APPLIED CATALYSIS A-GENERAL
·
2016
·
IF 4.012
Hua Wang,Yingge Guo,Cuirong Chang,Xinli Zhu,Xiao Liu,Jinyu Han,Qingfeng Ge
The number of strong acid sites on a hydrolysis catalyst accessible by the bulky cellulose limits its efficiency in the conversion and utilization of biomass-based resources. In this work, high surface area WZr/SBA-15 catalysts (>400 m 2 /g) were prepared by hydrothermal method and characterized using XRD, N 2 adsorption, TEM, Raman, UV–vis, XPS and FTIR of pyridine adsorption. The results showed that doping a moderate amount of ZrO 2 into the WO 3 /SBA-15 catalyst stabilized the tungstate species in the form of a polytungstate species as a result of the strong ZrO x -WO x interaction as well as increased the surface area of the catalyst. The resulting polytungstate species provided strong Brønsted acid sites for hydrolysis. Consequently, the cellobiose conversion was maximized at 5% ZrO 2 loading, corresponding to a maximized surface area and density of Brønsted acid sites. This catalytic activity is significantly higher than that of a WO 3 /ZrO 2 catalyst prepared using the conventional impregnation method, indicating the importance of mesoporous structure to the dispersion of active species and to the accessibility of the active sites by the bulky reactant. This result indicates that the density of the strong Brønsted acid sites with improved accessibility by the bulky reactant is essential to achieve a high hydrolysis activity.
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
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2020
·
IF 5.162
Xin Wang,Lihong He,Jianrong Huang,Nanjing Zhong
In this study, SBA-15 was modified by halogen & haloalkanes and later used to immobilize lipases. The hydrolysis activity and the glycerolysis performance of the immobilized lipases was carefully studied. Highest activity of the immobilized Candida antarctica lipase B (CALB), Lipase from Aspergillus oryzae (AOL), Lecitase® Ultra (LU) and lipase from Rhizomucor miehei (RML) was respectively at 5577, 12000, 2822 and 11,577 U/g; in addition, the highest activity was obtained from the lowest or moderate lipase loading, at 25.73, 90.72, 89.52 and 30.56 mg/g respectively. The mechanism of lipase immobilization was studied and it was through interfacial activation. The halogen & haloalkanes modification of SBA-15 afforded considerable glycerolysis activity for diacylglycerols (DAG) preparation. CALB@SBA-15-CH 2 CH 2 (CF 2 ) 5 CF 3 and CALB@SBA-15-CH 2 CH 2 (CF 2 ) 7 CF 3 were suitable for DAG production, they both exhibited good reusability in glycerolysis reaction, with 117.36% and 93.06% of their initial glycerolysis activity retained respectively after ten cycles of reuse. The relationships between temperature with triacylglycerols (TAG) conversion were ln V 0 = 3.13–3.07/T and ln V 0 = 7.90–4.64/T respectively for CALB@SBA-15-CH 2 CH 2 (CF 2 ) 5 CF 3 and CALB@SBA-15-CH 2 CH 2 (CF 2 ) 7 CF 3 ; in addition, their activation energy ( Ea ) was respectively at 25.50 and 38.54 kJ/mol.
研究领域:
生物化学
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酶工程
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材料科学
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DOI
PubMed
高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
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2015
·
IF 3.453
Hui-Min Zhao,Chang-Miao Di,Lan Wang,Yuan Chun,Qin-Hua Xu
Mesoporous graphitic C 3 N 4 has been synthesized using a novel cross-linked bimodal mesoporous (CLBM) SBA-15 as a hard template. This cross-linked bimodal mesoporous SBA-15 template was prepared by adjusting the pH to alter the copolymer micelle size. The resulting mesoporous g -C 3 N 4 replicates the morphology of the mesoporous silica template, and numerous pore openings are formed on the surfaces. The mesoporous g -C 3 N 4 exhibits a high specific surface area and a large pore volume . The photocatalytic degradation activity of methyl orange on mesoporous g -C 3 N 4 is nearly 15.3 times as high as that on bulk- g -C 3 N 4 under visible light irradiation. The high photocatalytic performance of this sample is due to the high specific surface area and more readily accessible active sites.
