JOURNAL OF HAZARDOUS MATERIALS
·
2023
·
IF 13.6
Xukai Li,Weirui Chen,Dongpo Liu,Gaozu Liao,Jing Wang,Yiming Tang,Laisheng Li
Due to its low interfacial electron migration ability and highly hydrophilic, Fe-MCM-41 (FeM) had poor activity and stability during catalytic ozonation . To this end, the secondary metal Zn and Si-F group were introduced into the framework of FeM to create surface potential difference and hydrophobic sites. Comparative characterizations showed that there existed rich acid sites with great potential difference on F-Fe-Zn-MCM-41 (FFeZnM). Additionally, because of the existence of hydrophobic and electron-withdrawing Si-F unit, the electron migration ability, hydrophobicity and acidity of FFeZnM were enhanced. The greater O 3 mass transfer was induced by Si-F group and O 3 was directly activated at Fe and Zn Lewis acid sites into •OH, •O 2 - and 1 O 2 . With •OH acting as main species, FFeZnM/O 3 achieved the superior IBP removal (93.4%, 30 min) and TOC removal (46.6%, 120 min) over those of sole O 3 and F-FeM/O 3 processes, respectively. HCO 3 - , Cl - , NO 3 - and SO 4 2- hindered IBP degradation by FFeZnM/O 3 , but high concentration humic acid (HA) exhibited promotion by forming HA-IBP complex. IBP degradation by FFeZnM/O 3 was enhanced with tap water , river water, and effluent from the secondary sedimentation tank of the sewage plant acting as medium. This study proposed an innovative approach to catalyst design for catalytic ozonation.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
RENEWABLE ENERGY
·
2024
·
IF 9
Siqi Lv,Rui Zhang,Yuanping He,Zichuan Ma,Xiaolong Ma
Volatile methyl siloxanes (VMSs), which are converted to silica sediments during biogas burning, are regarded as the most problematic VMSs in existing biogas cleaning systems. However, the majority of methods for VMS removal, including cryogenic condensation, physical absorption, chemical absorption and porous material adsorption have been constrained by these methods' intrinsic drawbacks. Here, we present an alternate method for removing VMS from gas streams that are based on the materials supported by H 2 SO 4 . Simple incipient wetness impregnation was used to create MCM-41-supported H 2 SO 4 (SSA/MCM) materials, which showed high reactive adsorption property for hexamethyldisiloxane (L2) elimination in the temperature range of 80–160 °C with the peak reactivity at 100 °C. With maximum Q B and Q m values of 191.3 and 365.6 mg g −1 , respectively, dynamic adsorption findings showed the significance of altering the intake concentration, gas flow rate, adsorbent mass, relative humidity, as well as H 2 SO 4 loading in determining the L2 removal efficacy. Furthermore, it was established that the L2 reactive adsorption was caused by the polymerization of L2 by supported H 2 SO 4 , which produced the creation of polysiloxane. The findings offer an important foundation for creating a cutting-edge biogas cleaning method.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2019
·Vol. 9
·期 37
·21473-21477
·
IF 3.049
Qianfan Yang,Jiasheng Wang,Wan-Hui Wang,Ming Bao
Subnano MoO3/MCM-41 was successfully prepared through doping (NH4)6Mo7O24 in the synthesis process of MCM-41. The morphology of MoO3/MCM-41 was visually observed by TEM and HADDF-STEM. N2 sorption, XPS and Raman were further applied to investigate the structure of the material. MoO3/MCM-41 was used in the oxidative desulfurization process with tert-butyl hydroperoxide as oxidant. MoO3/MCM-41 showed outstanding catalytic activity and recycling ability at room temperature.
