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• MAL, a new method efficient to load hydrophobic materials in unmodified MCM-41 pores. • The physical state of L-Tryptophan confined into MCM-41 is nanocrystalline. • High sensitivity of LF Raman to determine the physical state of nanoconfined material. The capabilities of the recent MAL (Milling-Assisted Loading) method were analyzed for the geometric confinement of amino acids within mesoporous silica matrices. The present study has shown a high filling degree (45 wt%) of L-tryptophan into unmodified MCM-41 pores. It was shown that the low-frequency Raman spectroscopy is a suited technique to determine that molecular materials are actually confined into silica-based ordered mesoporous materials from the analysis of lattice mode region, and to probe the molecular conformation of confined materials and their interaction with the pore surface from the analysis of internal vibrations. [ABSTRACT FROM AUTHOR]

The ordered mesoporous Zr-modified MCM-41 materials were synthesized by using four different preparation methods including impregnation method, precipitation method, ultrasound method and trituration method, respectively; active zinc species were immobilized on the modified materials with different methods for introducing zirconia species as effective catalysts for the acetylene hydration. All the synthesized materials were characterized by various techniques including BET, FTIR, XRD, TGA, TEM, XPS, NH 3 -TPD, H 2 -TPR, and solid-stated UV–vis. The correlation between structural properties of zirconia modified support and catalytic performance of the Zn catalysts was evaluated in detailed in the acetylene hydration. It is demonstrate that the Zr-modified materials showed the excellent thermostability, and zirconia species addition could enhance the interactions between active metal and support, as well as control the metal particles size with better dispersion. In addition, the substantial enhancement of acid sites and total acid quantity for the modified materials were contributed to the zirconia species addition. Besides, activity evaluation confirms that the Zn/ZM-P catalyst showed more optimistic catalytic performance above 92% C 2 H 2 conversion and 85% selectivity to acetaldehyde in the acetylene hydration due to the stronger metal-support interactions and more acid sites. The study would provide scientific basis for the design of metal catalysts. [Display omitted] • Zr-modified MCM-41 materials were synthesized by different preparation methods. • The correlation between structural properties of Zr-MCM-41 and catalytic performance of the catalysts was evaluated. • Zr-modified MCM-41 markedly improved catalytic performance of Zn catalyst. • Zr-modified MCM-41 enhanced stronger metal–support interactions, provided more acid sites and active sites. [ABSTRACT FROM AUTHOR]

[Display omitted] • The adsorption of sorbent for thiophene was accompanied by S-Ag and π complexation. • Ag-O-Si is the main active center for adsorption of thiophenic compounds. • Charge density of sulfur atom affects S-Ag bond between thiophenic compounds and Ag. Zeolites and some mesoporous materials modified by Ag possess excellent desulfurization performances toward the adsorption of thiophenic compounds. However, Ag in Ag-based sorbents has different forms, and the interactions between different forms of silver and thiophene still require further studies. In this paper, pure silica SBA-15 and MCM-41 mesoporous materials with weak acidity were loaded with Ag from the silver ammonia solution to form Ag/SBA-15 and Ag/MCM-41 sorbents. By comparing the desulfurization efficiencies of the sorbents in the simulated solution of thiophene-cyclohexane, thiophene-benzene, tetrahydrothiophene-cyclohexane and tetrahydrothiophene-benzene, it is found that the adsorption of sorbent for thiophene was accompanied by S-Ag and π complexation, and the adsorption performances of thiophene by the sorbents were greatly affected by benzene. The XPS results show that most Ag in Ag/SBA-15 and Ag/MCM-41 sorbents was metallic Ag, and some Ag strongly interacting with the carrier led to the formation of Ag-O-Si bonds as the main active center of thiophenic compounds. In addition, the sulfur atomic mulliken charges (e-) of different thiopheic compounds (thiophene, tetrahydrothiophene, methylthiophene) will affect the interactions between active components Ag and thiophene sulfur compounds. The desulfurization efficiencies of the sorbents in thiophene-cyclohexane, 2-methylthiophene-cyclohexane, and 3-methylthiophene-cyclohexane showed that the decrease in mulliken charges (e-) of sulfur atoms facilitated the S-Ag bond interaction between the sulfur atom of thiophenic compounds and active component in the sorbent. In conclusion, to obtain the Ag-based sorbent with good adsorption performance for thiophenic compounds, the carrier should contain a certain content of silicon hydroxyl and the suitable pore structure. During the preparation of SBA-15 and MCM-41 mesoporous materials modified by Ag, the Ag-O-Si bonds are more easily formed when silver ammonia interacts with the silicon hydroxyl group on the surface of the carrier. The suitable pore size can inhibit agglomerate to form metallic Ag during the calcination process. These conclusions will provide theoretical guidance for the preparation of silver-based sorbents for thiophene. [ABSTRACT FROM AUTHOR]

