CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Chengming Wu,Quan Wang,Jifan Li,Chun-Ling Liu,Wen-Sheng Dong
Catalytic conversion of biomass-derived platform chemicals into bulk chemicals p -xylene (PX) is appealing yet challenging due to low catalytic efficiency and severe reaction conditions. In this work, we fabricated a series of phosphate-modified ZrO 2 /SBA-15 ( x P-Zr/SBA-15) via adjusting the addition of phosphoric acid, and used them for the catalytic conversion biomass-derived 2,5-dimethylfuran (DMF) and ethylene to PX. Because of the enhanced adsorption capability for the reactant molecules (DMF and ethylene) and the good synergistic effect between Brønsted acid sites (P-OH) and Lewis acid sites (Zr 4+ ), 30P-Zr/SBA-15 revealed an excellent catalytic performance in the selective conversion of DMF into PX. The DMF conversion was 98.5%, PX yield was 92.0% at 250 °C for 12 h, and the corresponding PX productivity was upto 50.5 mmol PX ·g cat −1 ·h −1 . The results are far superior to those obtained on most previously reported catalysts in the literature under similar reaction conditions. The kinetic study revealed that 30P-Zr/SBA-15 has a lower apparent activation energy for the tandem reaction including the Diels-Alder reaction (57.0 kJ·mo −1 ) and dehydration reaction (37.7 kJ·mo −1 ). Moreover, the 30P-Zr/SBA-15 catalyst exhibited the excellent recyclability and could be recycled at least six times without a significant loss of activity. On the basis of the temperature-programmed surface reaction of DMF and ethylene, a reasonable reaction mechanism was proposed.
✓ 已验证
产品关联
DOI
高影响因子
BIOPROCESS AND BIOSYSTEMS ENGINEERING
·
2022
·Vol. 45
·期 6
·1075-1088
·
IF 3.434
Wei Kaixin,Wu Xiaomei,Ma Baodi,Li Zhi,Xu Yi
A series of nickel-incorporated SBA-15 mesoporous molecular sieves (Ni-SBA-15) were prepared as support for the immobilization of his-tagged recombinant Microbacterium esterase. The Ni-SBA-15 could strongly and specific absorb the his-tagged esterase from cell disrupted supernatant. It was found that the nickel amount in Ni-SBA-15 has dramatic influence on the activity and thermo-stability of immobilized enzyme, while the kinds of nickel precursor had little effect on enzyme stability. The morphology, chemical composition and structure of the best support NiCl 2 -SBA-15 (Ni-SBA-15 prepared from NiCl 2 precursor) were characterized by various spectroscopy techniques. The immobilized esterase retained full activity of free esterase and showed high immobilized yield (> 90%) with higher thermo-stability, pH stability and organic solvent resistance compared with free enzyme. The optimum reaction temperature increased from 35 to 40 °C and the optimal reaction pH moved from 10.0 to 8.0 after enzyme immobilization. The immobilized esterase exhibited excellent storage stability and keeping 92% of the initial activity after 30 days’ storage at 25 °C. In addition, the immobilized esterase had excellent reusability for the synthesis of key chiral intermediate of d -biotin and the substrate conversion could still keep 100% after 13 cycles continuously. Finally, optical pure (4 S , 5 R )-hemiester was obtained in 80.8% isolated yield and 99% purity in the gram preparative scale.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Applied Materials & Interfaces
·
2021
·
IF 9.229
Zhijun Li,Qinghui Ren,Xuexia Wang,Wenxing Chen,Leipeng Leng,Mingyang Zhang,J. Hugh Horton,Bo Liu,Qian Xu,Wei Wu,Jun Wang
Single-atom catalysts (SACs) have great potential to revolutionize heterogeneous catalysis, enabling fast and direct construction of desired products. Given their notable promise, a general and scalable strategy to access these catalyst systems is highly desirable. Herein, we describe a straightforward and efficient thermal atomization strategy to create atomically dispersed palladium atoms anchored on a nitrogen-doped carbon shell over an SBA-15 support. Their presence was confirmed by spherical aberration correction electron microscopy and extended X-ray absorption fine structure measurement. The nitrogen-containing carbon shells provide atomic diffusion sites for anchoring palladium atoms emitted from palladium nanoparticles. This catalyst showed exceptional efficiency in selective hydrogenation of phenylacetylene and other types of alkynes. Importantly, it showed excellent stability, recyclability, and sintering-resistant ability. This approach can be scaled up with comparable catalytic activity. We anticipate that this work may lay the foundation for rapid access to high-quality SACs that are amenable to large-scale production for industrial applications.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
·
2014
·
IF 3.209
Bing Yan,Qiu-Ping Li
Several kinds of novel lanthanide organic–inorganic mesoporous hybrid luminescent materials have been assembled by introducing the ternary lanthanide ions (Eu 3+ , Tb 3+ ) and beta-diketone (TTA, TAA) into the functionalized mesoporous hosts through the coordination bond and covalent bond by using 3-chloropropyltriethoxysilane modified 1,4,7,10-tetraazacyclododecane (Cyclen-Si) as an organic bridge molecule. These multicomponent hybrids are characterized by FTIR, TEM, XRD, thermogravimetric analysis, diffuse reflectance UV–Vis spectra and nitrogen adsorption–desorption isotherms, especially the photoluminescence properties of them. The luminescent spectra of the hybrids reveal that the MCM-41 based materials show strong emission intensities, high luminescent quantum efficiencies, long luminescent lifetimes and exhibit characteristic red and green luminescence originated from lanthanide ions (Eu 3+ or Tb 3+ ), which suggesting the Cyclen-Si bridge molecule is favorable for the assembly of lanthanide functionalized luminescent hybrids.