研究领域:
材料科学
·
环境化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ENERGY & FUELS
·
2020
·
IF 3.421
Cui-Ping Ye,Rui-Nan Wang,Xia Gao,Wen-Ying Li
To screen the efficient media for CO2 capture of flue gas from power plants, a strategy for improving the CO2 capture capacity by dual functionalized ionic liquids (ILs) with multiple active sites is proposed. Three phosphonium dual functionalized ILs ([aP4443][2-Np], [aP4443][2-Op], and [aP4443][Triz]) have been prepared. The sorption capacities of the synthesized ILs under pure CO2 atmosphere and the supported ILs under different loading amounts from 10 to 50%, temperatures of 30–80 °C, and CO2 partial pressure varied from 10 to 15% were determined. Fourier transform infrared (FTIR) spectroscopy was applied to reveal the interaction between CO2 and ILs, and the pseudo-second-order model and the intraparticle diffusion model were used for a better understanding of the CO2 adsorption behavior. The results showed that a high capacity up to 1.88 mol of CO2/mol of IL for [aP4443][2-Np] is achieved, and 30% IL–MCM-41 can reach 3.19 mmol/g with excellent reversibility under the atmosphere of CO2:N2 (15%:85%) at 30 °C and 0.1 MPa. Raising the temperature or decreasing the CO2 concentration is not conducive to improving the CO2 capacity. FTIR spectroscopy demonstrated that the amino and hydroxyl react with CO2 to form NHCOO– or CO3–. Combined with the activation energy calculation, the kinetic analysis revealed that the CO2 capture of supported ILs is an internal diffusion controlled physical adsorption.
研究领域:
化学工程
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
ChemistrySelect
·
2024
·Vol. 9
·期 9
·e202302529
·
IF 1.9
Mingyue Piao,Xue Peng,Hao Liu,Wei Zhang,Honghui Teng
Graphical nZVI/MCM-41/rGO is designed for improving the properties of nZVI, and the results show that it has an apparent Fe(0) crystallinity and modest rGO crystallinity, as well as a rough and porous structure. There are many oxygen-containing groups found on the surface of nZVI/MCM-41/rGO, such as −OH, −COOH, and Si−O. The pore diameter is concentrated at 23.82 nm, and the specific surface area is 15.94 cm 2 /g. The best performance is occurred at pH 6, C 0 =80 mg/L with a 2 g/L adsorbent dosage, and after 180 min, a maximum adsorption capacity of 41.82 mg/g is reached at 333 K. The Dubinin-Radushkevich isotherm and second order kinetic models fit the Ni(II) adsorption process well. It is determined through analysis of the thermodynamic parameters that the adsorption progress is endothermic (ΔH 0 >0) and spontaneous (ΔG 0 <0). nZVI/MCM-41/rGO has proven to be an effective and alternative material for the removal of Ni(II) ions from aqueous media due to its excellent removal ability, availability, and low cost. Emissions of nickel (Ni) are harmful to the environment and people‘s health. Although nano zero-valent iron (nZVI) has a lot of potential for treating water pollution, its instability and tendency for aggregation have limited its application. In order to improve its properties, composite adsorbent MCM-41/rGO supported nZVI (nZVI/MCM-41/rGO) is designed for improving the properties of nZVI, and it is characterized by SEM, XRD, FTIR and BET. The results show that it has an apparent Fe (0) crystallinity and modest rGO crystallinity, as well as a rough and porous structure. There are many oxygen-containing groups found on the surface of nZVI/MCM-41/rGO, such as −OH, −COOH, and Si−O. The pore diameter is concentrated at 23.82 nm, and the specific surface area is 15.94 cm 2 /g. The consequences of several parameters such as contact time, initial metal ion concentration, adsorbent dosage, and pH for adsorption efficiency were investigated. The best performance is occurred at pH 6, C 0 =80 mg/L with a 2 g/L adsorbent dosage, and after 180 min, a maximum adsorption capacity of 41.82 mg/g is reached at 333 K. The Dubinin-Radushkevich isotherm and second order kinetic models fit the Ni(II) adsorption process well. It is determined through analysis of the thermodynamic parameters that the adsorption progress is endothermic ( ΔH 0 >0) and spontaneous ( ΔG 0 <0). nZVI/MCM-41/rGO has proven to be an effective and alternative material for the removal of Ni(II) ions from aqueous media due to its excellent removal ability, availability, and low cost.
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
CHEMICAL ENGINEERING JOURNAL
·
2016
·
IF 5.31
Guan-Yu Pan,Yu-Long Ma,Xiao-Xia Ma,Yong-Gang Sun,Jun-Min Lv,Jian-Li Zhang
Ni–W/MCM-41 as a non-noble metal catalyst for catalytic conversion of corn stalk pretreated with alkali into polyol was prepared by an impregnation method. The results showed that pretreatment corn stalk with alkali removed 41.79 wt% of hemicellulose and 60.21 wt% of lignin and thereby increased the content of cellulose from 41.13 wt% to 59.29 wt%. Data obtained from X-ray photoelectron spectra exhibited that there was an intense interaction between nickel and tungsten. Meanwhile, the Ni 17 W 3 alloy was evidenced by X-ray diffraction spectra. These were very beneficial to enhance the catalytic conversion of lignocellulose into polyol. The maximum yield of 71.37 wt% polyol was obtained by catalytic hydrogenation of lignocellulose to ethylene glycol and 1,2-propylene glycol utilizing 5%Ni–15%W/MCM-41 catalyst under H 2 pressure of 6 MPa and 250 °C for 2 h.
