Materials
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2022
·Vol. 15
·期 8
·2780
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IF 3.748
Xuzhao Yang,Yarong Bai,Qing Li,Jun Wang
A mesoporous molecular sieve was prepared by the hydrothermal synthesis method with symmetric Gemini surfactant 1,3-bis(hexadecyldimethylammonio)-propane dibromide, symmetric Gemini ionic liquid surfactant 1,3-bis(3-hexadecylimidazolium-1-yl) propane dibromide and self-designed asymmetric Gemini ionic liquid surfactant 1-(3-(hexadecyldimethylammonio)prop-1-yl)-3-hexadecylimidazolium dibromide as the template agent. The structure characterization results for mesoporous molecular sieves show that the material possesses a hexagonal pore structure with uniform channels. The mesoporous silica that was synthesized with self-designed asymmetric Gemini ionic liquid surfactant as the template agent possesses the largest surface area and its pore size and specific surface area are, respectively, 3.28 nm and 879.37 m2/g. The adsorption properties of the prepared MCM-41 for crystal violet were investigated, and the adsorption thermodynamics and kinetics were investigated. The results show that adsorption equilibrium can be reached under pH = 9 and 35 °C for 50 min, and the quantity of adsorption can reach up to 464.21 mg/g. The adsorption process belongs to Langmuir isothermal adsorption, conforming to second-order adsorption kinetics, and the adsorption process is an endothermic process.Keywords:Gemini ionic liquid surfactants;mesoporous molecular sieves;crystal violet;thermodynamics;kinetics
研究领域:
材料科学
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化学工程
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环境化学
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产品关联
DOI
PubMed
高影响因子
Royal Society Open Science
·
2022
·Vol. 9
·期 11
·
IF 3.653
Jiangyi Yan,Yuting Cai,Rong Xu,Beifu Wang,Lihong Nie
The ability of membranes to separate oil vapour is affected by their permeance and selectivity. This study modifies polyether block amide (PEBA) composite membranes with a microporous zeolite, Silicalite-1, or a mesoporous zeolite, MCM-41. The results show that when PEBA composite membranes are modified with these zeolites, the selective layer of the composite membrane is coated more thinly, resulting in a higher flux of organic gas. Silicalite-1 increases the hydrophobicity of the membrane, which facilitates the adsorption of organic vapour on the membrane surface, thus improving the membrane selectivity. In the separation of oil vapour, both modified membranes can effectively increase the gas permeabilities and selectivities. The main mechanism governing gas transport in the MCM-41-modified membrane is Knudsen diffusion, so the selectivity for small molecules is improved more significantly. By contrast, the dissolution–diffusion mechanism is dominant in the Silicalite-1-modified membranes, which considerably increases the selectivity for large molecules.
研究领域:
材料科学
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化学工程
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膜技术
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DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
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2019
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IF 7.65
Peng Liao,Binrui Li,Lin Xie,Xiaoao Bai,Han Qiao,Qianqian Li,Biwei Yang,Chongxuan Liu
Engineered nanoparticles-mediated contaminant transport has been recognized as a significant process governing the mobility of metals and radionuclides in groundwater. Engineered silicate nanoparticles (ESNPs) are attractive materials for the sequestration or extraction of Cr(VI) and other metals and radionuclides from groundwater. While great efforts have been devoted toward the application of these materials for Cr(VI) sequestration, the underlying interface adsorption mechanism is not thoroughly elucidated. This study investigates the immobilization mechanisms of Cr(VI) on a representative ESNPs, NH 2 -MCM-41, over a range of water chemistry conditions. By combining batch adsorption experiments with an array of complementary characterizations, we provided spectroscopic and microscopic evidence that the electrostatic interactions between the positively charged NH 2 -MCM-41 surface derived from amino functionality and the negatively charged Cr(VI) species was the dominant mechanism responsible for Cr(VI) immobilization. In addition, the weak hydrogen bonding interactions may also contribute to adsorption to a degree. Furthermore, thermodynamic studies suggested a favorable, spontaneous, and exothermic adsorption process. Site energy analysis illustrated that the distribution of energy binding sites on NH 2 -MCM-41 is Cr(VI) loading dependent. The new insights provided here can advance understanding of the transport of Cr(VI) associated NH 2 -MCM-41 that benefits the application of ESNPs-based technologies for metals immobilization in groundwater.
