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Enhanced activation of persulfate using mesoporous silica spheres augmented Cu–Al bimetallic oxide particles

《化学科学与工程前沿(英文)》 2023年 第17卷 第10期   页码 1581-1592 doi: 10.1007/s11705-023-2327-7

摘要: Herein, Cu–Al bimetallic oxide was synthesized and mixed with mesoporous silica spheres via a simple hydrothermal method. The prepared sample was then analyzed and employed to activate potassium peroxydisulfate for bisphenol A removal. Based on the results of X-ray diffraction, scanning electron microscopy, and energy dispersion spectroscopy, Cu–Al bimetallic oxide was determined as CuO-Al2O3, and mesoporous silica spheres were found around the these particles. At 30 min, a bisphenol A degradation level of 90% was achieved, and it remained at over 60% after five consecutive cycles, indicating the catalyst’s superior capacity and stability. In terms of removal performance, the radical pathway (including SO4•‒, OH •, and O2•‒) and singlet oxygen (1O2) played minor roles, while electron migration between bisphenol A, potassium peroxydisulfate, and the catalyst played a dominant role. The introduction of Al2O3 promoted the formation of surface oxygen vacancies, which improved ligand complex formation between potassium peroxydisulfate and the catalyst, thereby facilitating electron migration. Furthermore, mesoporous silica spheres augment not only enhanced bisphenol A adsorption but also alleviated Cu leaching. Overall, this work is expected to provide significant support for the rational development of catalysts with high catalytic activity for persulfate activation via surface electron migration.

关键词: Cu–Al bimetallic oxides     mesoporous silica spheres     peroxydisulfate     bisphenol A    

The modification of titanium in mesoporous silica for Co-based Fischer–Tropsch catalysts

《化学科学与工程前沿(英文)》 2022年 第16卷 第8期   页码 1224-1236 doi: 10.1007/s11705-022-2139-1

摘要: Ordered SBA-15 mesoporous silica with incorporated titanium was successfully synthesized via a one-pot hydrothermal crystallization method. The characterization including powder X-ray diffraction, Brunauer–Emmett–Teller, transmission electron microscope, temperature-programmed reduction, temperature-programmed desorption, Fourier transform infrared and ultraviolet-visible-near infrared spectrometer was performed to explore the physical and chemical structures of both the supports and the catalysts. The results showed that titanium was successfully incorporated into the mesoporous silica framework with a limited amount of titanium (Si/Ti > 20), and the mesoporous structure was retained. However, the increased titanium content inevitably resulted in the formation of anatase TiO 2 particles on the support surface. The increased incorporated titanium strengthened the interactions between cobalt species and supports, which was favorable for the cobalt species dispersion, despite the limited cobalt oxide reducibility. The enhanced metal-support interactions were beneficial for the CO/H2 ratio at the active cobalt sites, which facilitated the formation of more C5+ hydrocarbons. This study provides a promising method for support modification with incorporated-heteroatoms for the rational development of Fischer–Tropsch catalysts.

关键词: Fischer–Tropsch synthesis     titanium incorporation     mesoporous silica     metal-support interactions     C5+ selectivity    

Sulfonic acid-functionalized mesoporous silica catalyst with different morphology for biodiesel production

《化学科学与工程前沿(英文)》 2022年 第16卷 第8期   页码 1198-1210 doi: 10.1007/s11705-021-2133-z

摘要: Sulfonic acid functionalized mesoporous silica based solid acid catalysts with different morphology were designed and fabricated. The synthesized materials were characterized by various physicochemical and spectroscopic techniques like scanning electron microscope-energy dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, Brunauer–Emmett–Teller surface area, thermogravimetric analysis and n-butylamine acidity. The shape of catalysts particles plays an important role in its activity. The sulfonic acid functionalized mesoporous silica catalysts of spherical shape and the cube shape were assessed for catalytic activity in biodiesel production. The catalytic biodiesel production reaction over the catalysts were studied by esterification of free fatty acid, oleic acid with methanol. The effect of various reaction parameters such as catalyst concentration, acid/alcohol molar ratio, catalyst amount, reaction temperature and reaction time on catalytic activity were investigated to optimize the conditions for maximum conversion. It was sulfonated cubic shape mesoporous silica which exhibited better activity as compared to the spherical shape silica catalysts. Additionally, the catalyst was regenerated and reused up to three cycles without any significant loss in activity. The present catalysts exhibit superior performance in biodiesel production and it can be used for the several biodiesel feedstock’s that are rich in free fatty acids.