✓ 已验证
产品关联
DOI
高影响因子
GREEN CHEMISTRY
·
2024
·Vol. 26
·期 11
·6601-6615
·
IF 9.3
Chao Yuan,Yuan Zhang,Zhiyuan Zong,Shenghui Zhou,Hongyou Cui,Hongzi Tan
Catalytic wet air oxidation (CWAO) is a very promising technology for the elimination of various refractory pollutants, but to activate dioxygen under mild conditions is a great challenge. In this research, we report a series of Cux/CNy@SBA catalysts to activate dioxygen for CWAO of phenols and antibiotics under mild conditions. The catalysts were prepared by in situ growth and dispersion of g-C3N4 and Cu species over the SBA-15 surface. Characterization by HRTEM, EDS, XRD, FT-IR, and XPS showed that the formed ultrathin g-C3N4 coating over the surface of SBA-15 provided abundant locations to embed the Cu species and thus more active sites were generated. UV-vis DRS characterization proved that the synergetic effect between Cu species and the SBA-15-dispersed g-C3N4 greatly enhanced the ability to activate dioxygen. It was found interestingly that superoxide radicals (˙O2−) were the dominating active species at low temperature, while both ˙O2− and hydroxyl radicals (˙OH) became the active species at high temperature during the CWAO of phenol. Among the catalysts tested, Cu1/CN3.3@SBA-N demonstrated the highest activity, affording 100% phenol removal and more than 90% chemical oxygen demand (COD) removal, even at 90 °C and atmospheric dioxygen pressure. Modification of the SBA-15 surface with KH-550 could remarkably improve the recycling stability of the catalyst. These findings provide new insights for the development of highly effective catalysts for the activation of dioxygen, particularly in the field of CWAO wastewater treatment.
✓ 已验证
产品关联
DOI
高影响因子
BioEnergy Research
·
2015
·Vol. 8
·期 3
·1263-1274
·
IF 3.541
Zhang Zhi-bo,Lu Qiang,Ye Xiao-ning,Wang Ti-peng,Wang Xian-hua,Dong Chang-qing
Solid phosphoric acid (SPA) catalysts with different carriers were prepared and used for catalytic fast pyrolysis of poplar wood to produce levoglucosenone (LGO), a valuable anhydrosugar derivative that can be used in various organic synthesis applications. Pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) experiments were performed to evaluate the catalytic capabilities of these catalysts under different reaction conditions. The results indicated that SPA catalyst prepared with the SBA-15 carrier exhibited the best catalytic capability for selectively producing LGO. Both the catalytic pyrolysis temperature and catalyst-to-biomass ratio affected the pyrolytic products greatly. The maximal LGO yield reached as high as 8.2 wt% from poplar wood, obtained at the pyrolysis temperature of 300 °C and the catalyst-to-biomass ratio of 1. The by-products during the catalytic pyrolysis process were mainly acetic acid (AA) and furfural (FF). In addition, the SPA catalyst possessed better catalytic capability than the liquid phosphoric acid (H 3 PO 4 ) catalyst to produce LGO.
