Journal of Bioresources and Bioproducts
·
2020
·
IF 0
Mingxue Su,Wenzhi Li,Qiaozhi Ma,Bowen Zhu
Liquid fuel intermediates could be produced via aldol condensation reaction between furfural or 5-hydroxymethylfurfural (HMF) and acetone. It was found that iron-modified MCM-41 zeolite can be an effective Lewis acid catalyst for C—C bond formation via aldol condensation of furfural or HMF with acetone. The 4-(2-furyl)-3-buten-2-one and 1, 5-di-2-furanyl-1, 4-pentadien-3-one (FAc and F 2 Ac), or 1, 5-di-2-furanyl-1, 4-pentadien-3-one and 1, 5-bis[(5- hydroxlmethyl )-2- furanyl ]-1, 4-pentadien-3-one (HAc and H 2 Ac), as two main condensation products of furfural with acetone or HMF with acetone, were observed. After 24 h at 160 °C, 86.9% conversion of furfural with 60.0% yield of the FAc as well as 7.5% yield of the F 2 Ac and 88.9% conversion of the HMF with 41.1% yield of the HAc as well as 3.5% yield of the H 2 Ac were achieved. Although furfural or HMF conversion was almost same after 24 h at 160 °C, iron-modified MCM-41 zeolite catalyst displayed an enhanced selectivity to condensation products of furfural with acetone. In addition, catalysts showed an improved selectivity to the F 2 Ac and H 2 Ac at higher reaction temperature. The reusability and regeneration studies showed that iron-modified MCM-41 zeolite catalyst could not be reused directly, but could be regenerated by calcination in air, and the catalytic performance of regenerated catalyst was acceptable.
研究领域:
化学工程
·
催化材料
·
可再生能源
✓ 已验证
DOI
JOURNAL OF RARE EARTHS
·
2017
·
IF 2.429
Yang Han,Bo Wen,Mingyuan Zhu,Bin Dai
Herein, lanthanum was incorporated via hydrothermal synthesis into a MCM-41 framework structure with La/Si molar ratios from 0.01 to 0.1. Samples of NiO supported on LaMCM-41 were prepared using the impregnation method. The catalyst performance was evaluated using a fixed bed CO methanation reactor. A Ni/LaMCM-41 catalyst with La/Si = 0.1 shows the best catalytic performance with a CO conversion of almost 100% and a CH 4 selectivity of 89.5% at 250 °C under a pressure of 1.5 MPa and at an airspeed of 36,000 mL/(g·h). Compared with Ni–La/MCM-41(La/Si = 0.1) and Ni/MCM-41 prepared via the impregnation method, Ni/LaMCM-41(La/Si = 0.1) shows a higher CO conversion and CH 4 selectivity. In a 100 h stability test, the Ni/LaMCM-41(La/Si = 0.1) catalyst shows excellent stability; furthermore, the CO conversion is always greater than 98.0%, which is significantly better than the results for Ni/MCM-41. We experimentally demonstrate that elemental La enters the framework of MCM-41. The Ni/LaMCM-41 catalyst performs well because the La reduces the average particle size of the NiO particles and enhances the interaction between NiO and MCM-41; moreover, the introduction of La significantly inhibits the sintering of the catalyst and the formation of carbon deposits .
研究领域:
催化化学
·
材料科学
·
能源化学
·
工业催化
·
多孔材料
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化学工程
·
环境催化
✓ 已验证
DOI
高影响因子
CHEMOSPHERE
·
2022
·
IF 8.943
Dongpo Liu,Muxin Lin,Weirui Chen,Jing Wang,Xingmei Guo,Xukai Li,Laisheng Li
Fe-MCM-41 had been widely used as ozonation catalyst, however, the existence of large amount of hydrophilic silanol hindered its interfacial reaction with O 3 and pollutants. To solve this problem, F–Fe-MCM-41 was synthesized by co-doping F and Fe into the framework of MCM-41 to replace silanol with Si–F groups through a one-step hydrothermal method. F introduced hydrophobic sites which contributed to more ibuprofen (IBP) chemisorption on the surface of F–Fe-MCM-41. Moreover, doping F also enhanced the acidity, which accelerated O 3 decomposition into •OH. F–Fe-MCM-41/O 3 exhibited notably activity with 96.6% IBP removal efficiency within 120 min, while only 78.5% and 80.9% in O 3 alone and Fe-MCM-41/O 3 , respectively. Surface Lewis acid sites and metal hydroxyl groups were considered as important factors for O 3 activation and •OH generation. F–Fe-MCM-41 exhibited excellent catalytic performance under acidic and alkaline conditions. Comparative experiments revealed that F doping improved the interfacial reaction, especially the interfacial electron transfer , which resulted in the high catalytic activity of F–Fe-MCM-41. F–Fe-MCM-41 possessed good stability and reusability, with only 5.7% decline for IBP removal in five successive cycles. Furthermore, the possible degradation path of IBP was proposed according to DFT calculation and GC-MS analysis.