关键词: solid acid catalyst     mesoporous silica     sulfonic acid     biodiesel     esterification     oleic acid    

Synthesis of ordered cerium-doped cubic mesoporous silica using long-chain ionic liquid as template

YUE Hongxia, ZHAO Hongmei, LIU Longjiang, WANG Siping, Ruan Qiong, WANG Tongwen

《化学科学与工程前沿(英文)》 2008年 第2卷 第2期   页码 135-139 doi: 10.1007/s11705-008-0031-2

摘要: The long-chain ionic liquid 1-hexadecyl-3-methylimidazolium chloride (CmimCl) was used as a template to prepare cerium-doped MCM-48 materials in basic medium by a hydrothermal synthesis procedure. The effect of the amount of Ce salt and CmimCl/Si on the synthesis were discussed in detail. This mesoporous material exhibits a pore architecture which is cubic 3 gyroid and possesses a large surface area and a narrow pore distribution. Cerium in calcined porous framework exists in the form of well-dispersed tetrahedral coordination. The CmimCl shows a high tendency toward self-aggregation that allows the formation of the cerium-doped gyroid mesostructure by using the appropriate amount of Ce salt.

关键词: mesoporous     CmimCl/Si     tendency     mesostructure     synthesis procedure    

Enhanced Fenton-like process over Cu/L(+)-ascorbic acid co-doping mesoporous silica for toxicity reduction

《环境科学与工程前沿(英文)》 2023年 第18卷 第4期 doi: 10.1007/s11783-024-1804-7

摘要:

● Cu-C-MSNs are developed via a co-doping step of Cu with L(+)-ascorbic acid.

关键词: Cation-π structures     Polarization electric field     Fenton-like process     Contaminants cleavage    

Fe3O4 encapsulated mesoporous silica nanospheres with tunable size and large void

Tingting LIU, Lihong LIU, Jian LIU, Shaomin LIU, Shi Zhang QIAO

《化学科学与工程前沿(英文)》 2014年 第8卷 第1期   页码 114-122 doi: 10.1007/s11705-014-1413-2

摘要: Magnetic Fe O and mesoporous silica core-shell nanospheres with tunable size from 110–800 nm were synthesized via a one step self-assembly method. The morphological, structural, textural, and magnetic properties were well-characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, N adsorption-desorption and magnetometer. These nanocomposites, which possess high surface area, large pore volume and well-defined pore size, exhibit two dimensional hexagonal ( 6mm) mesostructures. Interestingly, magnetic core and mesoporous silica shell nanocomposites with large void pore (20 nm) on the shell were generated by increasing the ratio of ethanol/water. Additionally, the obtained nanocomposites combined magnetization response and large void pore, implying the possibility of applications in drug/gene targeting delivery. The cell internalization capacity of NH -functionalized nanocomposites in the case of cancer cells (HeLa cells) was exemplified to demonstrate their nano-medicine application.

关键词: mesoporous silicas     magnetic nanoparticles     core-shell nanoparticles     cell uptake    

Surface modification of mesoporous silica nanoparticle with 4-triethoxysilylaniline to enhance seawater

Jian Wang, Qun Wang, Xueli Gao, Xinxia Tian, Yangyang Wei, Zhen Cao, Chungang Guo, Huifeng Zhang, Zhun Ma, Yushan Zhang

《环境科学与工程前沿(英文)》 2020年 第14卷 第1期 doi: 10.1007/s11783-019-1185-5

摘要: Mesoporous silica nanoparticle was modified with 4-triethoxysilylaniline. AMSN-based TFN-RO membranes were prepared for seawater desalination. Water transport capability of the AMSN was limited by polyamide. Polyamide still plays a key role in permeability of the TFN RO membranes. Mesoporous silica nanoparticles (MSN), with higher water permeability than NaA zeolite, were used to fabricate thin-film nanocomposite (TFN) reverse osmosis (RO) membranes. However, only aminoalkyl-modified MSN and low-pressure (less than 2.1 MPa) RO membrane were investigated. In this study, aminophenyl-modified MSN (AMSN) were synthesized and used to fabricate high-pressure (5.52 MPa) RO membranes. With the increasing of AMSN dosage, the crosslinking degree of the aromatic polyamide decreased, while the hydrophilicity of the membranes increased. The membrane morphology was maintained to show a ridge-and-valley structure, with only a slight increase in membrane surface roughness. At the optimum conditions (AMSN dosage of 0.25 g/L), when compared with the pure polyamide RO membrane, the water flux of the TFN RO membrane (55.67 L/m2/h) was increased by about 21.6%, while NaCl rejection (98.97%) was slightly decreased by only 0.29%. However, the water flux of the membranes was much lower than expected. We considered that the enhancement of RO membrane permeability is attributed to the reduction of the effective thickness of the PA layer.