Highlights: [•] Aluminum incorporation has rendered the template/matrix interactions stronger. [•] SCCO2 extraction efficiencies decrease as the matrix Al/Si molar ratio increases. [•] Well-performed methanol has resulted in extraction efficiencies of 60–87%. [•] Modifiers and Al/Si ratio both strongly affect the materials structural properties. [•] Samples treated by SCCO2/acetic methanol seem to be more catalytically active. [Copyright &y& Elsevier]

Zirconia modified mesoporous molecular sieve MCM-41 supports were prepared by hydrothermal synthesis method, in situ synthesis method and precipitation method. Ruthenium and lanthanum supported on MCM-41 and zirconia modified MCM-41 catalysts were prepared via two solvents impregnation method. The catalysts were characterized by X-ray diffraction, transmission electron microscopy, nitrogen adsorption-desorption, and water/benzene static adsorptions techniques. It has been found that Ru-La supported on MCM-41 modified with zirconia by hydrothermal synthesis method (Ru-La/ZrO2-MCM-41-HS) leads to the biggest increase of the hydrophilicity. Ru-La/ZrO2-MCM-41-HS catalyst with the highest hydrophilicity shows the best performance in liquid phase hydrogenation of benzene to cyclohexene. [ABSTRACT FROM AUTHOR]

Abstract: Composing of both zeolite and mesoporous structures, micro/mesoporous composites exhibit promising CO2 capture capabilities. In this work, a full-atomic mimetic 5A-MCM-41 structure with bimodal pores has been constructed, in which the microporous structure of 5A zeolite is constructed and optimized based on zeolite A with Ca and Na cations introduced; whereas the mesoporous MCM-41 structure is produced by caving the cylindrical pores in the obtained 5A zeolite matrix. CO2 adsorption on 5A-MCM-41 has been simulated by the grand canonical Monte Carlo (GCMC). The simulation results demonstrated that CO2 is preferentially adsorbed in micropores, and the CO2 adsorption capacity and its isosteric heat on 5A-MCM-41 are much larger than those of N2. The CO2 selectivity of 5A-MCM-41 results from the electrostatic interaction of the quadrupole CO2 molecule with Ca2+ cations of the zeolite. Furthermore, the hierarchical micro/mesoporous composites are synthesized to verify the simulated predictions. By the hydrothermal reaction using 5A zeolite “seeds” as the silicon source and hexadecyl trimethylammonium bromide (CTAB) as the mesoporous template, 5A-MCM-41 composites are obtained, the characteristic results show that typical 5A microporous structure is remained and disordered mesoporous networks are produced in the composites. Moreover, the CO2 adsorption capacity of the 5A-MCM-41 composites can reach as high as 4.08 mmol/g at 100 kPa and 298 K. These observations have been strongly supported that micro/mesoporous composites with metal ions located would be promising adsorbents for CO2 separation. [Copyright &y& Elsevier]