研究领域:
环境科学
·
催化材料
✓ 已验证
产品关联
DOI
PubMed
高影响因子
POLYMER BULLETIN
·
2020
·Vol. 78
·期 8
·4551-4568
·
IF 2.014
Li Yinhui,Li Pengwei,Lu Jingqiong,Zhao Yansheng
Stimuli-responsive hydrogels are attracting extensive attention in drug delivery system. Here, a novel pH, thermo and salt sensitivity of composite hydrogels was synthesized in situ from polysuccinimide modified by γ-aminopropyltriethoxysilane with mesoporous molecular sieves (MCM-41) as only crosslinking agent for controlled salicylic acid release. Morphologies and thermal behaviors of KPAsp/MCM-41 hydrogels were characterized by scanning electron microscopy and thermogravimetric analysis. Swelling dynamic behaviors, pH, thermo and salt sensitivities and drug releasing capacities of composite hydrogels were also systematically investigated. The obtained results show that multi-responsive hydrogels are very sensitive to environmental pH, external temperature and ionic valence, which indicated that the MCM-41 addition not only can ameliorate the network structure, but also can enhance the drug loading and releasing capacity. The controlled salicylic acid release rates of MCM-41/KPAsp hydrogels can reach to 33.6% and 61.2% in simulated gastric fluid (pH = 1.2) and in simulated intestinal fluid at (pH = 7.4) at 37 °C, respectively. The as-synthesized multi-responsive hydrogels reported here are promising candidates for application in targeted drug delivery system.
研究领域:
材料科学
·
药学
·
生物医学工程
✓ 已验证
DOI
高影响因子
Molecular Catalysis
·
2022
·
IF 5.089
Kuan Wang,Zhe Cao,Junlei Wang,Zhen-Hong He,Dan Wang,Rong-Rong Zhang,Weitao Wang,Yang Yang,Zhao-Tie Liu
The development of non-precious metal catalysts in heterogeneous catalytic processes is of great importance to the hydrogenation of quinolines for both theoretical and industrial applications. Herein, an effective non-precious metal catalyst, 58% Fe 4 Ni 6 Cu 5 /MCM-41, was developed to catalyze the hydrogenation of quinolines under the green and mild conditions, which can achieve 97.5% conversion and exceeding 98% selectivity to tetrahydroquinoline in solvent-free at low temperature of 50 °C. Moreover, the acceptable results of the reusability and gram scale-up experiments proved an industrial application potential of the as-prepared catalyst. Meanwhile, in cyclohexane system, 58% Fe 4 Ni 6 Cu 5 /MCM-41 catalyst can further realize a higher activity of the hydrogenation at a lower temperature of 40 °C, achieving 98.2% conversion and 98% selectivity to tetrahydroquinoline. The existence of Fe-Ni and Ni-Cu alloys in Fe 4 Ni 6 Cu 5 /MCM-41 catalyst was demonstrated by TEM, XRD, XPS, H 2 -TPD, and Raman spectroscopy. And, Fe-Ni and Ni-Cu alloys can be well dispersed onto MCM-41 molecular sieves. For Fe 4 Ni 6 Cu 5 /MCM-41 catalyst, quinoline molecules can be adsorbed by Fe 3+ species on the surface of Fe-Ni alloy through the coordination, while hydrogen molecules can be adsorbed and activated by Ni-Cu alloy. Under the synergism of Fe-Ni and Ni-Cu alloys, the highly effective and selective hydrogenation of quinolines was achieved at low temperature and in solvent-free system. The present approach offers a prospective idea for building non-precious metal catalysts to realize the effective hydrogenation of N-heterocyclic compounds under mild conditions.
