EUROPEAN JOURNAL OF INORGANIC CHEMISTRY
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2018
·Vol. 2018
·期 41
·4579-4585
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IF 2.507
Xiao Liu,Wei Qi,Yuefei Wang,Rongxin Su,Zhimin He
Graphical We demonstrated that UiO-66 and its derivatives possess efficiently intrinsic lipase-like activity, catalyzing ester hydrolysis, transesterification and even the esterification reaction. It's –NH 2 functionalized analogue UiO-66(NH 2 ) exhibited the highest catalytic activity due to the synergistic catalytic effect. To overcome the disadvantages of natural enzymes, artificial enzyme mimics attracted increasing attention of researchers. Metal-organic frameworks (MOFs) are expected as one of the most appropriate candidates for artificial enzyme mimics. In this work, we demonstrate that the zirconium-based MOF material UiO-66 and its analogues possess intrinsic lipase-like activity and can efficiently catalyze ester hydrolysis, transesterification and esterification reactions. Furthermore, the UiO-66(NH 2 ) exhibits much higher catalytic activity than that of UiO-66, which can be attributed to the synergy effect between the zirconium cluster centres and the amino moieties during the catalytic cycle.
研究领域:
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
FUEL
·
2025
·
IF 7.5
Tao Wang,Xiqing Wang,Tianshu Liu,Yujie Fu
Realizing high catalytic efficiency and stability always be the core guiding principle and continuous optimization in industrial production. Fatty Acid Methyl Esters (FAMEs) are a key component of biodiesel, serving as a renewable, environmentally friendly alternative to conventional petroleum-based diesel fuel. In this study, a series of novel Brønsted acidic cellulose-based ionic liquids (PCM-ILs) were successfully prepared using cellulose as the raw material through chemical grafting and ionic bonding. These PCM-ILs were first applied to catalyze the transesterification of Pistacia chinensis Bunge seed oil for FAMEs production. PCM-ILs can be tailored by varying anions. Under optimal conditions—methanol/oil ratio (10:1), catalyst (10 wt%), temperature (80 °C), and time (6 h)—the FAME yield reached 98.6 %. In addition, the conversion yield remained above 85 % after the prepared catalyst be recycled for six times. Thus, the development of this straightforward and economically viable cellulose-based assembly opens up innovative avenues for the design of high-performance biocatalysts suitable for industrial applications.
研究领域:
化学工程
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可再生资源技术
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绿色化学
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产品关联
DOI
高影响因子
JOURNAL OF NANOPARTICLE RESEARCH
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2017
·Vol. 19
·期 8
·1-11
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IF 2.02
Cheong Ling-Zhi,Wei Yayu,Wang Hongbin,Wang Zhiying,Su Xiurong,Shen Cai
Zeolitic imidazolate frameworks (ZIF) represent one of the metal organic frameworks (MOF) with high potential for enzyme immobilization due to their exceptional chemical and thermal stability, negligible cytotoxicity, and easy synthesis under mild biocompatible conditions. Amine-functionalized ZIF-8 (An-ZIF-8) are capable of forming multipoint attachment via hydrogen bonding with lipase which will immobilize and further enhance stabilization of lipase. In addition, increased hydrophilicity of An-ZIF-8 will increase partitioning of An-ZIF-8 immobilized lipase at the aqueous/organic interface which enable lipase to expose its active site and retain its catalytic activity at its highest. Present study reports the use of ZIF-8 and An-ZIF-8 nanoparticles as carrier for Burkholderia cepacia lipase (BCL), compares the ester hydrolysis and transesterification activities of immobilized lipase with those of free lipase, and evaluates the reusability and recovery rate of the immobilized lipase. An-ZIF-8 nanoparticles (average 130.42 ± 0.55 nm) were facilely synthesized via mixing ZIF-8 nanoparticles with ammonia hydroxide solution. Despite having similar characteristics of high crystallinity and forming cuboid-like particles, An-ZIF-8 demonstrated significantly ( P < 0.05) lower Brunauer-Emmett-Teller (BET) surface area and higher thermal stability than ZIF-8. BCL were successfully immobilized on ZIF-8 (BCL@ZIF-8) and An-ZIF-8 (BCL@An-ZIF-8) nanoparticles with an average lipase loading rate of ~ 8 mg/g MOF. The immobilized BCL demonstrated no significant differences in terms of esters hydrolysis and transesterification activities with those of free BCL. BCL@An-ZIF-8 demonstrated superior catalytic stability in comparison to BCL@ZIF-8 with retainment of more than 80% of its initial hydrolysis and transesterification activity for at least 10 repeated runs. In addition, more than 80% of the BCL@An-ZIF-8 can be easily recovered during each cycle of the reusability test through simple centrifugation.