Abstract: Mesoporous molecular sieves MCM-41 and bulk 12-tungstophosphoric acid (HPW) were synthesized and employed to prepare 5–45 wt.% HPW/MCM-41 mesoporous materials. Characterization results suggested the good dispersion of HPW within MCM-41 when the loading of HPW was less than 35 wt.% and HPW/MCM-41 retained the typical mesopore structure of the supports. The results of the catalytic oxidation of benzaldehyde to benzoic acid with 30% H2O2, in the absence of any organic solvent and co-catalysts, indicated that HPW/MCM-41 was an efficient catalyst and 30 wt.% HPW/MCM-41 sample exhibited the highest catalytic activity among these materials. [Copyright &y& Elsevier]

The phosphine-free heterogeneous coupling of acyl chlorides with terminal alkynes was achieved in triethylamine at 50 °C in the presence of a 0.2 mol% 3-(2-aminoethylamino)propyl-functionalized MCM-41-immobilized palladium complex [MCM-41-2N-Pd(OAc)2], yielding a variety of ynones in good to excellent yields. This novel heterogeneous palladium catalyst can be conveniently prepared from commercially available and cheap reagents and recycled by a simple filtration of the reaction solution, and used for at least 10 consecutive trials without any decrease in activity. Our system not only avoids the use of phosphine ligands, but also solves the basic problem of palladium catalyst recovery and reuse. [ABSTRACT FROM AUTHOR]

Abstract: The supported LaNiO3 perovskite catalysts on mesoporous carrier (LaNiO3/SBA-15, LaNiO3/MCM-41 and LaNiO3/SiO2) with different pore structures have been synthesized via filling the pores of mesoporous silica with citrate complex precursors of nickel and lanthanum, with further treatments. The catalysts were characterized by means of N2 physisorption, XRD, HRTEM+EDX, TPR, temperature-programmed hydrogenation (TPH) and TGA techniques, and their catalytic performances were measured in methane dry reforming with carbon dioxide to hydrogen and synthesis gas (syngas). The results of low-angle XRD, N2 physisorption and TEM analysis showed that LaNiO3 perovskite was formed inside the channels of mesoporous supports, and the introduction of LaNiO3 perovskite did not destroy the mesoporous structure of support. The pore structure had a substantial influence on the catalytic performance. LaNiO3/MCM-41 exhibited the higher initial catalytic activity, owing to the higher Ni dispersion, while LaNiO3/SBA-15 was superior to LaNiO3/MCM-41 in the long-term stability, which could be due to the stable silica matrix restricted the agglomeration of nickel species. The hexagonal mesopores of LaNiO3/SBA-15 were still kept intact after reaction, while the mesoporous structure in LaNiO3/MCM-41 was collapsed during the reaction, which resulted in metal particles aggregation to certain extent. For comparison, the carbon deposition was responsible for the remarkable decrease of catalytic activity over LaNiO3/SiO2 sample, evidenced by TGA and TPH results. [Copyright &y& Elsevier]

Abstract: MCM-41 type materials containing Al and Ga (Al–Ga-MCM-41) were prepared by a synthesis gel using cethyltrimethylammonium chloride as surfactant. In the preparation, Si/(Al+Ga) ratios were 21, 27 and 32 in the gel, maintaining the concentration of Al constant. The structures of the materials were characterized by X-ray diffraction (XRD), nitrogen physisorption, Fourier transform infrared spectroscopy (FTIR) of adsorbed pyridine, 27Al MAS NMR, 29Si MAS NMR and energy dispersive analysis of X-ray (EDX). Al–Ga-MCM-41 exhibited prominent characteristics as supports for the Ni–Mo–S type catalysts used in the hydrodesulfurization of 4,6-dimethyldibenzothiphene (4,6 DMDBT). The presence of Ga was detected by TEM with a resolution of 1.9Å point to point; therefore the Ga is in the lattice. The amount of Ga in the support enhanced the activity of the catalysts and modified the products distribution. The maximum catalytic activity and direct desulfurization capability was achieved on the catalyst NiMo/Al–Ga-MCM-41 with Si/(Al+Ga)=32 molar ratio. [Copyright &y& Elsevier]