关键词: Thin film nanocomposite membrane     Reverse osmosis     Seawater desalination     Aminophenyl-functionalized mesoporous silica nanoparticles    

Crystalline mesoporous transition metal oxides: hard-templating synthesis and application in environmental

Zhen MA, Bei ZHOU, Yu REN

《环境科学与工程前沿(英文)》 2013年 第7卷 第3期   页码 341-355 doi: 10.1007/s11783-012-0472-1

摘要: Mesoporous silicas such as MCM-41 and SBA-15 possess high surface areas, ordered nanopores, and excellent thermal stability, and have been often used as catalyst supports. Although mesoporous metal oxides have lower surface areas compared to mesoporous silicas, they generally have more diversified functionalities. Mesoporous metal oxides can be synthesized via a soft-templating or hard-templating approach, and these materials have recently found some applications in environmental catalysis, such as CO oxidation, N O decomposition, and elimination of organic pollutants. In this review, we summarize the synthesis of mesoporous transition metal oxides using mesoporous silicas as hard templates, highlight the application of these materials in environmental catalysis, and furnish some prospects for future development.

关键词: mesoporous materials     silica     metal oxide     hard-templating     environmental catalysis    

Fabrication of bimetallic Cu–Zn adsorbents with high dispersion by using confined space for gas adsorptive separation

《化学科学与工程前沿(英文)》   页码 1623-1631 doi: 10.1007/s11705-022-2202-y

摘要: The number of active components and their dispersion degree are two key factors affecting the performance of adsorbents. Here, we report a simple but efficient strategy for dispersing active components by using a confined space, which is formed by mesoporous silica walls and templates in the as-prepared SBA-15 (AS). Such a confined space does not exist in the conventional support, calcined SBA-15, which does not contain a template. The Cu and Zn precursors were introduced to the confined space in the AS and were converted to CuO and ZnO during calcination, during which the template was also removed. The results show that up to 5 mmol·g–1 of CuO and ZnO can be well dispersed; however, severe aggregation of both oxides takes place in the sample derived from the calcined SBA-15 with the same loading. Confined space in the AS and the strong interactions caused by the abundant hydroxyl groups are responsible for the dispersion of CuO and ZnO. The bimetallic materials were employed for the adsorptive separation of propene and propane. The samples prepared from the as-prepared SBA-15 showed superior performance to their counterparts from the calcined SBA-15 in terms of both adsorption capacity of propene and selectivity for propene/propane.

关键词: bimetallic adsorbents     confined space     mesoporous silica     propene/propane separation    

Magnetic KIT-6 nano-composite and its amino derivatives as convenient adsorbent for U(VI) sequestration

《化学科学与工程前沿(英文)》 2023年 第17卷 第12期   页码 2037-2049 doi: 10.1007/s11705-023-2358-0

摘要: Although mesoporous silica with magnetically hybridized two-dimensional channel structures has been well studied in recent years, it remains a challenge to fabricate the counterpart with macroporous three-dimensional cubic structures since the highly acidic preparation conditions lead to dissolution of magnetic particles. Herein, we successfully prepared magnetic KIT-6 nano-composite and its amino derivatives by bearing acid-resistant iron oxide. The prepared materials exhibited excellent properties for U(VI) ions removal from aqueous solutions under various conditions. The experimental data show that the U(VI) adsorption features fast adsorption kinetics, high adsorption capacity and ideal selectivity toward U(VI). The adsorption process is of spontaneous and endothermic nature and ionic strength independence, and the adsorbents can be easily regenerated by acid treatment. Compared to pristine KIT-6, the introduction of magnetism does not reduce the efficiency of the material to remove U(VI) while exerting its role as a recovery adsorbent. The findings of this work further demonstrate the potential broad application prospects of magnetic hybrid mesoporous silica in radionuclide chelation.