研究领域:
生物化学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
ENERGY & FUELS
·
2018
·
IF 3.024
Na Rao,Mei Wang,Ziming Shang,Yanwen Hou,Guozhi Fan,Jianfen Li
Modifications by impregnation and grafting are commonly used for the preparation of amine-functionalized MCM-41. A comprehensive evaluation of the advantages and disadvantages of the two methods was performed in this work. MCM-41 was synthesized by the hydrothermal method, setting the amine-loading mass fraction at 40, 50, and 60 wt %. Three amine-modified adsorbents were prepared by impregnating polyethylenimine (PEI), and the three other adsorbents were prepared by grafting 3-aminopropyltriethoxysilane (APTS) onto MCM-41. The as-prepared adsorbents were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, thermogravimetric analysis, and N2 adsorption–desorption techniques. CO2 adsorption capacities were measured, and the experimental data were fitted with adsorption kinetic models. The cyclic stability of the adsorbents prepared by the two kinds of amine-modified methods was compared using the cyclic adsorption–desorption experiments. The characterization results showed that the target adsorbents were prepared successfully. The thermal stability of the adsorbents modified by grafting was better than the thermal stability of the adsorbents modified by the impregnation. Maximum CO2 adsorption capacities of 3.53 mmol g–1 (50% PEI–MCM-41) and 2.41 mmol g–1 (50% APTS–MCM-41) could be reached at 25 °C and 1 atm, which were 4.7 and 3.2 times greater than that of MCM-41. The Avrami model fitted the experimental data well, indicating a variety of interactions between the adsorbents and CO2. CO2 adsorption capacity after 5 adsorption–desorption cycles decreased by 14.22 and 5.19% for the adsorbents prepared by impregnation and grafting, respectively. It was concluded that MCM-41 modified by impregnation and grafting followed the same kinetic model. The absorbents modified by impregnation showed higher CO2 adsorption capacity and amine-loading efficiency, while those prepared by grafting had better thermal and cyclic stabilities.
研究领域:
材料科学
·
环境科学
✓ 已验证
DOI
高影响因子
CHINESE JOURNAL OF CATALYSIS
·
2019
·
IF 4.914
Jingqing Tian,Haocheng Li,Xin Zeng,Zichun Wang,Jun Huang,Chen Zhao
ABSTRACT Development of dry reforming of methane and carbon dioxide is an effective route to convert in-dustrial waste gases such as coke-oven gas and coal-to-oil gas into platform syngas. However, this process encounters severe problems of metal particle sintering and coke formation at high tem-peratures. In this work, we developed a new synthetic method for preparing confined Ni/MCM-41 catalysts, which impede the sintering of metal nanoparticles (NPs) and coke deposition at high temperatures, enabling them to be successfully applied to methane dry reforming . The method results in high activity and stability of the catalyst at 700 °C for 200 h. The Ni precursor is immersed in ethanol and impregnated into MCM-41 by the peculiar capillary action of hexagonal straight mesopores . By this method, 10 wt% Ni NPs (d = 2 nm) is equably confined to the mesoporous channels with strong metal-support interactions, as confirmed by HRTEM, TEM mapping, H2-TPR, and XRD measurements. Such a confined structure has a significant effect on the inhibition of metal NP agglomeration and carbon deposition during methane dry reforming, as evidenced by TEM, Raman, TGA, and TPO measurements of used Ni/MCM-41 catalysts. In contrast, unconfined Ni/MCM-41 catalysts, with Ni NPs located on the pore exteriors, are rapidly deactivated after 12 h due to the blocked contact between the active metal centers and the gas feedstock. Additionally, a fast increase in the Ni NP size and the formation of substantial carbon nanotubes on the unconfined catalyst surface are seen. This work offers a facile approach for the synthesis of anti-sintering, car-bon-resistant confined Ni catalysts that can operate at high temperatures
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
FUEL
·
2022
·
IF 8.035
Ben Chen,Bowen Hui,Yuting Dong,Qiang Sheng,Xiang Li,Qinglan Hao,Chunjing Liu
The SiO 2 - and MCM-41-supported Ni catalysts were prepared by an incipient wetness impregnation method and their performance in the hydrogenation of liquid organic hydrogen carrier were evaluated using N-ethylcarbazole (NEC) as model compound. Ni particles were mainly located on the external surface of the SiO 2 -supported Ni catalysts. Both Ni particles on the external surface and filled in the mesopores of MCM-41 were found in the MCM-41-supported catalysts. The reduction of surface Ni particles occurred at low temperature (ca. 365 °C), but the complete reduction of Ni particles in the mesopores of MCM-41 required high temperature (ca. 555 °C). The MCM-41-supported Ni particles possessed lower electron densities than the SiO 2 -supported ones. The surface Ni particles showed the same activity in the hydrogenation of NEC, which were more active than those in the mesopores of MCM-41. A correlation between the electron density of Ni particles and their selectivity was observed. The higher the electron density of Ni particles, the higher the selectivity to the fully hydrogenated product (dodecahydro-N-ethylcarbazole) is.
