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Background: Mesoporous materials like MCM-41 silica are highly regarded for their structural features and applications in adsorption and catalysis. This study enhances MCM-41's ability to adsorb cobalt and copper ions by introducing amine and Schiff-base groups, boosting its affinity for these pollutants and aiding in their removal from water solutions. Aims: To prepare MCM-41@NTPE and MCM-41@NTPE-BSAL and use them to adsorb heavy pollutants like cobalt and copper divalent ions from aqueous solutions. Methods: Mesoporous materials (MCM-41@NTPE and MCM-41@NTPE-BSAL) derived from rice husk were used as low-cost adsorbents for the adsorption of Co(II) and Cu(II) ions from aqueous solutions. Uptake experiments were performed to determine adsorption parameters like ion concentration, pH, exposure time, and adsorbent mass. Results: MCM-41@NTPE and MCM-41@NTPE-BSAL were characterized by FT-IR, FESEM-EDX, TEM, N2-adsorption-desorption, XRD, AFM and TGA/DTA. FT-IR confirmed the presence of silanol and siloxane groups. XRD and TEM indicated highly ordered hexagonal arrangements. N2-adsorption-desorption analysis revealed average pore diameters of 42.468 nm and 40.417 nm, total pore volumes of 0.094 cm3g-1 and 0.3384 cm3g-1, and specific surface areas of 8.873 m2g-1 and 37.802 m2g-1 for MCM-41@NTPE and MCM-41@NTPE-BSAL, respectively. TGA showed three mass reduction steps. Adsorption assessment showed pH 6 and 5 were optimal for Co(II) and Cu(II) uptake, respectively, and uptake increased with initial concentration and exposure time. Discussion: XRD confirmed the hexagonal mesoporous structure, while BET analysis displayed amorphous natures. TGA suggested MCM-41@NTPE and MCM-41@NTPE-BSAL have potential for stability, although decomposing between 15-900°C. Electron microscopy revealed ordered hexagonal arrangements. The materials demonstrated high efficacy in extracting copper and cobalt ions from aqueous solutions. Conclusions: Two mesoporous silica materials (MCM- 41@NTPE and MCM-41@NTPE-BSAL) were prepared from rice husk by functionalizing MCM-41. Adsorption assessment showed uptake depended on exposure time, pH, initial concentration, and adsorbent mass. MCM- 41@NTPE-BSAL exhibited better ion uptake than MCM-41@NTPE. [ABSTRACT FROM AUTHOR]

This study explores the influence of micelles on the evolution of MCM−41's pore structure via 24 h hydrothermal treatments in a range of temperatures from 100 °C to 200 °C. MCM−41 was characterized using BET, SAXD, FTIR, TEM, and TG-DSC. The findings demonstrate that with temperature elevation from 100 °C to 160 °C, the micelles undergo expansion, leading to an enhanced lattice constant from 4.50 nm to 4.96 nm and an increase in pore diameter from 3.17 nm to 3.45 nm, while maintaining the structural orderliness of the pore channels. Upon cooling, the reversible contraction of micelles and the strategic addition of water glass contribute to a reduction in pore size. However, at a threshold of 180 °C, the SAXD (100) peak's half-peak width surges by approximately 40% relative to that at 160 °C, illustrating a progressive disruption of the hexagonal configuration of MCM−41. Coupled with elevated silica dissolution at higher temperatures in an alkaline solution, a total disintegration of the ordered pore structure at 200 °C results in a drastic reduction in the specific surface area to 307 m2/g. These results are beneficial to developing structural transformation mechanisms of MCM−41 materials and designing mesoporous materials via temperature modulation innovatively. [ABSTRACT FROM AUTHOR]

The magnetic mesoporous silica material, Mag-MCM-41, was synthesized by coating magnetite (Fe3O4) nanoparticles with a mesoporous material called MCM-41. Mag-MCM-41 and modified nanomaterials Mag-MCM-41-NN and Mag-MCM-41-NNFe+3 which were modified with aminopropyl functional groups. In water and wastewater, phosphate anions are considered significant contaminants due to their detrimental impact on the environment. They promote the growth of algae, leading to eutrophication. The purpose of this study is to investigate the removal of phosphate anions from aqueous solutions using modified magnetic silica particles. The Mag-MCM-41 material exhibits hexagonal properties and belongs to the class of "mesoporous" materials. It has a surface area of 923 m².g-1, which was determined through N2 adsorption-desorption isotherms, FTIR, TEM, BET, and SAXS analysis. Kinetic and adsorption isotherm studies were conducted using Mag-MCM-41, Mag-MCM-41-NN, and Mag-MCM-41-NN-Fe+3 adsorbents to examine the behavior of phosphate anions. The kinetic and adsorption isotherm studies of phosphate anions revealed that the adsorption process on Mag-MCM-41, Mag-MCM-41-NN, and Mag-MCM-41-NN-Fe+3 adsorbents followed the chemical adsorption mechanism. Phosphate adsorption on all adsorbents occurred in a monolayer, and the MCM-41-NN-Fe+3 adsorbent exhibited the highest maximum adsorption capacity (qm) value of 112.87 mg.g-1 compared to the other adsorbents. [ABSTRACT FROM AUTHOR]

The synthesis and characterization of MCM‐41 magnetic mesoporous material, which has been modified with zirconium‐thiouracil complex (M‐MCM‐41@TU‐ZrO), has been conducted and thoroughly analyzed using an array of techniques such as X‐ray diffraction (XRD), energy‐dispersive X‐ray spectroscopy (EDX), elemental mapping, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT‐IR), Brunauer‐Emmett‐Teller (BET), inductively coupled plasma‐optical emission spectrometry (ICP‐OES), thermogravimetric analysis (TGA) and vibrating sample magnetometer (VSM). The catalytic performance of M‐MCM‐41@TU‐ZrO was tested in the synthesis of phenyl aryl sulfides through a three‐component coupling reaction of aryl halides/phenolic esters with phenylboronic acid and sulfur powder in the presence of a base in PEG200 at 80–90°C. Also, the synthesis of symmetrical diaryl sulfides using aryl halides and sulfur powder and M‐MCM‐41@TU‐ZrO as a nanocatalyst in dimethyl sulfoxide at 120°C was investigated. A major novelty is that this is the first time that a highly efficient magnetically recyclable zirconium nanocatalyst is used for the synthesis of unsymmetrical diaryl sulfides in the presence of arylboronic acid/S8 system as thiolating agent and phenolic esters as cross‐coupling partners. The other advantages of this method are as follows: (a) the structurally diverse phenyl aryl sulfides have been synthesized in good to high yields in PEG as a green solvent; (b) starting materials, sulfur source, and catalyst are commercially available, cheap, non‐toxic, and chemically stable; and (c) M‐MCM‐41@TU‐ZrO nanocatalyst was easily removed from the reaction mixture using an external magnet and reused numerous times without any significant change in activity. [ABSTRACT FROM AUTHOR]

Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This research presents the development of composite membranes incorporating MCM-41 mesoporous material which poses the potential to diminish membrane fouling by organic dyes molecules; a major problematic in leather tanning and textile industries. MCM-41 mesoporous was successfully synthesised and incorporated into polyethersulfone (PES) via the classical non induced phase separation (NIPS) at several loading ratios (0–1 wt.%). Characterisation process was carried out by a series of experimental tools to evaluate the composite membranes. All modified membranes displayed a notable enhancement in their hydrophilicity, roughness, porosity, mechanical strength. Besides that, composite membranes showcased an increase in their antifouling activity against the two dye models, Acid Black and Rose Bengal with increasing the MCM-41 ratio up to 0.5 wt.%. The fabricated PES-NF membranes manifested greater performance in terms of permeation characteristics compared to the pristine PES membrane, while maintained their selectivity against both dye solutions as high as 99%. [ABSTRACT FROM AUTHOR]

Selective oxidation of organics over an efficient heterogeneous catalyst under mild liquid phase conditions is a very demanding chemical reaction. Herein, we first report the modification of the surface of mesoporous silica MCM-41 material by phosphate for the efficient incorporation of Ti(IV) in the silica framework to obtain highly ordered 2D hexagonal mesoporous material STP-1. STP-1 has been synthesized by using tetraethyl orthosilicate, triethyl phosphate, and titanium isopropoxide as Si, P, and Ti precursors, respectively, in the presence of cationic surfactant cetyltrimethylammonium bromide (CTAB) under hydrothermal conditions. The observed specific surface area and pore volume of STP-1 were 878 m2g−1 and 0.75 ccg−1, respectively. Mesoporous STP-1 has been thoroughly characterized by XRD, FT-IR, Raman spectroscopy, SEM, and TEM analyses. Titanium incorporation (Ti/Si = 0.006) was confirmed from the EDX analysis. This mesoporous STP-1 was used as a heterogeneous catalyst for the selective oxidation of styrene into benzaldehye in the presence of dilute aqueous H2O2 as an oxidizing agent. Various reaction parameters such as the reaction time, the reaction temperature, and the styrene/H2O2 molar ratio were systematically studied in this article. Under optimized reaction conditions, the selectivity of benzaldehyde could reach up to 93.8% from styrene over STP-1. Further, the importance of both titanium and phosphate in the synthesis of STP-1 for selective styrene oxidation was examined by comparing the catalytic result with only a phosphate-modified mesoporous silica material, and it suggests that both titanium and phosphate synergistically play an important role in the high selectivity of benzaldehyde in the liquid phase oxidation of styrene. [ABSTRACT FROM AUTHOR]

A highly efficient heterogeneous copper(I)‐catalyzed three‐component coupling of terminal alkynes, diazoesters and aldehydes has been achieved by using 10 mol% of copper(I) iodide complex [N,N‐CuI‐MCM‐41] anchored on 2‐aminoethylamino‐modified mesoporous material MCM‐41 as the catalyst under mild conditions, delivering a wide variety of 2‐alkoxycarbonyl‐substituted (E)‐1,3‐enynes in mostly good to high yields with excellent stereoselectivity. The heterogenized copper(I) complex can be facilely prepared from inexpensive reagents by using a simple procedure and exhibits a remarkably higher catalytic activity than CuI, and can be recycled more than ten times without a significant drop in its catalytic efficiency. This protocol represents the first example of heterogeneous copper‐catalyzed stereoselective construction of functionalized 1,3‐enynes from simple and commercially available starting materials. [ABSTRACT FROM AUTHOR]

Catalytic distillation is a technology that combines a heterogeneous catalytic reaction and the separation of reactants and products via distillation in a single reactor/distillation system. This process combines catalysis, kinetics, and mass transfer to obtain more selective products. The heterogeneous catalyst provides the sites for catalytic reactions and the porous surface for liquid/vapor separation. The advantages of catalytic distillation are energy savings, low waste streams, catalyst longevity, higher conversion, and product selectivity; these properties are interesting for petrochemical and petroleum industries. For this study, 100 mL of atmospheric residue of petroleum (ATR) was distilled in the presence of 1.0 g of a micro/mesoporous catalyst composed of a HY-MCM-41, and the reactor used was an OptiDist automatic distillation device, operating according to ASTM D-86 methodology. The products were collected and analyzed by gas chromatography. The samples of ATR, HY/ATR, and HY-MCM-41/ATR were analyzed by thermogravimetry (TG) to determine the activation energies (Ea) relative to the thermal decomposition of the process, using the Ozawa–Flynn–Wall (OFW) kinetic model. The obtained results show a potential catalytic distillation system for use in the reaction of heavy petroleum fractions and product separation from the HY/MCM-41 micro/mesoporous catalyst. The TG data revealed two mass loss events for ATR in the ranges of 100–390 and 390–590 °C, corresponding to volatilization and thermal cracking, respectively. The Ea determined for the thermal degradation of the ATR without a catalyst was in the range of 83–194 kJ/mol, whereas in the presence of the HY-MCM-41 catalyst, it decreased to 61–105 kJ/mol, evidencing the catalytic effect of the micro-mesoporous material. The chromatography analysis allowed for the identification of gasoline and a major production of diesel and gasoil when the HY-MCM-41 mixture was used as the catalyst, evidencing the synergism of the combined effect of the acid sites, the crystalline phase, and the microporosity of the HY zeolite with the accessibility of the hexagonal mesoporous structure of the MCM-41 material. [ABSTRACT FROM AUTHOR]

In this work, the formation of levulinic acid (LA) as one of the top-twelve chemical building blocks from glucose was studied. In particular, the formulations of heterogeneous acid catalysts based on SBA-15, MCM-41 mesoporous silica was carried out and their performance in catalytic conversion of glucose to LA were assessed and compared with commercial H-Beta-25 (SiO2/Al2O3 = 25) microporous zeolite. The high surface area, suitable porosity, balanced acid sites were considered as the main factors of a proper catalytic performance. Thus, essential modification of mesoporous SBA-15 and MCM-41 materials was carried out by introducing Al in their structures for Lewis acid sites improvement. Alumina was introduced to SBA-15 by post synthesis evaporation impregnation method while it was embedded inside the MCM-41 mesoporous material during the synthesis. In addition, Brønsted acidity was introduced via post-synthesis grafting of sulfonic acid groups. The textural and morphological features and acidity of the materials were investigated using N2 physisorption, SEM, EDX, TEM, XRD and pyridine-FTIR. All catalysts were tested for aqueous glucose conversion in an autoclave at 180 °C. Al-MCM-SO3H has shown the best performance with 54% of LA yield after 4 h reaction. According to Py-FTIR introduction of alumina and sulfonic acid groups improved weak and medium Lewis and Brønsted acid sites. However, the Brønsted to Lewis acid site ratio (B/L) was higher for Al-MCM-SO3H compared to SBA-Al-SO3H leading the reaction pathway to LA. H-Beta-25 zeolite displayed a poor performance because of harsh medium and strong acid sites catalyzing humins formation. [ABSTRACT FROM AUTHOR]