关键词: magnetic nanoparticle     3D mesoporous silica     amino functionalization     adsorption of U(VI)     acid resistance    

Enhanced performances in catalytic oxidation of

Nanli QIAO,Xin ZHANG,Chi HE,Yang LI,Zhongshen ZHANG,Jie CHENG,Zhengping HAO

《环境科学与工程前沿(英文)》 2016年 第10卷 第3期   页码 458-466 doi: 10.1007/s11783-015-0802-1

摘要: A series of hierarchical macro-/mesoporous silica supports (MMSs) were successfully synthesized using dual-templating technique employing polystyrene (PS) spheres and the Pluronic P123 surfactant. Pd was next loaded on the hierarchical silica supports via colloids precipitation method. Physicochemical properties of the synthesized samples were characterized by various techniques and all catalysts were tested for the total oxidation of -xylene. Among them, the Pd/MMS-b catalyst with tetraethoxysilane/polystyrene weight ratio of 1.0 exhibited superior catalytic activity, and under a higher gas hourly space velocity (GHSV) of 70000 h , the 90% conversion of -xylene has been obtained at around 200°C. The BET and SEM results indicated that Pd/MMS-b catalyst possesses high surface area and large pore volume, and well-ordered, interconnected macropores and 2D hexagonally mesopores hybrid network. This novel ordered hierarchical porous structure was highly beneficial to the dispersion of active sites Pd nanoparticles with less aggregation, and facilitates diffusion of reactants and products. Furthermore, the Pd/MMS-b catalyst possessed good stability and durability.

关键词: hierarchical macro-/mesoporous     silica     palladium     VOCs catalytic oxidation    

Optimizing the compressive strength of concrete containing micro-silica, nano-silica, and polypropylene

Fatemeh ZAHIRI, Hamid ESKANDARI-NADDAF

《结构与土木工程前沿(英文)》 2019年 第13卷 第4期   页码 821-830 doi: 10.1007/s11709-019-0518-6

摘要: Many studies have evaluated the effects of additives such as nano-silica (NS), micro-silica (MS) and polymer fibers on optimizing the mechanical properties of concrete, such as compressive strength. Nowadays, with progress in cement industry provides, it has become possible to produce cement type I with strength classes of 32.5, 42.5, and 52.5 MPa. On the one hand, the microstructure of cement has changed, and modified by NS, MS, and polymers; therefore it is very important to determine the optimal percentage of each additives for those CSCs. In this study, 12 mix designs containing different percentages of MS, NS, and polymer fibers in three cement strength classes(CSCs) (32.5, 42.5, and 52.5 MPa) were designed and constructed based on the mixture method. Results indicated the sensitivity of each CSCs can be different on the NS or MS in compressive strength of concrete. Consequently, strength classes have a significant effect on the amount of MS and NS in mix design of concrete. While, polymer fibers don’t have significant effect in compressive strength considering CSCs.

关键词: mixture method     compressive strength     nano-silica     micro-silica     polypropylene fibers    

Review on research and application of mesoporous transitional metal oxides in water treatment

Minghao SUI, Lei SHE

《环境科学与工程前沿(英文)》 2013年 第7卷 第6期   页码 795-802 doi: 10.1007/s11783-013-0521-4

摘要: This paper reviews the application of mesoporous transitional metal oxides in water treatment on basis of the catalysis and adsorption. Mesoporous transitional metal oxides are characterized by their intrinsic features, such as a high surface area, a highly ordered array of unidimensional pores with a very narrow pore size distribution, and highly dispersed active sites. Finally, the suggestions of further study on application are proposed.

关键词: mesoporous materials     transitional metal oxides     catalysis     adsorption     water treatment    

Dispersion of “guava-like” silica/polyacrylate nanocomposite particles in polyacrylate matrix

QI Dongming, YANG Lei, WU Minghua, SHAO Jianzhong, BAO Yongzhong

《化学科学与工程前沿(英文)》 2008年 第2卷 第2期   页码 127-134 doi: 10.1007/s11705-008-0033-0

摘要: A series of “guava-like” silica/polyacrylate nanocomposite particles with close silica content and different grafting degrees were prepared via mini-emulsion polymerization using 3-(trimethoxysilyl)propyl methacrylate (TSPM) modified silica/acrylate dispersion. The silica/polyacrylate composite particles were melt-mixed with unfilled polyacrylate (PA) resin to prepare corresponding silica/polyacrylate molded composites and the dispersion mechanism of these silica particles from the “guava-like” composite particles into polyacrylate matrix was studied. It was calculated that about 110 silica particles were accumulated in the bulk of every silica/polyacrylate composite latex particle. Both the solubility tests of silica/polyacrylate composite latex particles in tetrahydrofuran (THF) and the section transmission electron microscope (TEM) micrographs of silica/polyacrylate molded composites indicated that the grafting degree of silica particles played a crucial role in the dispersion of silica/polyacrylate composite particles into the polyacrylate matrix. When the grafting degree of polyacrylate onto silica was in a moderate range (ca. 20%–70%), almost all of silica particles in these “guava-like” composite particles were dispersed into the polyacrylate matrix in a primary-particle-level. However, at a lower grafting degree, massive silica aggregations were found in molded composites because of the lack of steric protection. At a greater grafting degree (i.e., 200%), a cross-linked network was formed in the silica/polyacrylate composite particles, which prevented the dispersion of composite particles in THF and polyacrylate matrix as primary particles.