A ternary nanocomposite of graphene/polyaniline (PANI)/porous silica MCM-41 (MCM-41) was prepared by a hydrothermal method. The amount of graphene oxide (GO) in the graphene/PANI/MCM-41 nanocomposite had a strong effect on the supercapacitor performance. The experimental results showed that the specific capacitance of the graphene/PANI/MCM-41 nanocomposite could reach the highest value when the GO content was 50%. The specific capacitance of the nanocomposite was 405 F g−1 at a current density of 0.8 A g−1. Furthermore, over 91.4% of the original capacitance was retained after repeating the galvanostatic charge–discharge for 1000 cycles. The performance of the prepared supercapacitor containing different amounts of GO were studied in detail. [ABSTRACT FROM AUTHOR]

Nano-ordered MCM-41 anchored sulfonic acid (MCM-41- SO 3 H) was used as an efficient heterogeneous catalyst for the synthesis of Schiff bases by the reaction of different aryl/alkyl aldehydes or ketones with primary amines at room temperature with high to excellent yields. This mesoporous catalyst can be reused at least four times without significant loss to its catalytic potential. [ABSTRACT FROM AUTHOR]

Abstract: The formation process of MCM-41 containing zeolite Y building units has been investigated by UV Raman spectroscopy, 29Si and 27Al MAS NMR spectroscopy, X-ray diffraction (XRD), N2 adsorption and electron microscopy (SEM and TEM). It is found that the precursor containing zeolite Y secondary building units promotes the formation of a metastable mesopore structure just after mixing the zeolite precursors with CTAB. In contrast, the low-polymerized aluminosilicates and well-crystallized zeolite crystals cannot be assembled with CTAB at this stage. The result supports that the zeolite secondary building units should promote to the formation of the mesopore wall. This has been ascribed to its high anionic charge density as well as the appropriate multidentate coordination. Lowering down the pH value to 9.3 facilitates the further polymerization of the aluminosilicate species to build up a stable mesoporous phase. [Copyright &y& Elsevier]

Effect of pristine and modified MCM-41 on the kinetics of styrene atom transfer radical polymerization (ATRP) was studied using a double bound containing modifier at 110°C. Conversion, molecular weight and PDI were obtained during the polymerization reactions to study the polymerization kinetics. Addition of the both types of MCM-41 has resulted in inconsiderable variations on the kinetics of polymerization. A similar trend is observed for the molecular weight of the free chains; however, increasing MCM-41 content results in higher PDI values. Also, surface modification of MCM-41 results in lower polymerization rates. In the case of grafted chains, molecular weight and PDI values increase by increasing MCM-41 content. Polystyrene-coated MCM-41 nanoparticles were synthesized by ATRP. Effect of surface modification on the kinetics of ATRP was also investigated. [ABSTRACT FROM AUTHOR]

Recently, amine-functionalized mesoporoussilica materials haveattracted considerable attention as a promising chemical sorbent forpostcombustion CO2capture applications. However, the graftingof amines in the conventional MCM-41 support induces the subsequentreduction of surface area and pore volume of the sorbents, affectingthe CO2adsorption–desorption kinetics significantly.To mitigate this problem, expensive pore expansion agents have beenused to increase the pore size as well as the pore volume. The presentstudy provides an innovative approach to the development of novelpore-expanded MCM-41 without the application of any swelling agent.The average pore size (∼30 nm) obtained in our work is remarkablyhigher than the values (9 to 10 nm) reported in the literature. Onthe basis of the fundamental understanding of micelle properties underdifferent alkaline conditions, a mechanism for the pore expansionprocess is proposed. The outcome (1.2 mmol/g) of the preliminary CO2adsorption studies carried out on the novel support materialgrafted with monoamine silane is very promising. [ABSTRACT FROM AUTHOR]