The main objective of this work was to synthesize hexagonal mesoporous materials such as MCM-41 from optimized protocols and to test their effectiveness in adsorption of different pharmaceutical pollutants. First, pore size and the specific surface area of the base materials have been modified by incorporation of amino groups in post-synthesis, by selective extraction of the loaded groups and finally by calcination. Subsequently, adsorbent products were characterized by their mesoscopic textures, structures and controls using different methods: X-Ray Diffraction (XRD), Specific Surface Area (BET), Fourier Transform Infrared Spectroscopy (FTIR), Thermogravimetric analyses (TGA/DTA) and Zetametry. Finally, their adsorption capacities were evaluated using several pharmaceutical residues under standard conditions (such as Diclofenac, Cefalexin ...). The results obtained during the adsorption study showed the effectiveness of these materials for the decontamination of aqueous media contaminated with pharmaceutical residues. Kinetic and adsorption isotherm studies were carried out to clarify the method of binding of the selected pharmaceutical pollutants to the tested materials. [ABSTRACT FROM AUTHOR]

The present study aimed to evaluate the potential of mesoporous silica MCM-41 and Al-MCM-41 (molar ratio Si/Al = 20) for the removal of Rhodamine 6G (Rh6G) from aqueous solution. The adsorbents were characterised by XRD, FTIR, SEM-EDX, BET, and UV-Raman. Obtained results related to XRD analysis indicated that the MCM-41 structure remained intact after the incorporation of Al species. Kinetic adsorption study showed that the higher removal (88.75 %, 26.62 mg g−1) of Rh6G dye was achieved by Al-MCM-41 at 60 min. FTIR analysis showed that hydrogen bonding played the dominant role in the Rh6G removal mechanism, while the pH results showed that electrostatic interaction was also a key factor. This study shows that the prepared mesoporous materials are inexpensive and efficient adsorbents for the removal of cationic dyes. [ABSTRACT FROM AUTHOR]

Cu(II)-acetohydrazide functionalized CMK-3 and MCM-41 mesoporous materials prepared by a simple, efficient and less expensive protocol. These catalysts are carefully characterized by SEM, XRD, TGA, FT-IR, EDX, ICP‐OES and BET techniques. The obtained nanostructured compounds were also used as a green, efficient, heterogeneous and reusable catalytic systems for the synthesis of 2-amino-4-H-pyran and 2,4,5-trisubstituted imidazole derivatives. Also the results and behavior of the two catalysts were comparable in some cases. The synthesized nanocatalysts could be easily recovered from the reaction mixture and reused many times without significant loss of their catalytic activities. [ABSTRACT FROM AUTHOR]

This work presents for the first time the systematic preparation of a novel carbon nanotube-MCM-41 hybrid employing the mesoporous material MCM-41 as a successful dispersant for multiwall carbon nanotubes (MWCNTs). Relevant dispersion variables such as the amount of MWCNTs, MCM-41 concentration, and sonication time were optimized through a central composite design (CDD)/response surface methodology (RSM). Several solvents were evaluated and N,N-dimethylformamide (DMF) was selected because it allowed reaching stable dispersions with very good electrochemical response. The electrochemical performance of glassy carbon electrodes (GCE) modified with different hybrids was evaluated by cyclic voltammetry (CV) using ascorbic acid (AA) as redox marker, while their surface morphology was characterized by SEM microscopy. The optimal MWCNT–MCM-41 dispersion condition was 0.75 mg mL−1 MWCNTs, 0.25 mg mL−1 MCM-41, and 30 min sonication. Both, electrochemical results and SEM images correlate with a percolation behavior from MWCNT–MCM-41 hybrid. Electrooxidation of AA at GCE modified with the optimal hybrid occurred under diffusion control and exhibited an enhanced current response (65 μA) and a lower overvoltage (−0.005 V) compared to bare GCE (ip = 22 μA, Ep = 0.255 V). The amperometric response of AA at GCE/MWCNT–MCM-41 exhibited remarkable figures of merit, including an ultralow detection limit (1.5 nM), high sensitivity (45.4 × 103 μA M−1), excellent short- and long-term stability, and very good anti-interference ability for AA detection. The analytical applicability of the developed electrochemical sensor was evaluated by sensing AA in several real samples, showing excellent correlation with the values reported by manufacturers in both pharmaceutical and food samples. [ABSTRACT FROM AUTHOR]

Mesoporous MCM-41 material was synthesized and it was successfully incorporated with Vanadium at room temperature by simple co-precipitation method. Higher portion of V+5 was noticed in the framework of V-MCM-41 material without disturbing the mesoporosity. The materials were characterized by X-ray diffraction (XRD), Nitrogen adsorption-desorption studies (BET method, SBET), scanning electron microscope coupled with electron dispersive x-ray spectroscopy (SEM-EDAX), and UV-Vis diffused reflectance (UV-Vis DRS) techniques. The catalytic activity of the synthesized materials were investigated toward the removal of orange G dye (OG) and was observed that the VMCM-41 has superior catalytic activity in the presence of hydrogen peroxide. [ABSTRACT FROM AUTHOR]

Understanding the effects of cerium in the formaldehyde (HCHO) catalytic oxidation performance over Ag/MCM-41 catalysts, cerium modified MCM-41 mesoporous materials (Ce-MCM-41) with different ratios were synthesized by one-step hydrothermal method. The activity test results showed that Ag/Ce-MCM-41 with the ratio of Si:Ce = 1:1 catalysts could reach complete HCHO oxidation above 130 °C. These Ag/Ce-MCM-41 catalysts with different Si:Ce ratios were characterized by IR, SXRD, XRD, TEM, UV–Vis, Raman, XPS and H2-TPR. The results show that the interactions between Ag and Ce, between Ce and SiO2 in our Ag/Ce-MCM-41 are enhanced due to adding Ce to MCM-41. The presence of Ce-SiO2 interaction dramatically enhances the reducibility of surface-capping oxygen of CeO2, promotes the bulk oxygen migration to the surface and creates oxygen vacancies in the bulk region of CeO2 and the presence of more oxygen vacancies can facilitate the anchoring and dispersing of Ag particles, which lastly improves the interaction between Ag and Ce. In addition, the amount of formed oxygen vacancy is the highest when the Si:Ce = 1:1. The activation of surface oxygen is closely related to oxygen vacancy, O2 may be transformed into the highly active O2−. The high active O2− in surface adsorbed oxygen promotes the activation of oxygen molecules and enhanced the catalytic oxidation of HCHO. [ABSTRACT FROM AUTHOR]