研究领域:
催化化学
·
材料科学
·
绿色化学
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2020
·
IF 3.573
Wei Liu,Yuqing Zhang,Longfei Zhang,Jiaqi Guo,Jiahao Wei
A polysulfone (PSf) ultrafiltration (UF) membrane without a chemical reaction process is unable to deeply clean industrial wastewater and prone to fouling. In this work, a 30 mol % Cu-substituted brownmillerite SrCuxCo1–xO3−λ (SCC37, λ ≥ 0.5)-deposited MCM-41 hybrid catalyst with 40 wt % SCC37 (SCCM-40%) was synthesized and then blended into the PSf membrane by the phase inversion method. The resultant PSf/SCCM UF membrane with catalytic oxidation and antifouling properties was tested via peroxymonosulfate (PMS) activation. As characterized by transmission electron microscopy and X-ray diffraction analyses, the SCC37 catalysts (5–10 nm) with a brownmillerite structure were evenly scattered on the surface of MCM-41. Notably, the uniform distribution of SCCM-40% in the composite membrane was contributed to the favorable degradation capacity for membrane-permeable rhodamine B (RhB) because of the massive 1O2 and SO4•– generated by PMS activation. The RhB degradation effect of the membrane remained high in the pH range of 3–9 and in the presence of humic acid. Moreover, the PSf/SCCM UF membrane demonstrated favorable long-term self-cleaning and antifouling properties after a PMS-based cleaning process. The results highlight the potential of this catalytic UF membrane in the treatment of industrial wastewater.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
ENERGY & FUELS
·
2018
·
IF 3.024
Lincai Peng,Xueying Gao,Xin Yu,Hui Li,Junhua Zhang,Liang He
An integrated multistep catalytic process in a one-pot cascade model to realize conversion is preferred in terms of process economics and energy efficiency. Here, we present the noble-metal-free but highly effective catalytic transfer hydrogenation and acid-catalyzed conversion of biomass-derived furfural for direct production of biofuel alkyl levulinate using alcohols as the hydrogen donor and reaction medium. With optimization of the process variables, a high yield of alkyl levulinate at up to 85.3% could be captured under mild conditions in isopropanol medium with the combination of Zr-MCM-41 and Amberlyst-15 catalysts. The reaction proceeds via the catalytic transfer hydrogenation of furfural to furfuryl alcohol over Zr-MCM-41, which is then converted to alkyl levulinate by an Amberlyst-15 acid catalyst. The spent hybrid catalysts could be effectively recovered from the resulting reaction mixture and reused 5 times with little deactivation after plain regeneration treatment.
研究领域:
化学工程
·
可再生资源与环境科学
✓ 已验证
产品关联
DOI
高影响因子
Foods
·
2024
·Vol. 13
·期 16
·2539
·
IF 4.7
Zhonghui Liu,Tieliang Liu,Run Liu,Qi Zhou,Yandaizi Zhou,Yi Zhang,Mingming Zheng
Rapeseed oil is a widely consumed edible oil that contains varieties of beneficial micronutrients such as tocopherols and phytosterols; however, the high acid value due to increased free fatty acid can imperil the oil quality and safety. This paper proposed the enzymatic deacidification for high-acid rapeseed oil and simultaneous production of functional diacylglycerols (DAGs) catalyzed by self-made immobilized lipase CALB@MCM-41-C8. The results indicate that the carrier of molecular sieve MCM-41 exhibited a sufficient surface area of 1439.9 m2/g and a proper pore size of 3.5 nm, promoting the immobilization of lipase CLAB. Under the optimal reaction conditions, the acid value of rapeseed oil was largely decreased from 15.3 mg KOH/g to 1.7 mg KOH/g within 3 h, while DAG content was increased from 1.2% to 40.2%. The antioxidant stability of rapeseed oil was also increased from 4.3 h to 7.6 h after enzymatic deacidification. Besides, the deacidified rapeseed oil exhibited fatty, bitter almond aromas, compared to the picked-vegetable, spicy, and pungent aromas for high-acid oil. Finally, the catalytic stability and applicability of CALB@MCM-41-C8was validated, thus demonstrating the great potential of CALB@MCM-41-C8in green refining of edible oils and sustainable synthesis of functional lipids.
研究领域:
食品科学
·
生物技术
·
化学工程
·
农业化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF POROUS MATERIALS
·
2024
·Vol. 31
·期 3
·913-922
·
IF 2.5
Wu Chengqiang,Li Yingping,Ma Yongping,Lei Yuexiang,Wang Meijing,Chen Zhen
A novel loaded copper ion catalyst, Cu/MCM-41-SH, was synthesized using CuI-modified thiol-functionalized MCM-41 silica-based materials, and the prepared catalysts were characterized by XPS, FT-IR, SEM and N 2 adsorption–desorption techniques. The XPS results indicated that the chemical valence of the copper that adsorbed on the CuI/MCM-41-SH surface was + 1 valence. N 2 adsorption–desorption showed that the adsorption–desorption isotherms of both MCM-41 and CuI/MCM-41-SH materials were type IV with H4-type hysteresis loops, and the pore size and specific surface area of the materials were reduced. This work demonstrates that that when the reaction time was 2 h, the reaction temperature was 80 ℃ and the catalyst dosage was 100 mg, the conversion of tetralin was obtained as 92.63% and the selectivity of α-tetralone was 84.84%. The catalyst showed good reusability in the three recovery experiments. These results show that the catalyst has potential applications for green and sustainable development.