研究领域:
生物化学
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材料科学
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酶工程
✓ 已验证
产品关联
DOI
高影响因子
Polymer Chemistry
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2020
·Vol. 11
·期 34
·5512-5525
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IF 5.342
Ming Zhang,Yifei Tu,Zibo Zhou,Guozhang Wu
The exo-hydroxyl group (exo-OH) on isosorbide (ISB) has long been asserted as a highly reactive moiety compared with the endo-hydroxyl group (endo-OH). In this study, calculations based on density functional theory and experiments without adding catalysts reveal that endo-OH has strong nucleophilic ability, and in the case of transesterification with diphenyl carbonate, the nucleophilic attack surmounts steric hindrance in rendering endo-OH more reactive than exo-OH. The kinetics of transesterification with different catalysts is investigated to determine the catalytic reactivity and molecular structure evolution. The results show that preferential activation of exo-OH moieties can be achieved either by reducing the coordination ability of catalytic cations (lg β1) or by enhancing the alkalinity of catalytic anions. Despite the low reactivity of exo-OH on ISB monomers, terminal exo-OH on carbonate oligomers exhibits higher reactivity than terminal endo-OH, justifying the experimental fact that ISB-based polycarbonates (ISB-PCs) are mostly terminated by endo-OH. Balancing the reactivity between endo-OH and exo-OH can be promoted by increasing the reaction temperature, thus accelerating transesterification to a high equilibrium constant. These findings help to clarify the mechanism of ISB transesterification and provide new strategies for the synthesis of high-molecular-weight ISB-PCs.
研究领域:
化学
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材料科学
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DOI
高影响因子
JOURNAL OF THE AMERICAN OIL CHEMISTS SOCIETY
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2018
·Vol. 95
·期 1
·79-88
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IF 1.601
Ting Zheng,Zhenyu Wu,Qinglong Xie,Meizhen Lu,Fan Xia,Guangquan Wang,Yong Nie,Jianbing Ji
Owing to the decrease of global oil price, development of downstream value-added products is important to biodiesel industry. In this study, we used palmitic acid methyl ester (PAME) as a starting material to produce 2-ethylhexyl palmitate (2-EHP), an environmentally friendly biolubricant product, which was derived from the transesterification of fatty acid methyl esters and long chain fatty alcohols. Conventional synthetic routes of 2-EHP have disadvantages, including high catalyst price, low conversion efficiency, and pollution issues. To solve these problems, in situ transesterification of PAME with 2-ethylhexanol (2-EH) was conducted over unsupported potassium carbonate as heterogeneous catalyst. The optimal reaction temperature, 2-EH to PAME molar ratio, and catalyst to PAME mass ratio were 180 °C, 3:1, and 3.0 wt%, respectively. The PAME conversion reached up to 100% within 1 hour under the optimal conditions. In addition, a kinetic model describing the experimental data over a temperature range of 160–180 °C was developed. The dependence of kinetic rate constant ( k ) on temperature was evaluated, and the activation energy ( E a ) for the transesterification of PAME with 2-EH was calculated to be 57.04 kJ mol −1 .
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
JOURNAL OF THE AMERICAN OIL CHEMISTS SOCIETY
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2015
·Vol. 92
·期 4
·495-502
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IF 1.541
Fu Xiao-bo,Chen Jie,Song Xue-li,Zhang Yuan-ming,Zhu Yi,Yang Jun,Zhang Cheng-wu
A novel carbon solid acid catalyst was prepared by incomplete hydrothermal carbonization of β-cyclodextrin into small polycyclic aromatic carbon sheets, followed by the introduction of –SO 3 H groups via sulfonation with sulfuric acid. The physical and chemical properties of the catalyst were characterized in detail. The catalyst simultaneously catalyzed esterification and transesterification reactions to produce biodiesel from high free fatty acid (FFA) containing oils (55.2 %). For the as-prepared catalyst, 90.82 % of the oleic acid was esterified after 8 h, while the total transesterification yield of high FFA containing oils reached 79.98 % after 12 h. By contrast, the obtained catalyst showed comparable activity to biomass (such as sugar, starch, etc.)-based carbon solid acid catalyst while Amberlyst-15 resulted in significantly lower levels of conversion, demonstrating its relatively high catalytic activity for simultaneous esterification and transesterification. Moreover, as the catalyst can be regenerated, it has the potential for use in biodiesel production from oils with a high FFA content.