Copyright of Brazilian Journal of Biology is the property of Instituto Internacional de Ecologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The mesoporous material silica MCM-41 was synthesized under basic media using pure silica, cetyltrimethylammonium bromide and tetramethylammonium hydroxide at 90°C, and then hydrothermally treated by dihexylamine (DHA) at 130°C for 72 h in order to inflate the pores. The post-synthesized material (DHA-41A), the material obtained after selective ethanol extraction of DHA (DHA-41B) and the organic-free material obtained after carbonization of DHA-41A and/or DHA-41B afford (DHA-41C). Small angle X-ray diffraction, nitrogen adsorption–desorption measurements, FT-IR, thermogravimetry and zetametrie were used to characterize all the samples. The samples were evaluated as adsorbent for two dyes Naphtol Green B (NGB) as anionic dye and Rhodamine B (RB) as cationic dye. DHA-41A and DHA-41C were found to be fast adsorbent for the anionic and the cationic dye respectively. Adsorption capacities of NGB onto DHA-41A and RB onto DHA-41C, were found 444.55 and 372.59 mg/g respectively. Adsorption kinetic data were tested using pseudo-first-order and pseudo-second-order models and intraparticle diffusion. Adsorption data were modeled using Langmuir, Freundlich and Sips adsorption isotherms. The result revealed that the adsorption of the anionic dye onto DHA-41A and the cationic dye onto DHA-41C, fitted very well with the Langmuir and Sips isotherm model naht Freundlich isotherm model. [ABSTRACT FROM AUTHOR]

Nanostructured mesoporous materials of MCM-41 type were synthesized using a natural, non-toxic, and cheap source of silica from rice husk. Then, this pure silica was modified with several Fe loadings by a wet impregnation method. The chemical and physic properties of MCM-41 solids obtained were similar to those of MCM-41 synthesized from commercial silica by conventional method. Thus, all catalysts exhibited good structural regularity preserving the mesoporosity after the metal incorporation. The performance of the Fe/MCM-RHA composites as photo-Fenton heterogeneous catalysts was evaluated for photocatalytic degradation of different endocrine-disrupting chemicals (EDCs), such as herbicides (atrazine), and compounds derived from the plastic industry (bisphenol A) and the pharmaceutical industry (acetaminophen). The major photo-catalytic efficiency obtained (Fe/MCM-RHA(2.5)) is consistent with the highest presence of iron species, which are finely dispersed and stabilized on the silica structure, the isolated Fe3+ ions being the accessible and active sites for the reaction. Finally, a cheaper solid arising from the valorization of residual biomass and with excellent photocatalytic performance for the degradation of EDCs (above 99%, 75%, and 60% for BPA, ATZ, and ACE respectively, in a reaction time of 240 min) was obtained. [ABSTRACT FROM AUTHOR]

Reactive adsorption desulfurization of a model fuel containing dibenzothiophene with various adsorbents was studied. Adsorbents based on MCM-41 mesoporous material with supported Ni and ZnO phases were prepared and characterized. The desulfurization activity of the material in a fixed-bed flow-through reactor was compared to that of alumina-based adsorbents. The adsorbent based on MCM-41 considerably surpasses its analog on Al2O3 support in the adsorption capacity in reactive adsorption desulfurization of dibenzothiophene at 350°С, pressure of 2 MPa, and feed space velocity of 1 h–1. [ABSTRACT FROM AUTHOR]

The current study investigated the performance of the adsorption process for the remediation of secondary treated wastewater from the Al-Daura Oil Refinery in Central Iraq, employing batch and continuous (fixed-bed column) adsorption systems. A functionalized mesoporous material with amine groups (NH2-MCM-41) was used as an efficient adsorbent for the removal of various types of polycyclic aromatic hydrocarbons (PAHs) compounds. The highest removal efficiency of PAHs in batch and continuous adsorption systems were 85.7% and 74.24%, respectively. The batch adsorption system was operated based on our earlier work, using the NH2-MCM-41 dosage = 0.4 g/L, time = 50 min, rpm = 200, and pH = 7. For this case, the removal efficiency of the chemical oxygen demand was 45%. The fixed-bed column (i.e., bed height = 8 cm, flow rate = 1 mL/ min, and pH = 7) showed a removal efficiency of 40%--66% for the chemical oxygen demand as well as 74.24% PAHs degradation. The results indicated that functionalized MCM-41 can be used as an effective adsorbent for the removal of different types of polycyclic aromatic hydrocarbons compounds using either batch or continuous (fixed-bed column) adsorption systems in oil refineries. [ABSTRACT FROM AUTHOR]

MCM-41-SO3H, ordered mesoporous silica material MCM-41 with covalently anchored sulfonic acid groups, was used as a solid acid catalyst for the convenient, efficient, and 'green' synthesis of 2-amino-6-(hydroxymethyl)-8-oxo-4-aryl-4,8-dihydropyrano[3,2-b]pyrans via a one-pot, three-component reaction of 5-hydroxy-2-(hydroxymethyl)-4H-pyran-4-one, aldehydes and malononitrile in aqueous media. [ABSTRACT FROM AUTHOR]

Antioxidant active packaging films were prepared with low‐density polyethylene (LDPE) being incorporated with α‐tocopherol‐loaded MCM‐41 mesoporous silica. In order to study the influence of pore size and morphology of the mesoporous material on physical and release properties of films, the mesoporous materials were synthesized with various pore sizes and morphologies. MCM‐41 mesoporous silica materials before and after being loaded with α‐tocopherol were characterized, as well as the active films. The results show that physical properties and release profiles of active films can be changed when being incorporated with mesoporous materials with different structures: crystallinity of films prepared ranged from 11.30% to 18.13%, and the tendency of change was in good accordance with that of specific surface area of mesoporous silica materials. Variation of release rates of the antioxidant in packaging films can be achieved by changing MCM‐41 pore size, and the release period can be prolonged by ~64% in the scope of this study. These demonstrate that LDPE/α‐tocopherol/MCM‐41 films with adjustable release profile and physical properties have the potential to be used as antioxidant active packaging films. [ABSTRACT FROM AUTHOR]