研究领域:
生物能源
·
催化化学
·
生物质转化
·
热解化学
·
绿色化学
·
可再生资源利用
✓ 已验证
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2021
·Vol. 45
·期 14
·6192-6205
·
IF 3.591
Haiqing Xu,Yuhang Gao,Qiantu Tao,Aiping Li,Zhanchao Liu,Yinhua Jiang,Hongwei Liu,Rongguang Yang,Yan Liu
A novel salicylic acid (SA) molecularly imprinted polymer (MIP) has been synthesized successfully by a surface imprinting technique based on the SBA-15 nanoreactor. SBA-15, selected as the nanoreactor for immobilizing the monomers and template molecules, would be an option to develop a new SA imprinting strategy. The obtained imprinted materials were characterized by Fourier transmission infrared spectrometry (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and nitrogen adsorption–desorption isotherms. The results suggested that MIP possessed an excellent ordered hexagonal mesoporous structure, which preserved the highly ordered mesoporous structure of SBA-15. Experimental variables influencing the adsorption process, including the initial pH, initial concentration and temperature, were optimized by the three-level Box–Behnken experimental design with the three factors combining the response surface method (RSM) for the first time. The optimal adsorption conditions were obtained to achieve the maximum adsorption capacity of SA as follows: initial solution pH 4.62, initial SA concentration 52.38 mg L−1, and temperature 35.0 °C. Under these conditions, the experimental value of the adsorption capacity was 44.435 mg g−1, which was very close to the predicted value (43.429 mg g−1). Furthermore, the adsorption isotherm and selectivity towards SA onto MIP and non-imprinted polymer (NIP) were investigated, indicating that MIP had splendid recognizing ability and a superior specific adsorption capacity (145.19 mg g−1) compared to that of NIP (64.30 mg g−1) at 35 °C. Meanwhile, MIP was regenerated and found to be suitable for reuse in successive adsorption–desorption cycles five times without significant loss in the adsorption capacity. The results suggested that MIP could be used as an excellent adsorbent for the efficient removal of SA from aqueous solution.
✓ 已验证
产品关联
DOI
高影响因子
Molecular Catalysis
·
2020
·
IF 3.687
Yi Yu,Fanfan Li,Zhouxuan Zang,Li Xu,Guoji Liu
Catalytic oxidation of 2-methylnaphthalene to 2-methyl-1,4-naphthoquinone (vitamin K 3 ) is a significant pathway to produce vitamin groups K. High pollution and low-productivity of the traditional method require a greener catalyst and process. In this work, Al/Ti-SBA-15 with different n Si /n Al and n Si /n Ti ratios were hydrothermally prepared in mild acidic condition and tested in partial oxidation of 2-methylnaphthalene. Commercial zeolites NaY, β and ZSM-5 were applied to investigate the influence of mass transfer resistance and acidity on catalytic performance. Catalysts were characterized by XRD, N 2 adsorption-desorption, TEM, NH 3 -TPD, FTIR and Py -FTIR. We have found that the 2-methylnaphthalene conversion and vitamin K 3 selectivity depend strongly on the mesoporous structure as well as Brönsted acid concentration and strength. Irregular micropores and strong acidity will accelerate the cleavage of C = C in aromatic rings, leading to the production of phthalic anhydride. DFT calculation reveals that incorporation of aluminum in SBA-15 can reduce the energy gap, facilitating the electron transfer. And as a consequence of the substitution of Al in tetrahedral positions in SBA-15, Al-SBA-15 (10) gives the best result with 72% yield to vitamin K 3 . This catalyst markedly reduces the activation energy due to the modified activated center. Repeated experiments recommend that Al-SBA-15 is a steady and high-efficiency catalyst for the production of vitamin K 3 .
✓ 已验证
产品关联
DOI
高影响因子
CHINESE JOURNAL OF CATALYSIS
·
2015
·
IF 1.964
Huimin Liu,Yuming Li,Hao Wu,Jiaxiong Liu,Dehua He
Organic compounds containing multiple hydroxyl groups, namely α-cyclodextrin and γ-cyclodextrin, were used as additives for promoting Ni dispersion on supported Ni/SBA-15 catalysts. Catalysts prepared using modified and unmodified impregnation methods were characterized using N 2 adsorption-desorption isotherms, X-ray diffraction, transmission electron microscopy, temperature-programmed reduction, and thermogravimetric analysis, and their catalytic performance in the CO 2 reforming of methane (CRM) to syngas was evaluated. The results show that compared with Ni/SBA-15 prepared using a conventional impregnation method, the cyclodextrin-modified catalysts had smaller NiO particles. They also exhibited higher catalytic activity and had stronger ability to resist carbon deposition in the CRM. Mechanistic studies showed that for the unmodified catalysts, Ni 2+ could migrate into the channels of SBA-15 as a result of concentration differences, and the Ni species were sintered during the following thermal treatment processes, and could not be well dispersed. In contrast, various types of complex were formed between Ni(NO 3 ) 2 and the cyclodextrins, and this would be favorable for Ni 2+ being taken into the channels of the SBA-15. The presence of cyclodextrins was beneficial to the mutual isolation of Ni species, and finally resulted in better dispersion of Ni species.
