthesized N + -(Ac) exhibited catalytic universality for DMO transesterification with different alcohols, and the catalytic efficiency decreased with increasing difficulty of cleaving the hydrogen–oxygen bond from C 2 to C 4 and steric hindrance of isomeric alcohols. The pretreatment experiments of catalyst with different water content and raw materials were designed and the resin matrix, fresh catalyst, deactivated catalyst and regenerated sample were systematically analyzed using various characterization techniques to investigate the catalytic deactivation mechanism of the transesterification reaction between DMO and ethanol to synthesize DEO. The results showed that DMO played a key role in catalyst deactivation and the catalyst was deactivated upon replacement of the active sites by monomethyl oxalate anions from hydrolysis side reaction of DMO. Finally, an efficient raw material regeneration strategy for the catalyst was proposed. Herein, new theoretical support is introduced for the structural evolution of weak-base catalysts and will aid in developing heterogeneous catalysts for oxalate transesterification.
研究领域:
化学工程
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催化科学
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高影响因子
Nanomaterials
·
2022
·Vol. 12
·期 12
·1972
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IF 5.719
Yihao Li,Hepan Zhao,Wei Xue,Fang Li,Zhimiao Wang
A series of Mg-Zr composite oxide catalysts prepared by the hydrothermal process were used for the transesterification of glycerol (GL) with dimethyl carbonate (DMC) to produce glycerol carbonate (GC). The effects of the preparation method (co-precipitation, hydrothermal process) and Mg/Zr ratio on the catalytic performance were systematically investigated, and the deactivation of the catalyst was also explored. The Mg-Zr composite oxide catalysts were characterized by XRD, TEM, TPD, N2adsorption-desorption, and XPS. The characterization results showed that compared with the co-precipitation process, the catalyst prepared by the hydrothermal process has a larger specific surface area, smaller grain size, and higher dispersion. Mg1Zr2-HT catalyst calcined at 600 °C in a nitrogen atmosphere exhibited the best catalytic performance. Under the conditions of reaction time of 90 min, reaction temperature of 90 °C, catalyst dosage of 3 wt% of GL, and GL/DMC molar ratio of 1/5, the GL conversion was 99% with 96.1% GC selectivity, and the yield of GC was 74.5% when it was reused for the fourth time.Keywords:glycerol carbonate;transesterification;hydrothermal process;Mg-Zr oxides
研究领域:
化学工程
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催化材料科学
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DOI
PubMed
高影响因子
Journal of Oleo Science
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2023
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IF 1.5
Siyuan Zou,Hao Zhang,Jianli Wang
Recently, Pickering interfacial catalyst (PIC) was widely applied for liquid-liquid reactions, in view of not only intensifying the mass transfer through significant reducing both the drop sizes and the diffusion distance, but also supplying a flexible platform for the immobilization of valuable active sites. However, the restriction of the mobility of catalyst somehow decreases the activity of a catalyst. To obtain a promise reaction efficiency, we firstly report a synergistic method to enhance the biphasic reaction by Pickering emulsion and ultrasound concepts, targeted at efficient production of biodiesel. Response surface methodology based on Box-Behnken design was applied to optimize the reaction conditions, such as composition of catalyst, reaction temperature, ultrasound power, methanol to oil molar ratio and catalyst amount. An over 98% yield of biodiesel could be achieved within 2.5 hours by ultrasound assisted Pickering interfacial catalysis, which is over two times higher than that of ultrasound assisted homogeneous transesterification system. Besides, the ultrasound assisted Pickering emulsion shortened the reaction time by 3.6 fold when compared to mechanical stirring assisted Pickering emulsion system.
研究领域:
化学工程
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可再生能源
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催化科学
✓ 已验证
DOI
PubMed
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2026
·Vol. 65
·期 31
·16523-16533
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IF 3.9
Tian Xin,Liu Wen,Peng Wenchao,Li Chunli,Liu Jiapeng
The green chemical dimethyl carbonate has become indispensable
in multiple industries and is commonly produced by transesterification.
Heterogeneous catalysts have received considerable research attention
owing to their recyclability and environmental benefits. This work
reports a series of Na-doped C 3 N 4 catalysts
with adjustable acid−base sites. The synergistic effect between
acid−base sites significantly enhances methanol adsorption
and dissociation, thereby promoting dimethyl carbonate formation.
Theoretical calculations reveal charge redistribution in 0.15Na-CN,
and the calculated adsorption energy and bond dissociation energy
confirm that the synergistic effect accounts for enhanced methanol
activation. In situ characterization confirms the adsorption and activation
of reactants on the catalyst surfaces. The 0.15Na-CN catalyst achieves
a dimethyl carbonate yield of 89.94% and a selectivity of 99.56% at
80 ° C after 4 h of reaction, with a turnover frequency of 37.37
h −1 . Moreover, 0.15Na-CN demonstrates excellent
catalytic stability. This work provides an approach for the synergistic
catalytic synthesis of dimethyl carbonate.
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DOI
高影响因子
Applied Food Research
·
2025
·
IF 6.2
Hira Ijaz,Shangde Sun,Gholamreza Abdi,Rana Muhammad Aadil
The objective of the present study was to produce one novel low-calorie structured lipids (SLs), that can be used as a healthy alternative of shortening fat. SLs were produced by the interesterification of tiger nut oil (TNO) and methyl behenate using Lipozyme RMIM at a temperature of 85 °C, an agitation speed of 300 rpm, and a reaction time of 1.25 hours. Resulting SLs characterized through a comprehensive set of advanced physicochemical analysis including AV, slip melting point, solid fat content, total fatty acid composition, x-ray diffraction, differential scanning calorimetry, and triacylglycerol composition were analyzed for both SLs and formulated blends. Results showed that novel SLs had high melting point and solid fat content, to further optimize functionality, unique blend formulations of SLs and TNO were prepared, and the best ratio was selected. This blend demonstrated reduced slip melting point and solid fat content than SLs, suggesting its potential for developing low-calorie, health-friendly shortening fats.
研究领域:
食品科学
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生物化学
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）