Adsorption isotherms with a) MCM-41 and b) Ni/MCM-41 varying the Si/Al ratio with Q in the presence of DBT, with a ratio S:N = 1. Dashed lines represent the Langmuir or Freundlich model. • Q was adsorbed with MCM-41 and Si/Al ratio as 150 and ∞. • With Ni/MCM-41 the sulfur adsorption with Si/Al = 5 is presumably related to the Lewis sites acidity. • Langmuir and Freundlich's isotherm were adjusted for N adsorption and MCM-41 presenting higher values of adsorption. • Freundlich isotherm was adjusted for sulfur adsorption and it was the best model for both adsorbents. In this study, two mesoporous materials such as MCM-41 and Ni/MCM-41 were modified with Al at different Si/Al ratios. The mesoporous materials were proved as sorbents of heterocyclic nitrogen and sulfur compounds employing quinoline (Q) and dibenzothiophene (DBT), respectively, as model molecules of that precursor pollutants at the same concentrations of ppmw of nitrogen and sulfur (N:S = 1 ratio). The sample with the highest Si/Al ratio showed the highest specific surface, and at low Si/Al decreased the specific surface. With X-ray diffraction (XRD) the Ni containing in MCM-41, there is a clear trend and the highly hexagonal ordered sample is the one without Al and once the Al is added, the hexagonal ordering is highly modified. Employing NH 3 -TPD and NMR revealed that the samples with Si/Al = 5 and 16 have higher Lewis acid sites than another ratio of Si/Al. The modification successfully added small amounts of Ni that did not collapse the pore structure but increased the density of surface (acidic) groups that in turn favored the uptake of the sulfur compound through π-complexation adsorption mechanism. It is also possible to recognize that the samples with a Si/Al ratio of 5 and 16 revealed the presence of the highest surface density of weak acid sites for both sorbents. Adsorption experiments were carried out in a batch adsorption system at 313 K and atmospheric pressure using a model mixture from diesel containing: DBT, Q, and 40 ml of dodecane. The sulfur adsorption was substantially improved when Ni was incorporated to MCM-41; for example, at 250 ppmw of N uptake of DBT was almost twice than MCM-41 alone. This result would indicate that Ni/MCM-41 could remove both molecules but mainly the nitrogen molecule at high concentrations. The Langmuir and Freundlich adsorption isotherms were used for all materials considering Q in the presence of DBT depending on the Si/Al ratio. This behavior did not happen for the DBT whose behavior was modelled by an isotherm of the Freundlich type for Ni/MCM-41 and adsorbed in acid sites and multilayer. Lastly, experimental results indicated that MCM-41 with Si/Al = ∞ has the highest (Q/DBT) selectivity of 13,390 at 50 ppmw N compared to another Si/Al ratio, for example, at 250 ppmw N. [ABSTRACT FROM AUTHOR]

• A novel magnetic catalysts was synthesized and characterized. • Different amount of connecting parts exposes the various number of –OCH 3 in catalysts. • Various numbers of exposed groups shows different oxidative desulfurization efficiency. • The catalyst can be easily recovered and reused by external magnet. Magnetic-heteropolyacid mesoporous catalysts have been obtained, in which magnetic Fe 3 O 4 in the center of MCM-41 mesoporous materials and APES (3-aminopropyl-triethoxysilane) used to link heteropolyacid. To noted, for the various molar ratio APES used in the synthesized process, different numbers of –OCH 3 were exposed in the final products (zero, one and two), named Fe@MP-1, Fe@MP-2 and Fe@MP-3, respectively. Interestingly, the three kinds of catalysts exhibited the various DBT removal efficiency during the oxidative desulfurization process, mainly due to their structure variance leading to be the research focus in this work. Among them, under the oxygen in air as oxidant, Fe@MP-1, with no –OCH 3 exposed outside, showed the excellent desulfurization activity with 100% DBT conversion in 90 min and behaved nearly no obvious decrease after at least 8 recycling times. Thus, the certain amount of APES, used to link active components with supporters, is suggested as an effective aspect to increase the oxidative desulfurization efficiency and maybe the different types of linkage also show the various influence, which will be focused on in our further researches. [ABSTRACT FROM AUTHOR]

A silica‐based MCM‐41 mesoporous material functionalized with cyanopropyl groups has been synthesized by cocondensation, characterized and applied to preconcentrate six parabens and three UV filters in river and swimming‐pool waters. The analytes were quantified by ultra‐high performance liquid chromatography‐tandem mass spectrometry, according to the Directive 96/23/EC. Even though matrix effect was negligible, quantification in river water samples with the standard addition approach improved the recoveries obtained using solvent‐based and even with matrix‐matched calibration. The method quantification limits in river water samples were 0.05 ng/mL for 2,4‐dihydroxybenzophenone and 0.01 ng/mL for the rest. Recoveries, evaluated for a concentration level of 0.5 ng/L, were in the range 93.5‐107.6% for parabens and in the range 64.2‐85.8% for UV filters, with relative standard deviations intraday ≤10.2 and 10.8%, respectively. This parameter, evaluated for a concentration level of 0.1 ng/L, ranged between 98.3 and 110.4% for parabens and between 61.9 and 89.9% for UV filters, with relative standard deviation intraday ≤15.3 and 15.5%, respectively. The two UV filters with lower recoveries were the most affected by the addition of sodium chloride. River and swimming pool waters were analyzed and all the personal care products were found in the swimming pool water, whereas only methylparaben was detected in the river water. [ABSTRACT FROM AUTHOR]

The development of methods for lead ion determination in various biological and environmental samples is both necessary and challenging. In this context, considering the properties of both SBA-15 and MCM-41 mesoporous materials and the role of NH2-functional groups grafted on the silica surface (SBA-15-NH2 and MCM-41-NH2), the aim of the study was to investigate the electrochemical detection of Pb2+ by means of silica-modified glassy carbon electrodes (GCEs). The square wave anodic stripping voltammetry (SWASV) was used to characterize the modified electrodes with four different samples of ordered mesoporous silica (OMS) powders, mentioned above. Additionally, scanning electron microscopy (SEM) was used to characterize these modifiers. Pb2+ exhibits a well-defined oxidation peak (around − 0.5 V vs. Ag/AgCl/KClsat) and high peak current at either bare or OMS-modified glassy carbon electrodes, but the best response was recorded in the case of GC/SBA-15-NH2-modified electrode in 0.1 M acetate buffer. The performance of the prepared electrodes is highlighted by good analytical parameters (satisfies the requirements of low cost and rapid results), which recommends them to be used for real sample analysis. [ABSTRACT FROM AUTHOR]

Microwave synthesis method is a green chemical process with mild reaction conditions, fast reaction, and low energy consumption. In this work, an order mesoporous silica material MCM-41 was synthesized by microwave technology. Functionalized MCM-41 was prepared by wet impregnation with polyethyleneimine (PEI). XRD, SEM, TEM, DLS, N2 adsorption-desorption, FTIR, and TG were used to characterize the physicochemical properties of samples. Furthermore, CO2 absorption performance in water in the presence of uncalcined MCM-41 and PEI-MCM-41 nanoparticles was evaluated. In addition, the mechanisms of enhanced absorption were also elaborated. The experimental results indicated that the optimum conditions for preparation of MCM-41 were the microwave time of 15 min, microwave temperature of 100°C, and microwave power of 200 W. Under this condition, MCM-41 with narrow particle size distribution, average diameter of 50 nm, and S BET of 1210.3 m2g-1 was obtained. The enhancement effect of PEI-MCM-41 nanoparticles was more obvious than that of uncalcined MCM-41. PEI-MCM-41 as a promoter not only increased the CO2 diffusion rate but also enhanced the adsorption capacity due to the fact that it owns more active sites that may react with CO2. The CO2 absorption improvement of PEI-MCM-41 (0.1 wt%)/H2O was 25.35% higher than that of water. [ABSTRACT FROM AUTHOR]

n-Hexadecane hydroconversion has been investigated in a series of bifunctionnal metal/acid catalysts featuring distinct well-defined pore architectures. The acidic components were prepared from dealuminated Y zeolites with Si/Al of 15 and 30 post treated in alkaline medium to generate ordered or non-ordered secondary networks of mesopores and from aluminated ordered mesoporous materials MCM-41, MCM-48, KIT-6 type materials and amorphous silica gel. Activity relates linearly to the strength and number of strong Brönsted acid sites, while selectivity, more precisely the yield in isomerization products, scales directly with the mesopore volume of the catalyst. The architecture of the mesoporous network, namely the ordering, interconnectivity, homogeneity of the mesopores, affects little catalytst behavior. Confrontation of catalytic data with diffusion measurements suggests the existence of an optimal mesopore size above which the number of strong Brönsted sites and the mesopore volume are the only parameters governing catalytic performance. [ABSTRACT FROM AUTHOR]