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
Catalysis Science & Technology
·
2017
·Vol. 7
·期 23
·5540-5549
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IF 5.773
Xinqiang Feng,Chun Shen,Kaiyue Ji,Jiabin Yin,Tianwei Tan
Mesoporous solid acid catalyst WO3/SBA-15 exhibited high performance for the production of bio-based p-xylene (PX). After immobilization on SBA-15, isolated [WO4]2− tetrahedral species which were coordinatively unsaturated, were generated and functioned as Lewis acid centers. The ratio of Lewis to Brønsted acid sites varied in the range of 7.4 to 13.4 by adjusting the calcination temperature. A high ratio of Lewis to Brønsted acid sites and the mesoporous structure contributed to the high activity and stability: a selectivity of 88.0% for PX with a conversion of 64.4% and a carbon balance of 90.1% was achieved over 0.20-WO3/SBA-15-700. Compared with microporous Sn-Beta, the as-prepared catalyst showed better resistance to carbon deposition with a 20% higher yield. The spent catalyst could be easily regenerated by calcination at high temperature. The conversion decreased by 3% and no loss in PX selectivity was observed after five regeneration cycles. The as-prepared WO3/SBA-15 catalyst is highly active, stable and recyclable, and has high potential towards bio-based PX production.
研究领域:
化学工程
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催化科学
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绿色化学
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DOI
高影响因子
Journal of Oleo Science
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2020
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IF 1.304
Maomao Kou,Siting Feng,Nanjing Zhong
In this study, Lecitase® Ultra (LU) was immobilized onto the parent and the amino-functionalized SBA-15. The immobilization conditions were studied and the activity of the parent SBA-15 supported LU (SBA-15-LU) was found to be at 2177.78 ± 101.84 U/g. After 3-aminopropyl and n-(2-aminoethyl)-3-aminopropyl groups functionalization, enzymatic activity was increased to 3555.56 ± 200.21 and 3444.44 ± 346.41 U/g respectively. The immobilized LU samples were then used to catalyze glycerolysis. The possibility for diacylglycerols (DAG) and monoacylglycerols (MAG) production was evaluated and it was found only suitable for DAG production. In addition, the glycerolysis activity of the immobilized LU was impaired by the tert-pentanol and solvent-free was found suitable. Similar DAG content over 50 wt% could be obtained from glycerolysis by the three immobilized LU samples. The reusability in glycerolysis was evaluated, and 9.79 % of the initial glycerolysis activity was remained from the SBA-15-LU after 5 cycles of reuse. Encouragingly, after 3-aminopropyl and n-(2-aminoethyl)-3-aminopropyl groups functionalization, 62.93 and 83.91% of their initial activity was respectively remained after 5 cycles of reuse.
研究领域:
生物化学
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酶工程
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食品科学
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DOI
PubMed
高影响因子
International Journal of Environmental Science and Technology
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2021
·Vol. 19
·期 8
·7205-7216
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IF 2.86
Wu Chunlai,Liu Qiong,Peng Chuanyun,Xu Wenwen
In this work, novel glutamic acid-functionalized SBA-15 was prepared for sensitive and selective lead and copper ions removal from wastewater sample. The material was characterized by X-ray diffractometry, scanning electron microscope, Brunauer–Emmett–Teller surface area measurement and Fourier transform infrared spectroscopy. The as-prepared material maintains the coordination properties of glutamic acid to lead and copper ions and exhibited better adsorption performance than that of pure SBA-15. The effects of different parameters such as pH of the solution, adsorption time, initial concentration, ion selectivity and regeneration were investigated on the Pb(II) and Cu(II) adsorption by the prepared adsorbent. It was found that the adsorption process can reach equilibrium within 20 min and can be described by pseudo-second-order kinetic model. Adsorption isotherm analysis showed that the adsorption was in accordance with Langmuir adsorption isotherm model, and the maximum adsorption capacity of lead and copper ions was 12.14 mg/g and 13.29 mg/g, respectively. In addition, common co-existed ions have no interference on Pb(II) and Cu(II) adsorption. Moreover, adsorption–elution cyclic results demonstrated that Pb(II)- and Cu(II)-adsorbed composite adsorbent could be effectively regenerated by 0.5 mol/L of HCl, and the regenerated adsorbent could be employed for repeated use without significant deterioration in its real performances, demonstrating the good stability of the adsorbents. Therefore, the composite adsorbent can be used potentially to remove Pb(II) and Cu(II) ions from water samples in practical applications for environmental remediation. Graphic abstract Glutamic acid-functionalized SBA-15 can be used as adsorbent for efficient adsorption/desorption of Pb(II) and Cu(II) from wastewater.