研究领域:
化学工程
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可再生能源
✓ 已验证
产品关联
DOI
高影响因子
PROCESS BIOCHEMISTRY
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2020
·
IF 2.952
Jian Ou,Xin Yuan,Yu Liu,Panliang Zhang,Weifeng Xu,Kewen Tang
Enzyme immobilization in MOFs offers retained enzyme integrity and activity, enhanced stability, and reduced leaching. In this work, Pseudomonas cepacia lipase (PCL) was successfully immobilized into the Zeolitic imidazolate framework-8 (ZIF-8) by physical adsorption. The amounts of PCL in the immobilized enzyme (PCL@ZIF-8) was determined to be 16.7 % (200.5 mg PCL/g ZIF-8). Furthermore, the immobilized enzyme was applied as efficient bio-catalyst for enantioselective hydrolysis of 2-phenylpropionic acid (2-PPA) ester enantiomers and enantioselective transesterification of 1-phenylethanol enantiomers. The enzymatic activity of the immobilized enzyme was three times more than that of free PCL in enantioselective hydrolysis system, and the enantiomeric excess was maintained above 99 %. There was no significant difference in enzyme activity between immobilized PCL and free PCL in transesterification system. In addition, the immobilized enzyme showed good reusability in both hydrolysis (30.57 % of initial activity, 4 cycle) and transesterification reaction systems (64.38 % of initial activity, 6 cycle).
研究领域:
生物化学
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酶工程
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材料科学
✓ 已验证
DOI
高影响因子
ANALYTICAL BIOCHEMISTRY
·
2018
·
IF 2.275
Jianyong Zheng,Wei Wei,Xing Lan,Yinjun Zhang,Zhao Wang
This study describes a sensitive and fluorescent microplate assay method to detect lipase transesterification activity. Lipase-catalyzed transesterification between butyryl 4-methyl umbelliferone (Bu-4-Mu) and methanol in tert -butanol was selected as the model reaction. The release of 4-methylumbelliferone (4-Mu) in the reaction was determined by detecting the fluorescence intensity at λ ex 330 nm and λ em 390 nm. Several lipases were used to investigate the accuracy and efficiency of the proposed method. Apparent Michaelis constant ( K m) was calculated for transesterification between Bu-4-Mu and methanol by the lipases. The main advantages of the assay method include high sensitivity, inexpensive reagents, and simple detection process.
研究领域:
生物化学
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酶学
✓ 已验证
DOI
PubMed
高影响因子
RENEWABLE ENERGY
·
2018
·
IF 4.9
Ju-Zhao Liu,Qi Cui,Yu-Fei Kang,Yao Meng,Ming-Zhu Gao,Thomas Efferth,Yu-Jie Fu
In this study, Euonymus maackii Seed oil (EMSO) was exploited and evaluated for the first time as a new non-edible oil feedstock for preparation of biodiesel . The EMSO yield was 41.06 ± 2.68 wt%. The fatty acid compositions of EMSO involved palmitoleic acid (2.01%), palmitic acid (14.5%), stearic acid (3.1%), oleic acid (49.8%), linoleic acid (29.3%), 11-Eicosenoic acid (0.1%) and arachidic acid (0.07%). Microwave-assisted transesterification with methanol provided a high conversion yield in short duration under low temperature. The 2.0 wt% of catalyst amount, 10:1 of methanol/oil molar ratio , 40 min of reaction time and 60 °C of temperature were found to be the optimum process conditions for the maximum biodiesel yield of 94.74 ± 2.09%. Using pseudo first-order kinetic model , the reaction rate constants were 2.145 × 10 2 , 3.550 × 10 2 and 6.447 × 10 2 min −1 for 40, 50 and 60 °C, respectively. The thermodynamic property for biodiesel preparation was determined as activation energy = 47.67 kJ/mol. The fuel properties of the biodiesel product were evaluated and comparable to ASTM D-6751 and EN 14214 standards. Overall, this study revealed and confirmed the potential of Euonymus maackii seed oil as the appropriate alternative feedstock for biodiesel production .