✓ 已验证
产品关联
DOI
高影响因子
Catalysis Science & Technology
·
2016
·Vol. 6
·期 16
·6406-6416
·
IF 5.287
Mengshuai Liu,Kunqi Gao,Lin Liang,Jianmin Sun,Li Sheng,Masahiko Arai
The combination of a metal-modified SBA-15 catalyst with potassium iodide was developed as heterogeneous dual catalysts for chemical fixation of CO2 to cyclic carbonates. It was observed that the binary Zn-SBA-15/KI catalysts were the most efficient among various metal-modified SBA-15/KI catalysts and showed an excellent synergetic effect in promoting the reaction under mild conditions. Moreover, the effects of reaction parameters on cycloaddition of CO2 with propylene oxide (PO) to propylene carbonate (PC) were optimized. Under the optimal conditions determined, the Zn-SBA-15/KI catalytic system was also versatile in CO2 cycloaddition with other epoxides. Additionally, the mechanistic details for the fixation of CO2 into a cyclic carbonate catalyzed by SBA-15/KI and Zn-SBA-15/KI were also contrastively elucidated using the density functional theory (DFT) method. The DFT results suggested that the zinc-modified and unmodified catalysts showed different coupling modes of CO2, and the ring-opening reaction was the rate-determining step in the SBA-15/KI catalyzed cycloaddition reaction, but the zinc-modified SBA-15/KI catalysts could enhance the CO2 cycloaddition, as the formation of a stable complex was beneficial to CO2 trapping. As a result, the ring-closing reaction became the rate-determining step in the Zn-SBA-15/KI catalyzed cycloaddition reaction, which was a promising result to guide the catalyst design for CO2 conversion.
✓ 已验证
产品关联
DOI
高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
·
2017
·
IF 3.615
Rong He,Zhihong Wang,Lei Tan,Yi Zhong,Weiming Li,Da Xing,Chaohai Wei,Youwen Tang
We developed two types of novel highly ordered Ni 2+ imprinted mesoporous organosilica materials (SBA-15 (NiIMS1) and MCM-41 (NiIMS2)) through co-condensation for selective adsorption of Ni 2+ from electroplating Ni 2+ effluents. FTIR and solid-state 13 C NMR spectra demonstrated the successful embedment of functionalized iminodiacetic acid and ethanediamine chelating groups in NiIMS1 and NiIMS2, respectively. X-ray photoelectron spectroscopy analysis confirmed that Ni 2+ was coordinated by N atom and carboxyl O atom of the functional groups. Furthermore, NiIMS1 and NiIMS2 displayed highly ordered periodic hexagonal P6mm meso-structure, large surface area, and highly specific recognition ability toward Ni 2+ . The adsorption experimental results proved that NiIMS1 was suitable for acidic wastewater treatment , whereas NiIMS2 was fit for alkaline wastewater. The saturated adsorption capacity of NiIMS2 was 20.8 mg/g at pH 6.0, and that of NiIMS1 reached up to 22.9 mg/g at pH 3.0. The values of selectivity coefficients of NiIMS1 and NiIMS2 for five competing metal ions ranged from 46.4 to 12.4 and 36.9 to 18.8, respectively. The adsorption efficiency of NiIMS1 was above 92.5% even after seven extraction-stripping cycles, while that for NiIMS2 was 90.9%. The real sample adsorption experiments demonstrated that these mesoporous organosilica materials have high potential for water treatment applications.
✓ 已验证
产品关联
DOI
高影响因子
CONSTRUCTION AND BUILDING MATERIALS
·
2025
·
IF 8
Shuyang Shi,Shuxian Zheng,Kun Zeng,Liang Yue,Xianlai Zhang,Wenhui Rao,Chuanbai Yu
The inflammability of epoxy resins (EPs) severely limits their safe and reliable application. The design and application of flame retardants has enormous potential for increasing the fire safety of EP composites. In the present study, a novel organic-inorganic nanohybrid material (VDSZ), consisting of mesoporous silica (SBA-15), P/N/Si-containing compound and the transition metal (Zn), was constructed by in-situ functional modification of the inner and outer surfaces of SBA-15. That is, Zn was in-situ modified on the inner pore surface of SBA-15, and phosphorus-containing compound was in-situ grafting onto outer surface of SBA-15 by Schiff base reaction. The results showed that EP/VDSZ-3 composite had a significant improvement in flame-retardant properties. The limiting oxygen index (LOI) for EP/VDSZ-3 increased from 24.5 % (EP) to 30.8 %, resulting in a UL-94 V-0 rating. Furthermore, the findings of the cone calorimeter test (CCT) demonstrated that, in comparison with pure EP, the peak heat release rate, total smoke generation and smoke production release of EP/VDSZ-3 decreased by 29.16 %, 25.95 %, and 30.90 % respectively. Moreover, the impact strength of EP/VDSZ-1 was 40 % higher than that of pure EP. Meanwhile, the thermal stability of EP composites improved dramatically as the VDSZ increased. This study found that creating a multi-level structure provided a fresh idea for simultaneously boosting polymer flame retardancy, smoke suppression and thermal stability, which will be applied to building materials with flame retardant requirements.
✓ 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）