研究领域:
环境科学
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材料科学
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DOI
高影响因子
CELLULOSE
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2020
·Vol. 27
·期 5
·2737-2756
·
IF 4.21
Shen Zhi,Cai Ning,Xue Yanan,Yu Bo,Wang Jianzhi,Song Hao,Deng Hang,Yu Faquan
Abstract A sustained release of anti-infection drugs is beneficial for the reduction of required dressing change times and the protection of the granulation tissue against further infection. In this work, the strategy of encapsulating mesoporous SBA-15 particles in a permeable cellulose membrane (CM) was used in the preparation of antibacterial cellulose based composite membranes to depot store and deliver drugs with prolonged anti-microbial drug release characteristics. It was found that SBA-15 with the protection of phosphate buffered saline prefilled in SBA-15 mesoporous channel could resist strong alkali environment during composite membranes preparation and its mesoporous structure remained intact, which was verified by SEM, TEM and BET results. The resultant cellulose based composite membrane containing 30 wt% SBA-15 (denoted as P-CM-SBA (30%)) had achieved 3.6 wt% drug loading and demonstrated the sustained release of chloramphenicol for 250 h, which was resulted from SBA-15/cellulose structure-inducing two-stage release behavior. Strong antibacterial activity of P-CM-SBA (30%) against S. aureus and E. coli . could last 144 h. In addition, the tensile strength, water vapor transmission rate and swelling properties of P-CM-SBA (30%) conformed to the primary requirements of wound dressing materials. Therefore, cellulose based composite membrane with 30 wt% SBA-15 particles possesses the potential for the application of wound healing. Graphic abstract
研究领域:
材料科学
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生物医学工程
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药剂学
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DOI
高影响因子
RSC Advances
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2016
·Vol. 6
·期 73
·68695-68704
·
IF 3.289
Yiming Ren,Ruizhu Yang,Lang Shao,Hao Tang,Shaofei Wang,Jianlong Zhao,Jingrong Zhong,Chuipeng Kong
Phosphoramide-modified ordered mesoporous silica (SBA-DEPA) materials were prepared via a two-step process involving: (1) the synthesis of phosphoramide via amidation of phosphoryl chloride with a primary amine and (2) modification of the phosphoramide onto SBA-15. The successful preparation was confirmed by FT-IR and NMR spectroscopy. As indicated by the ICP-AES and XRF analysis results, the phosphoramide group has a grafting ratio as high as 12.5%. The morphological information and N2 adsorption–desorption technique proved the highly ordered structure and large specific area of the material, respectively. An excellent performance for uranium sorption was found with a loading maximum of 311.6 mg g−1, a marked promotion relative to unmodified SBA-15. A strong pH and CO2 dependence suggested that near neutral conditions favored the maximum uranium sorption. To our surprise, the sorption took only 5 min to reach a 90% capacity and 20 min for equilibrium, which is extraordinary when compared to many other sorbent materials. The ionic strength partially influences the sorption, which indicates outer and inner sphere sorption both play parts in the process. A sorption capacity of over 90% of the original indicates the excellent reproducibility of SBA-DEPA. DFT calculations based on cluster models suggested a ‘tri-dentate-like’ structure for the uranyl-surface binding site, which may explain the excellent sorption ability of this material.
研究领域:
环境科学
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材料科学
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DOI
高影响因子
APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY
·
2024
·
IF 3.1
Zhang Hongjun,Li Yichao,Wei Litian,Wang Zhao,Zhang Yinjun
A recombinant esterase, BaCE m , derived from Bacillus aryabhattai and heterologously expressed in Escherichia coli , was successfully immobilized on polyethyleneimine-impregnated mesoporous silica SBA-15. This immobilization utilized glutaraldehyde as a crosslinker. Optimal conditions were established with a PEI/SBA-15 ratio of 25% (w/w), a pH of 7.5, and a glutaraldehyde concentration of 0.5% (w/w), resulting in a loading capacity of 76.4 mg/g, a recovery activity of 43.5%, and a specific activity of 7917 U/g for BaCE m . The immobilized BaCE m demonstrated high enantioselectivity, with an “E” value of 203.92, in the resolution assay of ( R , S )-ethyl indoline-2-carboxylate. Notably, the immobilized enzyme, compared to its free counterpart, exhibited enhanced thermostability, maintaining 95.4% of its activity after 3 h at 30 °C. It also showed significant tolerance to organic solvents, retaining 48.4% and 28.7% residual activity in 10% v/v acetonitrile and acetone, respectively. Moreover, its storage stability was confirmed, with 68.5% residual activity preserved after 30 days at 4 °C. Remarkably, the immobilized BaCE m retained 58.1% of its activity after 10 reuse cycles, underscoring the potential of polyethyleneimine-impregnated mesoporous silica SBA-15 as an effective support for enzyme immobilization, promising for industrial applications. Graphical Abstract
研究领域:
生物化学
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酶工程
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材料科学
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DOI
PubMed
高影响因子
CHINESE CHEMICAL LETTERS
·
2011
·Vol. 22
·期 12
·1497-1500
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IF 0.775
Xiao Zheng Lan,Hai Rong Pei,Chuan Xian Cheng
Phase behavior of binary system of bromobenzene–chlorobenzene (C 6 H 5 Br–C 6 H 5 Cl) confined in SBA-15 and MCM-41 (pore diameter 8 nm, 3.8 nm, respectively) has been investigated by means of differential scanning calorimetry (DSC). Phase diagram of C 6 H 5 Br–C 6 H 5 Cl system confined in SBA-15 is a type of the complete miscible both in liquid and solid state, the same phase behavior as the bulk system. However, the phase diagram comprises only one boundary line, which is shifted down 22–36 K with respect to the bulk system. C 6 H 5 Br, C 6 H 5 Cl or the mixture within nanopores of MCM-41 is nonfreezing. The different phase behavior of the system confined in SBA-15 and MCM-41 is thought mainly due to the relative size of pore to molecule.