研究领域:
能源植物学
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可再生能源研究
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产品关联
DOI
高影响因子
APPLIED CLAY SCIENCE
·
2023
·
IF 5.6
Qiming She,Minyang Qiu,Kejin Li,Jiahui Liu,Chunhui Zhou
Montmorillonite (Mt) as a solid acid catalyst or support has been widely used in catalytic reactions . However, the existence and catalytic activities of its surface basic sites have rarely been revealed. Here, the surface and structure of Na-Mt are modulated by thermal treatment, providing both acidic and basic sites for the transesterification of glycerol with dimethyl carbonate (DMC) to glycerol carbonate (GLC). The experimental results showed that the thermally activated Na-Mt exhibited bifunctional catalytic properties in glycerol transesterification. The Na-Mt calcined at 400 °C had a basic site density of 1.38 mmol/g and led to a glycerol conversion of 96.8% and a GLC yield of 94.5%. Edge surfaces of Na-Mt provided M II (M III ) atoms as Lewis acidic sites for facilitating the generation of glyceroxide anions from activated glycerol and -M-OH groups as Brønsted and Lewis basic sites for enhancing the carbonyl activation of DMC. This work revealed the co-existence of acidic and basic sites over thermally activated Na-Mt for synergetic catalysis in the transesterification of glycerol to GLC, making the development of Mt-based materials as bifunctional catalysts for one-pot acid-base catalytic processes possible.
研究领域:
催化化学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
BIOCHEMICAL ENGINEERING JOURNAL
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2022
·
IF 4.446
Jun Cao,Rong Wu,Feng Zhu,Qihui Dong,Erzheng Su
Non-aqueous biocatalysis has been expanding the application fields of biocatalysis and is playing an increasingly important role in industrial biocatalysis. Deep eutectic solvents (DESs) have been recognized as green reaction media of non-aqueous biocatalysis. To provide guidance for improving the catalytic performance of enzymes in pure DESs, Candida antarctica lipase B (CALB) catalyzed transesterification reaction was chosen as the model reaction to assess the catalytic efficiency in different series of pure DESs. The catalytic efficiency of CALB was strongly influenced by the properties of DESs. Hydrophobic DESs caused less inactivation of CALB than hydrophilic DESs. The highest yield in hydrophobic DESs reached 56.75% after 12 h. The amount of carboxyl group in hydrophobic DESs, the amount of hydroxyl group in hydrophilic DESs, and the length of carbon chain had positive impacts on the catalytic efficiency of CALB in DESs. Learning from the CALB behaviors in DESs, a preliminary attempt in rational design DESs for higher transesterification efficiency was provided. Except for reaction media, the catalytic activity of CALB in DESs was improved by medium engineering means and enzyme engineering measures, such as adding a trace amount of water, imprinting CALB with pH buffer or inorganic salt, and protecting CALB by lyoprotectants. Synergistic effect of multiple activation methods could also be observed in improving the catalytic efficiency. This study can provide insights into expanding the application of DESs in non-aqueous biocatalysis.
研究领域:
生物化学
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绿色化学
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工业生物技术
✓ 已验证
DOI
高影响因子
APPLIED CATALYSIS A-GENERAL
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2016
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IF 4.012
Xianghai Song,Yuanfeng Wu,Fufeng Cai,Donghui Pan,Guomin Xiao
A series of efficient and low-cost Li/ZnO catalysts were prepared by a simple impregnation method and investigated for the synthesis of glycerol carbonate (GC) from the transesterification of glycerol with dimethyl carbonate (DMC). The Li/ZnO catalysts were characterized using XRD, SEM, FT-IR, TG-DSC, TPD and XPS. It was found that the basicity of the catalysts highly depended on the Li loading and calcination temperature. The weak and moderate basic sites on the catalyst surfaces originated from the ZnO and Li + interaction. The strong basic sites were attributed to the substitution of Zn 2+ by Li + in the ZnO lattice, which led to straining of Zn-O bonds and the formation of [Li + O − ] species. It was the strong basic sites rather than the weak and moderate basic sites that catalyzed the transesterification of glycerol with DMC. The highest catalytic activity was observed over the ZnO loaded with 1 wt.% LiNO 3 and calcined at 500 °C. Glycerol conversion of 97.40% and GC yield of 95.84% were obtained over this catalyst at 95 °C in 4 h.
研究领域:
催化化学
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材料科学
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绿色化学
✓ 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）