研究领域:
环境科学
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纳米技术
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污染治理
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DOI
PubMed
高影响因子
INDUSTRIAL CROPS AND PRODUCTS
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2023
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IF 5.9
Xiaoxuan Ma,Tianyang Guo,Peng Fu,Zhiyu Li,Kaiwei Sun,Liang Zheng,Huiyan Zhang
Aromatic hydrocarbons (AHs) production from in-situ catalytic co-pyrolysis (CCP) of biomass and plastics is a promising technology. However, the combined effects of the mixing mode and proportion of raw materials in catalytic co-pyrolysis and the double-size effect of micro-mesoporous core-shell catalysts on AHs production remain questionable. The formation characteristics and mechanism of AHs in CCP process were studied from mass transfer and free radial direction. The results showed that the yield of BTEX (benzene, toluene, ethylbenzene, and xylene) was 20.44 wt% when the mass ratio of cellulose/polyethylene/cellulose (C-P-C) was 0.5:1:0.5 at 500 ℃. The free radicals generated during the breaking of polyethylene bonds can promote the transfer of hydrogen atoms to cellulose pyrolysis intermediates, which results in mass transfer effect. The C-P-C loading mode makes hydrogen atoms always pass through the cellulose without escaping, and the increase of polyethylene ratio makes the number of hydrogen free radicals increase significantly, both of which jointly regulate the hydrogen free radical mass transfer efficiency. However, the high concentration of hydrogen free radicals can quench the pyrolysis of cellulose. The conjugated double size effect of ZSM-5 @MCM-41 leads to their greater catalytic capacity for free radical carrying co-pyrolysis products compared to ZSM-5. With the increase of mesoporous shell, the yield of BTEX increases first and then decreases, but the yield of coke is opposite. The BTEX yield of 1.0SH-Z5 @ M41 is 3.15 times that of ZSM-5, and the coke yield is only 14.70% that of ZSM-5. The reaction pathway of promoting cellulose pyrolysis by polyethylene and the mechanism of hydrogen free radical - mass transfer co-pyrolysis involved were put forward.
研究领域:
能源与环境科学
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催化化学
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产品关联
DOI
高影响因子
KINETICS AND CATALYSIS
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2023
·Vol. 64
·期 6
·909-921
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IF 1.1
Li Linbo,Du Yijun,Li Yao,Shao Linjun,Qi Chenze,Zhou Shujing,Li Jinjing
Abstract Developing a facile and accurate method for assessing catalytic activities of supported metals can significantly promote the preparation and application of supported metal catalysts. Herein, we synthesized five MCM-41 materials functionalized with Schiff-base groups, which were employed as the supports for copper cations. The chemical structures and coordination of copper cations on the supports were characterized by Fourier-transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS). The grafting densities were calculated by analyzing the results of thermal gravimetric analysis (TGA) and elemental analysis (EA). The microstructures of these supported copper catalysts were analyzed by transmission electron microscopy (TEM) and X-ray diffraction (XRD). The oxidation of thioanisole to methylphenyl sulfoxide was employed to determine the catalytic activities of these supported copper catalysts while their o -Ps annihilation properties were evaluated by the positron annihilation lifetime spectroscopy. It is found that the o -Ps annihilation properties were linearly correlated with their catalytic activities. Therefore, the catalytic activities of supported copper species surrounded by different functional groups can be easily determined through o -Ps annihilation.
研究领域:
化学
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催化科学
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材料科学
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DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2020
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IF 5.774
Xiao Zhang,Bin Ren,Yanhua Xu,Xi Li,Peng Yu,Yongjun Sun,Huaili Zheng
Mn/MCM-41 and imp-Mn/MCM-41 catalysts were prepared in this study through metal heteroatom substitution and impregnation methods, respectively, and their catalytic oxidation performance of toluene under non-thermal plasma (NTP) in a dielectric barrier discharge reactor was studied. The stability of the catalyst and the parameters of catalytic oxidation conditions (initial concentration of toluene, O 2 ratio, and relative humidity of carrier gas) were optimized. Characterization proved that the impregnation method resulted in the existence of manganese in the form of oxides (MnO 2 , Mn 2 O 3 ) outside the pores of MCM-41. Meanwhile, the metal heteroatom substitution method implanted manganese into the mesoporous structure and replaced part of it with Si-O-Mn. NTP catalytic oxidation of toluene, ozone emission, and GC–MS by-product analysis confirmed that 60Mn/MCM-41 catalyst has high catalytic activity. Moreover, the catalyst affected the production of by-products. The stability test revealed that the 60Mn/MCM-41 catalyst still respectively reached 84.6% and 61% in the conversion of toluene and the selectivity of CO 2 under the SED of 558 J/L after 40 h discharge reaction.