研究领域:
物理化学
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材料科学
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纳米科技
·
热力学
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DOI
高影响因子
Inorganic Chemistry Frontiers
·
2019
·Vol. 6
·期 7
·1799-1812
·
IF 5.934
Xiaosong Hu,Chaoyue Zhao,Qingxin Guan,Xin Hu,Wei Li,Jun Chen
The chemical transformation of CO2 not only mitigates CO2 released into the atmosphere but also produces fuels and chemicals with important additional value. The activation of stable CO2 molecules is the key difficulty for the efficient conversion of CO2. Herein, we designed a ternary catalyst containing Cu, ZnO, and CeOx and dispersed them in SBA-15 using incipient wetness impregnation. Interestingly, the catalytic performances were improved greatly when the related active components were dispersed inside and outside the pore channels of SBA-15 using the incipient wetness impregnation method. Methanol and CO were controllably produced on the interface of Cu and metal oxides (ZnO and CeOx) due to the synergistic effects between the three active components. The metal oxides play a more important role in CO2 conversion as well as the product selectivity compared to Cu. CeO2 is more efficient than ZnO in promoting the dispersion of Cu nanoparticles and methanol generation. The suitable pore channels of SBA-15 promote the mass transfer and heat transfer while the high specific surface area is favorable to the dispersion of active components, which will facilitate the production of methanol and CO. After continuous hydrogenation evaluation for 100 h, the catalytic performance of the catalyst was still very stable. This work provides a viable strategy to prepare a supported catalyst with highly dispersed active sites, and the catalyst exhibits an efficient catalytic effect on producing methanol and CO.
研究领域:
化学工程
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催化科学
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产品关联
DOI
高影响因子
RENEWABLE ENERGY
·
2022
·
IF 8.634
Xiaocui Wei,Yanan Liu,Yang Cao,Jin Li,Xianghao Meng,Zhao Zhang,Zhongyi Jiang
The catalytic pyrolysis of biomass is a sustainable approach for biofuel production, contributing to replacing fossil resources with renewable resources . The ZSM-5 zeolite remains an attractive catalyst in the catalytic pyrolysis of biomass, and how to reduce the product diffusion resistance and regulate the surface acidity of ZSM-5 should be explored more deeply. Herein, a hierarchical gallium-modified ZSM-5@SBA-15 catalyst is fabricated through coating a mesoporous layered SBA-15 shell on a hollow ZSM-5 core with gallium modified on the surface, which is effective for increasing hydrocarbon production during the catalytic pyrolysis of biomass process. The synergistic effect of hollowness, mesoporosity, and activity in the hierarchical gallium-modified ZSM-5@SBA-15 catalysts is found to affect the yield and quality of bio-oil. Accordingly, the hierarchical gallium-modified ZSM-5@SBA-15 catalyst with 11 wt% Ga loading exhibits a superior deoxygenation ability, and the relative content of hydrocarbons in bio-oil reach to 49.76 area% which is much higher than that of ZSM-5 (35.30 area%). Furthermore, a possible catalytic pyrolysis mechanism of biomass was also proposed to clarify the potential application of hierarchical gallium-modified ZSM-5@SBA-15 catalysts.
研究领域:
能源科学
·
催化化学
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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）