关键词: silica/polyacrylate composite     cross-linked network     –70     guava-like     TEM    

Ti incorporation in MCM-41 mesoporous molecular sieves using hydrothermal synthesis

Shengping WANG, Changqing MA, Yun SHI, Xinbin MA

《化学科学与工程前沿(英文)》 2014年 第8卷 第1期   页码 95-103 doi: 10.1007/s11705-014-1405-2

摘要: Titanium-containing mesoporous materials (Ti-MCM-41) were obtained by hydrothermal synthesis. Such materials are active catalysts for the transesterification of dimethyl oxalate and phenol to produce diphenyl oxalate. To understand the role of the Ti in the catalytic process, Ti-MCM-41 samples with different Si/Ti ratios (from 5 to 100) were prepared and the samples were analyzed by Fourier transform infrared spectroscopy, UV-visible spectroscopy, and ammonia temperature programmed desorption. It was concluded that the Ti is incorporated into the framework of the MCM-41 and formed weak Lewis acid sites. In addition, the number of Ti(IV) sites increased as the amount of titanium increased. X-ray powder diffraction, N adsorption-desorption and transmission electron microscopy results showed that the Ti-MCM-41 samples have a hexagonal arrangement of mono-dimensional pores. A large number of Ti(IV) sites coupled with the mesoporous structure and large pore diameters are favorable for the transesterification catalytic properties of Ti-MCM-41.

关键词: Ti-MCM-41     mesoporous molecular sieve     acid sites     transesterification     hydrothermal synthesis    

标题 作者 时间 类型 操作

Enhanced activation of persulfate using mesoporous silica spheres augmented Cu–Al bimetallic oxide particles

期刊论文

The modification of titanium in mesoporous silica for Co-based Fischer–Tropsch catalysts

期刊论文

Sulfonic acid-functionalized mesoporous silica catalyst with different morphology for biodiesel production

期刊论文

Synthesis of ordered cerium-doped cubic mesoporous silica using long-chain ionic liquid as template

YUE Hongxia, ZHAO Hongmei, LIU Longjiang, WANG Siping, Ruan Qiong, WANG Tongwen

期刊论文

Enhanced Fenton-like process over Cu/L(+)-ascorbic acid co-doping mesoporous silica for toxicity reduction

期刊论文

Fe3O4 encapsulated mesoporous silica nanospheres with tunable size and large void

Tingting LIU, Lihong LIU, Jian LIU, Shaomin LIU, Shi Zhang QIAO

期刊论文

Surface modification of mesoporous silica nanoparticle with 4-triethoxysilylaniline to enhance seawater

Jian Wang, Qun Wang, Xueli Gao, Xinxia Tian, Yangyang Wei, Zhen Cao, Chungang Guo, Huifeng Zhang, Zhun Ma, Yushan Zhang

期刊论文

Crystalline mesoporous transition metal oxides: hard-templating synthesis and application in environmental

Zhen MA, Bei ZHOU, Yu REN

期刊论文

Fabrication of bimetallic Cu–Zn adsorbents with high dispersion by using confined space for gas adsorptive separation

期刊论文

Magnetic KIT-6 nano-composite and its amino derivatives as convenient adsorbent for U(VI) sequestration

期刊论文

Enhanced performances in catalytic oxidation of

Nanli QIAO,Xin ZHANG,Chi HE,Yang LI,Zhongshen ZHANG,Jie CHENG,Zhengping HAO

期刊论文

Optimizing the compressive strength of concrete containing micro-silica, nano-silica, and polypropylene

Fatemeh ZAHIRI, Hamid ESKANDARI-NADDAF

期刊论文

Review on research and application of mesoporous transitional metal oxides in water treatment

Minghao SUI, Lei SHE

期刊论文

Dispersion of “guava-like” silica/polyacrylate nanocomposite particles in polyacrylate matrix

QI Dongming, YANG Lei, WU Minghua, SHAO Jianzhong, BAO Yongzhong

期刊论文

Ti incorporation in MCM-41 mesoporous molecular sieves using hydrothermal synthesis

Shengping WANG, Changqing MA, Yun SHI, Xinbin MA

期刊论文