研究领域:
环境科学
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催化化学
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产品关联
DOI
高影响因子
CATALYSIS COMMUNICATIONS
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2013
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IF 2.915
Songbai Qiu,Xue Zhang,Qiying Liu,Tiejun Wang,Qi Zhang,Longlong Ma
A simple method for preparing highly active and dispersed supported metal catalysts was developed by co-impregnation. Compared with conventional wetness impregnation, addition of moderate ethylene glycol into the metal nitrate aqueous solution could enhance interaction with MCM-41 surface, resulting in formation of very small NiO particle size (3.5 nm) and high dispersion of the active phase. The Ni/MCM-41 catalysts using co-impregnation exhibited excellent catalytic performance for low temperature hydrogenation of naphthalene with 100% conversion at 55 °C, which could rival the activity of commercial Raney Ni catalyst. The obtained catalysts were characterized by XRD, TEM, TG-DSC, FT-IR, BET and TPR.
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DOI
高影响因子
PROGRESS IN REACTION KINETICS AND MECHANISM
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2019
·
IF 0.582
Jiaojing Zhang,Hua Song,Yanguang Chen,Tianzhen Hao,Feng Li,Dandan Yuan,Xueqin Wang,Liang Zhao,Jinsen Gao
A series of APTMS ((3-aminopropyl)trimethoxysilane)-modified silicate MCM-41 adsorbents (x-APTMS/MCM-41, x is the volume of APTMS per 1 g of silicate MCM-41) with different APTMS contents was prepared, and the effects of APTMS content on the desulfurization performance of the APTMS/MCM-41 adsorbents were studied in a fixed adsorption bed using H2S and N2 mixture as a model gas. The as-prepared adsorbents were characterized by X-ray diffraction analysis, N2 adsorption–desorption, Fourier transform infrared spectroscopy, transmission electron microscopy, scanning electron microscopy, and energy-dispersive spectroscopy. The results showed that all the APTMS-modified x-APTMS/MCM-41 adsorbents retained the mesoporous silica structure of MCM-41. The Brunauer–Emmett–Teller-specific surface area of x-APTMS/MCM-41 increased slightly with increasing x at first and then decreased with further increasing APTMS content. The H2S removal performances of x-APTMS/MCM-41 adsorbents decreased in the order 0.6-APTMS/MCM-41 > 0.7-APTMS/MCM-41 > 0.5-APTMS/MCM-41 > 0.4-APTMS/MCM-41 > 0.8-APTMS/MCM-41. At x = 0.6, the maximum H2S removal rate of 54.2% and H2S saturated capacity of 134.4 mg g−1 were observed. The regeneration experiment of 0.6-APTMS/MCM-41 adsorbent after three times regeneration at 423 K for 3 h in nitrogen confirmed that it possessed a good regenerability.
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DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2026
·
IF 5.1
Wenlong Gao,Jinpeng Wei,Yonggang Sun,Yuyu Wang,Feng Lin,Yulong Ma
A composite catalyst that combines acid and metal catalysis has been developed. • Selectivity of up to 83.12 % toward MAHs achieved in lignin pyrolysis. • Heating rate affects routes and activation energy in catalytic lignin conversion. • SiW affords B acid sites while Ni centers stabilize intermediates and inhibit coking. To address the challenges of complex deoxygenation pathways and low monoaromatic hydrocarbon (MAHs) selectivity in the catalytic conversion of lignin, a series of SiW/Ni-MCM-41 metal–acid bifunctional catalysts were synthesized via an incipient wetness impregnation method. The effects of silicotungstic acid (SiW) loading ratios on the physicochemical properties of the catalysts and their performance in lignin catalytic pyrolysis were systematically investigated. Characterization results revealed that both SiW and Ni species were highly dispersed on the surface of the MCM-41 support, with interactions between them. With increasing SiW loading, specific surface area and pore volume decreased, Brønsted acid proportion increased, and total acid sites decreased mainly due to Lewis acid loss, enabling Brønsted/Lewis acid balance tuning. Catalytic performance evaluation demonstrated that the catalyst with a SiW-to-Ni-MCM-41 mass ratio of 1:2 exhibited the optimal lignin conversion (80.25 %) and MAHs selectivity (83.12 %), alongside excellent universality in substrate extension experiments. Kinetic analysis indicated that the apparent activation energy is heating-program dependent. In-situ FTIR confirmed that the Brønsted acid sites provided by SiW promoted deoxygenation and alkylation reactions, the Ni metal centers assisted deoxygenation and stabilized the aromatic ring structure via hydrogen-transfer-related pathways, while inhibiting condensation and coking side reactions to a certain extent; and the mesoporous MCM-41 framework provided a highly dispersed environment and a possible confinement-like effect, collectively driving the efficient conversion of lignin into monoaromatic hydrocarbons. This study provides a novel design strategy for metal–acid synergistic catalysts in the field of high-value conversion of lignin. Download: Download high-res image (144KB) Download: Download full-size image