研究领域:
材料科学
·
催化
·
纳米技术
·
环境化学
·
绿色化学
✓ 已验证
DOI
高影响因子
FUEL
·
2024
·
IF 6.7
Guang-Hui Liu,Wen-Ao Shi,Jun Li,Han Wang,Ai-Min Wang,Yu-Hong Kang,Yong Gao,Ni Bai,Jie Kang,Chen Shi,Xian-Yong Wei
To produce high-density liquid fuels from lignite, a novel Ni-based bifunctional MCM-41/ β composite zeolite (Ni@ M / β ) is reported for the catalytic hydroconversion (CHC) of lignite-derived aryl ethers to high-yield polycyclic alkanes (PCAs). Ni@ M / β has a three-dimensional channel-type hierarchical porous texture with β as the core and MCM-41 as the shell. Stable Brønsted/Lewis acid sites and abundant internal/inter-zeolite defects also effectively promote the CHC of aryl ethers to PCAs. Under optimal conditions (5 MPa initial H 2 pressure and 160 °C), selectivities of 2-(benzyloxy)naphthalene (BON) and benzyloxybenzene derived PCAs are as high as 76.0 and 90.5 %, respectively, with dimers and trimers dominating. DFT calculation based on electrostatic potential distribution on the van der Waals surface and Mulliken charge distribution of BON and derived oxygenated monomers shows that aromatic intermediates with >C aromatic OH have multiple accessible sites and are easy to bind with cation/radical fragments. Therefore, it is speculated that PCAs are mainly derived from C-C coupling induced by cation/radical fragments after the activation of aromatic α -carbon. In addition, the activation of H 2 to H + , H · , δ+ H ··· H δ- , and H ··· H is mainly attributed to the strong Ni- M / β interaction and abundant defects. The whole CHC process is triggered mainly by the adsorption of H + released by Ni@ M / β at O sites of aryl ethers, and >C aliphatic -O- bridged bond cleavage is dominant. During this period, benzyl cation/radical produced by >C-O- bond cleavage and aromatic α -carbon activation (mainly) is coupled/reformed with adjacent aromatic fragments into corresponding polymers with non-oxygen bridged bonds, which are more easily converted to PCAs. This polycrystalline composite strategy improves the accessibility of large-sized molecules to active centers, and then increases the yields of PCAs, which is attractive for the clean and efficient conversion of lignite-derived oils to high-density liquid fuels.
研究领域:
化学工程
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
Catalysis Science & Technology
·
2018
·Vol. 8
·期 16
·4241-4256
·
IF 5.365
Xiaochao Xian,Chao Ran,Peng Yang,Yirong Chu,Shuo Zhao,Lichun Dong
The effect of the acidity of HZSM-5/MCM-41 hierarchical zeolite on its catalytic performance in the supercritical catalytic cracking of n-dodecane was investigated by controlled ion exchange with NaCl solution under ultrasonic conditions. XRD and nitrogen adsorption–desorption results showed that the crystal and porous properties were not affected, while NH3-TPD, the probe reaction of n-hexane cracking and temperature-programmed surface reaction (TPSR) of n-dodecane demonstrated that strong Brønsted acid sites were replaced by Na+ (weak Lewis acid sites) to different extents with varying concentrations of NaCl solution. Although the initial conversion of n-dodecane during the supercritical catalytic cracking was slightly reduced, its stability was greatly enhanced by ion exchange. An ultrastable catalyst with no obvious deactivation within 3 h of time on stream (TOS) was obtained by ion exchange with 0.8 M NaCl solution. A mechanism describing the role of the acid sites residing in both micropores and mesopores of the hierarchical catalyst was proposed based on coke analysis.
研究领域:
化学工程
·
催化科学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2016
·
IF 3.15
Xiao-Na Wei,Hui-Long Wang,Zhen-Duo Li,Zhi-Qiang Huang,Hui-Ping Qi,Wen-Feng Jiang
The mesoporous MCM-41@mTiO 2 core-shell composite microspheres were synthesized successfully by combining sol-gel and simple hydrothermal treatment. The morphology and microstructure characteristics of the synthesized materials were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), N 2 adsorption-desorption measurements, X-ray powder diffraction (XRD), UV–vis diffuse reflectance spectra (UV–vis/DRS) and Fourier transform infrared spectroscopy (FT-IR). The results indicate that the composite material possesses obvious core/shell structure, a pure mesoporous and well-crystallized TiO 2 layer (mTiO 2 ), high specific surface area (316.8 m 2 /g), large pore volume (0.42 cm 3 /g) and two different pore sizes (2.6 nm and 11.0 nm). The photocatalytic activity of the novel MCM-41@mTiO 2 composite was evaluated by degrading 2- sec -butyl-4,6-dinitrophenol (DNBP) in aqueous suspension under UV and visible light irradiation. The results were compared with commercial anatase TiO 2 and Degussa P25 and the enhanced degradation were obtained with the synthesized MCM-41@mTiO 2 composite under the same conditions, which meant that this material can serve as an efficient photocatalyst for the degradation of hazardous organic pollutants in wastewaters.
研究领域:
材料科学
·
环境科学
✓ 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）