ZSM-22 zeolite was desilicated and recrystallized to obtain a hierarchically porous material with wellestablished MCM-41 mesoporous structure on the outer surface. By choosing three different linear n-alkanes (n-heptane, n-dodecane, and n-hexadecane) as reactants, the impact of the MCM-41 mesoporous shell on isomerization performance was studied systematically. Compared with conventional and desilicated catalysts, the Pt-loaded recrystallized ZSM-22 catalyst exhibited lower cracking activity and rather higher isomerization selectivity. Detailed product analysis and kinetic study revealed that the isomerization activity was mainly determined by the interaction of hydrocarbon molecules in the confined reaction space with the channels of ZSM-22 zeolite. The Brønsted acid sites in the MCM-41 mesoporous shell in the recrystallized material also worked as active sites for the isomerization at high conversion leading to the significantly enhanced selectivity of multi-branched isomers due to the open mesoporous structure providing space for the formation of multi-branched isomers. Furthermore, with the diffusion restriction of the extra mesoporous shell, the residence time of reactants was prolonged, which promoted secondary isomerization at microporous pore openings. The Pt-loaded ZSM-22/MCM-41 hierarchically porous material was very attractive due to the high yield of multi-branched isomers, and the preferable hexadecane isomerization performance revealed its potential application in Fischer-Tropsch synthesis dewaxing processes. [ABSTRACT FROM AUTHOR]

Heterogeneous ordered mesoporous silica materials catalyst, MCM-41@Schiff base-Co(AcO)2, reveals high catalytic performance within the synthesis of pyran derivatives using the multicomponent reaction of aldehydes, malononitrile and 2-naphthol (or cyclohexane-1,3-dione) in water. The reactions afforded the desired products in high yields (up to 97% and 95%). The substantial feature is that the mesoporous-complex catalyst could be easily separated from the reaction mixture by centrifugation and reused at least 6 times with more than 80% yield in activity. The gram-scale experiments were achieved with good yields and implied that the catalytic method was effective and convenient for heterocyclic synthesis. What is more, the synthesized catalyst was characterized using various spectroscopic techniques to obtain the structural and functional features. The analysis results confirmed that the Co-Schiff base complex immobilized on the surface of mesoporous materials MCM-41. Finally, a plausible reaction mechanism was proposed. [ABSTRACT FROM AUTHOR]

• Synthesis and characterizations of amine impregnated mesoporous materials. • Effects of amine loadings, temperature and CO 2 partial pressure on adsorption. • Highest CO 2 adsorption of 2.34 mmol CO 2 /g at 1 bar CO 2 partial pressure. • Toth and Sips isotherm models are best suited to correlate CO 2 adsorption data. • Isosteric heat of adsorption calculation using Van't Hoff plot. In this study, a composite mesoporous silica material MCM-41 (Mobil composite matter) is impregnated with monoethanolamine (MEA) as primary linear amine, benzylamine (BZA) as primary cyclic amine and N-(2-aminoethyl) ethanolamine (AEEA) as secondary diamine and the effects of amine loading, amine type, CO 2 partial pressure and adsorption temperatures on the CO 2 adsorption are investigated. The CO 2 adsorption performances of MCM-41 and amine impregnated MCM-41 samples are studied up to 1 bar of CO 2 partial pressure and the temperature range of 25–60 °C. The amine loadings (% impregnation) are optimized for maximum CO 2 uptake. The materials are characterised using N 2 adsorption/desorption isotherm, Fourier Transform Infrared (FT-IR) Spectroscopy, Thermogravimetric (TGA) and Elemental (CHNS) analysis. The materials have shown good structural and thermal stability. The MCM-41-40%AEEA, MCM-41-40%BZA and MCM-41-50%MEA samples are exhibited the CO 2 adsorption capacity of 2.34 mmol/g (102.98 mg/g), 0.908 mmol/g (39.96 mg/g) and 1.47 mmol/g (64.69 mg/g) respectively. The CO 2 uptake of MCM-41-40%AEEA is 3.5 times higher than that of in MCM-41 (0.68 mmol/g) and it is also the highest reported value as di-amine impregnated MCM-41. The results indicated that the adsorption capacities of the materials (MCM-41 and MCM-41-40%AEEA) are decreased with an increase of adsorption temperature in the range of 25–60 °C. The Freundlich, Langmuir, Sips and Toth isotherm models are used to correlate and predict experimental CO 2 adsorption data. The Sips and Toth isotherm models are found to be better fitted with the experimental data. The isosteric heat of adsorption of MCM-41 and MCM-41-40%AEEA samples are also calculated from Van't Hoff plot using iSorbHP-win instrumental analysis software in the experimental temperature range. [ABSTRACT FROM AUTHOR]

The hybrid systems have been proven to be the most efficient technology for quickly lowering the concentration of dissolved pollutants in an effluent. In this work, the hybrid process was applied for adsorption of Methyl Orange (MO) dye pollutant from simulated wastewater by using mesoporous MCM-41 as an efficient adsorbents coupling with a microfiltration membrane (MF) in a membrane adsorption reactor (MAR) system. Batch adsorption process has been achieved to investigate the effect of various parameters, such as; adsorbent dose, initial adsorbate concentration and contact time. The equilibrium adsorption data of MO onto MCM-41 were analyzed by Langmuir and Freundlich adsorption isotherms. Adsorption of MO by mesoporous material MCM-41 arrived at equilibrium in 20 min, and the system obeyed Langmuir isotherm model (qmax = 151.51 mg/g), which is appropriate to monolayer adsorption. The kinetic pseudo-second order model appeared to match empirical datum completely. As for the hybrid process system (Mesoporous-MCM-41-MAR), the adsorption efficacy of MO and flux was 99% and 0.0006 ml/mm2 min respectively, which was generally due to contribution of both systems at the same time, adsorption by mesoporous MCM-41 and filtration by membrane system. The hybrid process not only removed MO with high efficacy, but also actively separated and recycled mesoporous MCM-41. [ABSTRACT FROM AUTHOR]