研究领域:
催化
·
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Processes
·
2021
·Vol. 9
·期 2
·400
·
IF 2.847
Xiaohua Cao,Jichang Lu,Yutong Zhao,Rui Tian,Wenjun Zhang,Dedong He,Yongming Luo
Praseodymium (Pr)-promoted MCM-41 catalyst was investigated for the catalytic decomposition of methyl mercaptan (CH3SH). Various characterization techniques, such as X-ray diffraction (XRD), N2adsorption–desorption, temperature-programmed desorption of ammonia (NH3-TPD) and carbon dioxide (CO2-TPD), hydrogen temperature-programmed reduction (H2-TPR), and X-ray photoelectron spectrometer (XPS), were carried out to analyze the physicochemical properties of material. XPS characterization results showed that praseodymium was presented on the modified catalyst in the form of praseodymium oxide species, which can react with coke deposit to prolong the catalytic stability until 120 h. Meanwhile, the strong acid sites were proved to be the main active center over the 10% Pr/MCM-41 catalyst by NH3-TPD results during the catalytic elimination of methyl mercaptan. The possible reaction mechanism was proposed by analyzing the product distribution results. The final products were mainly small-molecule products, such as methane (CH4) and hydrogen sulfide (H2S). Dimethyl sulfide (CH3SCH3) was a reaction intermediate during the reaction. Therefore, this work contributes to the understanding of the reaction process of catalytic decomposition methyl mercaptan and the design of anti-carbon deposition catalysts.Keywords:rare earth;MCM-41;CH3SH decomposition;stability;reaction mechanism
研究领域:
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY
·
2016
·Vol. 310
·期 3
·1001-1011
·
IF 0.983
Xiao Jiang,Jing Yan,Yao Ying,Xie Shaolei,Wang Xingquan,Shi Chenglong,Jia Yongzhong
Herein, the amine-functionalized MCM-41 mesoporous silica (denoted as MCM-41-NH 2 ) was synthesized and applied to adsorption and recovery U(VI) ions from aqueous solutions. The results showed that the sorption of U(VI) on MCM-41-NH 2 was strongly dependent on pH and ionic strength. The sorption was mainly dominated by outer-sphere surface complexation and the sorption equilibrium can be reached within 60 min. The maximum sorption capacity of MCM-41-NH 2 for U(VI) was calculated to be 386.98 mg g −1 at pH 5.60, much higher than that of the other reported materials.
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
NEW JOURNAL OF CHEMISTRY
·
2020
·Vol. 44
·期 7
·2980-2985
·
IF 3.288
Zhen Li,Li Li,Huali Liu,Fei Li,Jiaqi Zhao,Yu Wang
Mn2+-doped CsPbBr3 nanocrystals (NCs) within MCM-41 mesophase silica have been prepared via a template-assisted strategy by using MCM-41 as the template. The template-synthesized CsPb1−xMnxBr3 NCs (x = 0–1) with the investigated perovskite compositions are luminescent with 465 nm pure blue light. The coprecipitation of bulk materials can be controlled by varying the amount of Mn2+ doping because the formation energy of CsPbBr3 NCs rises slightly on increasing the Mn2+ content and then decreases with the further increase in the Mn2+ content. Furthermore, they also exhibit excellent UV and air stability due to the existence of MCM-41 mesoporous silica and can be used as phosphors for solid-state lighting.
研究领域:
材料科学
·
光学
✓ 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）