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DOI
高影响因子
ENVIRONMENTAL RESEARCH
·
2026
·
IF 8.2
Zhouxiao Zhai,Jingce Bi,Linshan Wang,Ningning Liu,Yi Wang,Xia Zhang,Zhuopeng Wang,Yide Han
Mesoporous molecular sieve-supported metals have been widely investigated as catalysts for the removal of tetracycline (TC) from water via a “preconcentration-activation-degradation” catalytic system. However, the design and construction of bimetallic catalysts supported on MCM-41 for TC degradation remains a challeng. In this study, highly dispersed Al-Fe 3 N species within MCM-41(Al-Fe 3 N/Al-MCM-41) was successfully prepared, where Al originates from Al-MCM-41 subjected to high-temperature dealumination. In the presence of Al-Fe 3 N/Al-MCM-41 and PDS, 98.5% of TC was efficiently degraded within 60 min. The corresponding reaction rate constant (0.07262 min −1 ) was 2.92 times that of Fe 3 N/MCM-41 (0.02486 min −1 ). The excellent degradation performance is attributed to the enhanced electron cloud density of Fe induced by Al doping, thereby enhancing the activation efficiency of peroxydisulfate (PDS). At the same time, micro–mesoporous structure in Al-Fe 3 N/Al-MCM-41 is beneficial to preconcentration of target contaminants for the enhancement of degradation efficiency. In addition, the disinfection performance of Al-Fe 3 N/Al-MCM-41 system against antibiotic-resistant bacteria and its device-level application were explored. This work provides a novel strategy to fabricate MCM-41 with doping Fe 3 N species for the water treatment. This strategy provides a new perspective for the rational utilization of Al atoms via high-temperature dealumination method.
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DOI
PubMed
高影响因子
JOURNAL OF CHROMATOGRAPHY A
·
2020
·
IF 4.049
Wenli Zhu,Jing Zhang,Xiaowan Zhang,Lizhen Han,Peige Qin,Shufang Tian,Qian Zhou,Xuebin Zhang,Minghua Lu
The Al-doped mesoporous crystalline material-41 (Al-MCM-41) composite was prepared and applied as fiber coating material of headspace solid-phase microextraction (HS-SPME) for extraction of polycyclic aromatic hydrocarbons (PAHs) from human urine. Five PAHs including acenaphthene, fluorene, phenanthrene, anthracene, and pyrene are chosen as target analytes to evaluate the performance of the material by GC-FID analysis. The mesoporous Al-MCM-41 composite was characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, nitrogen adsorption/desorption measurement, and thermogravimetric analysis. The parameters affecting the extraction efficiency of HS-SPME were investigated. Under the optimal conditions, the method exhibits ideal linearity for target analytes in the range of 0.3–600 ng⋅mL -1 with the coefficients (R 2 ) equal or higher than 0.9906. The enrichment factors are calculated from 540 to 1760. The limits of detection (LODs) and limits of quantitation (LOQs) are between the ranges of 0.06–0.18 and 0.3–0.9 ng⋅mL -1 , respectively. The relative standard deviations (RSDs) ( n = 5) of intra-day and inter-day are in the ranges of 1.08–7.49% and 2.84–18.3% respectively. The fiber-to-fiber reproducibility ( n = 3) is in the range of 6.47–13.9%. The method was successfully applied for the analysis of PAHs in human urine with reasonable recoveries which is ranging from 73.29 to 116.1%.
研究领域:
分析化学
·
环境科学
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DOI
高影响因子
JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY
·
2024
·Vol. 333
·期 3
·1343-1356
·
IF 1.5
Bi Dongxu,Cai Weiqian,Xiong Lingshan,Luo Qie,Wang Youqun,Zhang Zhibin,Xu Lin,Cao Xiaohong,Liu Yunhai
Three types of magnetic mesoporous silicas (MMSs), namely, MMCM-41, MMCM-48 and MSBA-15 were prepared by a hydrothermal method using CTAB and P123 as templates. The structure and physicochemical properties of MMSs were characterized by small angle XRD, VSM, ζ potential analyzer, contact angle measurer, and XPS, etc. The potential applications of MMSs in U(VI) recovery were thoroughly investigated. The adsorptive kinetics, thermodynamics, and selectivity of MMCM-41, MMCM-48 and MSBA-15 were compared. The results show that MSBA-15 revealed a high capacity for U(VI) (341.94 mg·g −1 ) and a superior selectivity than MMCM-41 and MMCM-48. The adsorption mechanism was explored by using the relevant adsorption models and XPS. The results indicated that MSBA-15 could be considered a strong candidate for the adsorption and recovery of U(VI) from radioactive wastewater.
研究领域:
环境科学
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材料科学
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化学工程
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核技术
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DOI
高影响因子
危险品化学品经营许可证（带存储）