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Abstract ZrO 2 -promoted Cu ZnO catalysts were prepared through the sol-gel, conventional impregnation and modified impregnation methods using MCM-41 as support material and applied to the methanol steam reforming (MSR) reaction. The synthesized catalysts were characterized by the XRD, BET, FESEM, TEM, XRF, FTIR, H 2 -TPR and TGA methods. The determined physiochemical properties suggested that pretreatment of MCM-41 with acetic acid before metal impregnation remarkably decreases the size of the metal particles and improves their dispersion and reduction behavior. Among the synthesized catalysts, the Cu ZnO ZrO 2 /MCM-41 sample prepared through the modified impregnation method exhibited the best catalytic performance with 97.8% methanol conversion, 99.0% H 2 selectivity, 0.4% CO selectivity and the lowest level of coke deposition, at 300 °C. In addition, all catalysts resisted against deactivation by conserving their catalytic activity over 40 h operation, indicating that the use of high surface area MCM-41 as support, the ZrO 2 promoter, and the proper synthesis methods significantly enhanced the catalytic activity in the MSR process. Graphical abstract Image 1 Highlights • MCM-41 was used as a catalyst support in methanol steam reforming reaction. • Copper, zinc and zirconium were doped on MCM-41 by different methods. • Zirconium addition had a good effect on catalytic activity. • Treatment of MCM-41 before impregnation significantly reduced metal particles size. • Cu ZnO ZrO 2 /MCM-41 catalyst showed high catalytic activity in methanol steam reforming. [ABSTRACT FROM AUTHOR]

This paper shows a comparison of porous properties of aminopropyl-MCM-41 materials functionalised via the direct and indirect methods. The obtained materials were characterised using X-ray powder diffraction (XRD), transmission electron microscopy (TEM), thermogravimetric analysis-differential scanning calorimeter (TGA-DSC), adsorption/desorption isotherms of nitrogen, and Fourier-transfer infrared (FT-IR) spectroscopy. The results showed that the direct method provided the aminopropyl-MCM-41 material with well-ordered pores and high surface areas but with a lower quantity of grafted 3-aminopropyltriethoxysilane than the indirect method. To remove the organic template in the indirect method, solvent extraction with HCl/C2H5OH and calcination at 500°C were used, and the former gave a higher quantity of grafted 3-aminopropyltriethoxysilane in the resulting aminopropyl-MCM-41 materials. The experimental data were applied to the isotherm models of adsorption including Langmuir, Freundlich, Redlich–Peterson, and Sips either in the linear or nonlinear form. In order to avoid the bias of the determination coefficient and the error function method, the paired-samples t-test as an alternative method was first proposed to look for the most appropriate adsorption isotherms. The maximum adsorption capacity of Cd(II) and Pb(II) was 14.08 mg·g−1 and 64.21 mg·g−1, respectively. The mechanism of complexation and isoelectric interaction was suggested to explain the adsorption of Pb(II) and Cd(II) from aqueous solutions on aminopropyl functionalised MCM-41 in the range of pH from 2 to 9. [ABSTRACT FROM AUTHOR]

An efficient, highly stable, and ligand‐free catalyst consisting of Pd and monolacunary silicotungstate anchored to MCM‐41 was synthesized and characterized by various techniques. The synthesized catalyst was used for the hydrogenation reaction of cyclohexene as model substrate, and various reaction parameters were studied in order to optimize them for maximum conversion, 95 %, under mild conditions. The catalyst was regenerated by simply washing with methanol and reused up to three cycles without significant loss in activity. The viability of the catalyst was evaluated for different alkenes and ketones, and in all cases the conversion was found to be in the range of 92–99 %. It was also found that the sustainability arises from SiW11, which binds the palladium very strongly and thus does not allow its leaching into the reaction mixture. The new water‐tolerant catalyst comprising Pd‐SiW11 anchored to MCM‐41 was synthesized and characterized by various techniques and efficiently used for heterogeneous hydrogenation of various substrates. [ABSTRACT FROM AUTHOR]

The present investigation was carried out at Horticultural college and Research Institute for Women, Tamil Nadu Agricultural University, Trichy during Kharif 2017 with 30 mithipagal (Momordica charantia var. muricata.L) collected from different parts of Tamil Nadu to identify high yield and quality genotypes under sodic soil condition. Observation were recorded for the following traits viz, vine length, days to first male flower appearance, days to first female flower appearance, nodes of first male flower appearance, nodes of first female flower appearance, sex ratio, number of fruits per vine, fruit weight, fruit length, fruit girth, number of seeds per fruit, 100 seed weight, yield per vine, ascorbic acid, carotenoid content and total soluble solids. Among the genotypes MCM-19 was found to be the most promising genotype which recorded higher fruit yield per vine (0.72 kg) as well as other economic fruit yield components viz., fruit length (5.51 cm), fruit girth (6.47 cm), fruit weight (9.08 g), number of seeds per fruit (9.80), 100 seed weight (10.59 g) followed by MCM 22 and MCM 21. The highest total soluble solids was recorded in the genotypes MCM-4 (5.90 0brix) followed by MCM-21 (5.87 0brix), where as highest ascorbic acid was recorded in the genotypes MCM-26 (123.62 mg/100g) followed by MCM-22 (122.59 mg/100g). Hence selecting bitter gourd var. mithipagal genotypes with high fruit weight, more number of fruits per vine and seeds per fruit will help to improve yield per vine and quality of bitter gourd var fruits. [ABSTRACT FROM AUTHOR]

In the present study, the synthesis of [ZnO-Al] LDO/AgMCM-41 nanocomposite was suggested. The new nanocomposite was prepared in three steps: (i) synthesis of AgMCM-41 by incorporation of silver nanoparticles (Ag NPs) in MCM-41 via heat treatment method, (ii) preparation of layered double hydroxides (LDH) containing Zn and Al in AgMCM-41 through the co-precipitation method (iii) preparation of ZnO-Al layered double oxide (LDO) in AgMCM-41 by calcination of [Zn-Al] LDH/AgMCM-41. The new nanocomposite was a visible-light-driven photocatalyst for degradation of methyl-orange (MO) dye. The nanocomposite was characterized by XRD, TEM, BET, and DRS methods. The results showed the presence of Ag and ZnO NPs in nanocomposte. The nanocomposite indicated a surface plasmon resonance (SPR) band in the visible region related to silver NPs. The formation of [ZnO nanorods-Al] LDO over AgMCM-41 was observed by TEM. The photocatalyst demonstrated 90% removal efficiency for MO dye under visible light after 60 min. Kinetic research showed that the reaction rate constants [ZnO-Al]LDO/AgMCM-41 and [Zn-Al] LDH/AgMCM-41 were approximately 1.8 and 1.6 times higher than the apparent reaction rate constant of [Zn-Al] LDH. The photocatalytic activity of LDO was enhanced in presence of AgMCM-41 due to reduction of recombination rate of the electro-hole in ZnO semiconductor. [ABSTRACT FROM AUTHOR]

MCM-41 materials modified with Mg, Co, and Zn were prepared by direct synthesis method. The template-containing catalysts as bifunctional catalysts were evaluated for simultaneous esterification and transesterification reactions of waste cooking oil. All catalysts showed high FAME yield (≥92%) with methanol to oil mass ratio of 8:1, after 3 h. It was also found that [CTA]MCM-41 had a high catalytic activity achieving a maximum FAME yield of 93%. It might be because of the basicity and hydrophobicity induced by organic template. Furthermore, these catalysts can be reused without loss of catalytic activity due to the stability of organic template (CTA + ) inside the pores. [ABSTRACT FROM AUTHOR]

The paper presents the oxidation of natural limonene (extracted from waste orange peels) by 60 wt% hydrogen peroxide, in the presence of Ti-MCM-41 catalyst and in methanol as the solvent. The aim of the research was to develop the most favorable technological parameters for the process of limonene oxidation (temperature, molar ratio of limonene to hydrogen peroxide, methanol concentration, Ti-MCM-41 catalyst content and reaction time) by analyzing changes in the main functions describing this process: the conversion of limonene, selectivities of appropriate products, the conversion of hydrogen peroxide and the effective conversion of hydrogen peroxide. The process is environmentally friendly process and it uses renewable raw material - limonene and a safe oxidant - hydrogen peroxide. During the study, very valuable oxygenated derivatives of limonene were obtained: 1,2-epoxylimonene, its diol, carvone, carveol, and perillyl alcohol. These compounds are used in medicine, cosmetics, perfumery, food and polymers industries. [ABSTRACT FROM AUTHOR]

B-MCM-41 type nano-structured materials were prepared by direct hydrothermal synthesis. The time of hydrothermal treatment, the Si/B initial molar ratio and the nature of the hydroxide source in the synthesis process were analyzed. All the materials were characterized by XRD, N 2 adsorption, TEM, SEM, ICP-OES, FT-IR and adsorption of pyridine coupled to FT-IR spectroscopy. The role of hydroxide source is essential to achieve the incorporation of boron in the mesoporous structure. The relationship between the Boron content in the synthesis gel, the degree of introduction of tetra-coordinated B into the framework, the formation of nest silanols and the relative density of the acidic sites have been discussed. We could corroborate that hydroxyl groups present in silanol nests are the direct responsible of the moderate Brønsted acidity of our materials. The enhancement in the density of acidic nest silanols was reached by increasing the B content in the mesoporous structure. Finally, the use of NH 4 OH, as hydroxide source, Si/B initial molar ratio of 10 and 20 and a hydrothermal treatment of 6 days resulted the optimum synthesis conditions to obtain the highest framework B incorporation and more abundant moderate Brønsted sites (silanol nests), thus improving the potential catalytic properties of these materials. [ABSTRACT FROM AUTHOR]

In this manuscript, MCM-41 and Co-MCM-41 were synthesized to evaluate the effect of the metal incorporated in the structure of the mesoporous material used in the benzene removal in aqueous medium containing hydrogen peroxide (H 2 O 2 ). The decomposition of H 2 O 2 in the medium containing MCM-41 and Co-MCM-41 was investigated. The techniques used to characterize these materials showed satisfactory results, proving that the synthesis was effective. The decomposition of hydrogen peroxide carried out in the ultraviolet/visible molecular absorption spectrophotometer revealed that the pH of the medium and the presence of cobalt influence its decomposition. In the reaction containing benzene + Co-MCM-41 + H 2 O 2 , it was possible to confirm this information, because there was practically no decomposition at pH = 1.5, 3.0 and 5.0, whereas decomposition was considerable at pH = 7.0 and 10.0 and all H 2 O 2 was decomposed at pH = 12. Tests containing benzene + H 2 O 2 + MCM-41 resulted in a higher removal of analytes in an alkaline medium. The last catalytic tests contained benzene + Co(II) + H 2 O 2 in the aqueous reaction medium; compared to benzene + Co-MCM-41 + H 2 O 2 , it was found that the influence of Co-MCM-41 can be better viewed in pH = 10.0 and 12.0, because 82.1% of benzene was removed after 5 h. [ABSTRACT FROM AUTHOR]

A simple and effective method of miniaturized solid-phase extraction (mini-SPE) was developed for the simultaneous purification and enrichment of macrolide antibiotics (MACs) (i.e. azithromycin, clarithromycin, erythromycin, lincomycin and roxithromycin) from honey and skim milk. Mesoporous MCM-41 silica was synthesized and used as sorbent in mini-SPE. Several key parameters affecting the performance of mini-SPE procedure were thoroughly investigated, including sorbent materials, amount of sorbent and elution solvents. Under the optimized condition, satisfactory linearity (r 2  > 0.99), acceptable precision (RSDs, 0.3–7.1%), high sensitivity (limit of detection in the range of 0.01–0.76 μg/kg), and good recoveries (83.21–105.34%) were obtained. With distinct advantages of simplicity, reliability and minimal sample requirement, the proposed mini-SPE procedure coupled with ultrahigh performance liquid chromatography and quadrupole time-of-flight tandem mass spectrometry could become an alternative tool to analyze the residues of MACs in complex food matrixes. [ABSTRACT FROM AUTHOR]

Understanding the nature of copper active sites and structural evolution in preparation is crucial to rational design of copper catalysts for ethylene carbonate hydrogenation. The Cu/MCM-41 catalysts were prepared to focus on the evolution of Cu species by varying the Cu/Si mass ratio in the deposition-precipitation process. The synthesis mechanism, physicochemical properties as well as quantitative Cu active species over Cu/MCM-41 catalysts were systematically characterized and the catalytic performance was evaluated to get insight into structure–activity relationship for the ethylene carbonate (EC) hydrogenation. The results indicated that the Cu/Si ratio significantly influenced the formation of Cu 0 and Cu + active sites over the catalysts, which are derived from the CuO and Cu silicates, respectively. The appropriate textural structures, high surface Cu dispersion and synergetic effect between Cu 0 and Cu + sites of the 0.7Cu/MCM-41 catalyst resulted in an outstanding performance for EC hydrogenation, with turnover number (TON) of 18.63 and 13.82 to ethylene glycol and methanol. [ABSTRACT FROM AUTHOR]

Micro-mesoporous ZSM-5/MCM-41 composites were prepared and then loaded with varied contents of NiMoW by the wet impregnation method. The hydrocracking conversion of crude palm oil to liquid biofuels with the prepared catalysts was carried out in a batch reactor at 400°C for 2 h. ZSM-5/MCM-41 composite exhibited 51.00% conversion with a yield of 9.23% gasoline, 20.60% kerosene, and 21.17% diesel. Upon loading of NiMoW, the catalysts exhibited an improved conversion (≥ 62.60%) and a reduced formation of coke, which resulted from combined properties of ZSM-5 with MCM-41 and the presence of dispersed NiMoW. The contents of impregnated metals also affected the performance of catalysts. Using ANOVA analysis (p < 0.05), we found that 8:8:8 wt.% NiMoW-ZSM-5/MCM-41 catalyst was suitable for the production of biofuels, when considering the efficiency and cost-effectiveness. [ABSTRACT FROM AUTHOR]