ZSM-5/MCM-41 zeolite composites with varying mesopore sizes were prepared through alkali-desilication and surfactant-directed recrystallization with different chain length of alkyltrimethylammonium bromide. XRD and TEM revealed that the composites possessed the characteristics of both ZSM-5 and mesoporous MCM-41 with hexagonal symmetry. N-adsorption-desorption, Al MAS NMR, NH-TPD and in situ FT-IR results suggested that the sizes of the mesopores and the accessibility of acid sites could be affected greatly by the chain length of alkyltrimethylammonium bromide used. Catalytic cracking of n-dodecane over ZSM-5/MCM-41 composites was studied in the form of coatings on the inside of a tubular reactor at 550 °C and 4 MPa. The conversion of n-dodecane increased gradually with increasing the mesopore sizes of ZSM-5/MCM-41 composites, implying a positive effect of the mesopores on the diffusion inside pore channels and the accessibility of acid sites by the reactants. Graphical Abstract: [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Nanoporous materials such as Mobil composite material number 41 (MCM-41) are attractive for applications such as catalysis, adsorption, supports, and carriers. Green synthesis of MCM-41 is particularly appealing because the chemical reagents are useful and valuable. We report on the eco-friendly synthesis of MCM-41 nanoporous materials via multi-cycle approach by re-using the non-reacted reagents in supernatant as mother liquor after separating the solid product. This approach was achieved via minimal requirement of chemical compensation where additional fresh reactants were added into the mother liquor followed by pH adjustment after each cycle of synthesis. The solid product of each successive batch was collected and characterized while the non-reacted reagents in supernatant can be recovered and re-used to produce subsequent cycle of MCM-41. The multi-cycle synthesis is demonstrated up to three times in this research. This approach suggests a low cost and eco-friendly synthesis of nanoporous material since less waste is discarded after the product has been collected, and in addition, product yield can be maintained at the high level. [ABSTRACT FROM AUTHOR]

Abstract: Catalytically active heterogeneous catalysts have been prepared via microwave deposition of iron oxide nanoparticles (0.5–1.2wt%) on MCM-41 type silica materials with different morphologies (particles, helical and spheres). This methodology leads to iron oxide nanoparticles composed by a mixture of FeO and Fe2O3 species, being the Fe(II)/Fe(III) peak ratio near to 1.11 by XPS. DRUV spectroscopy indicates the presence of tetrahedral coordinated Fe3+ in the silica framework of the three catalysts as well as some extraframework iron species in the catalysts with particle and sphere-like morphologies. The loading of the nanoparticles does neither affect the mesopore arrangement nor the textural properties of the silica supports, as indicated by SAXS and nitrogen adsorption/desorption isotherms. A detailed investigation of the morphology of the supports in various microwave-assisted catalyzed processes shows that helical mesostructures provide optimum catalytic activities and improved reusabilities in the microwave-assisted redox (selective oxidation of benzyl alcohol) catalyzed process probably due to a combination of lower particle size and higher acidity in comparison with the supports with particle and sphere morphology. [Copyright &y& Elsevier]

In this work, MCM-41 (Mobil Composition of Matter number 41) nanoporous silica has been synthesized and characterized by X-ray powder diffraction and IR spectroscopy. In the next step, poly-thiophene was coated on the nanoporous silica in order to increase its surface area. This composite was characterized by X-Ray powder diffraction, High resolution transmission electronic microscopy micrograph (HRTEM), elemental analysis (CHNS) and Thermal analysis (TG/DTA). The application of this composite was investigated in mercury ions removal from waste water prior to determination by inductively coupled plasma atomic emission spectroscopy (ICP-OES). In order to investigate the effect of nanoporous structure on the efficiency of this composite, the same composite without porous structure has been synthesized and the results were compared. [ABSTRACT FROM PUBLISHER]

Abstract: A series of MCM-41 samples containing molybdenum oxide as active species in the mesoporous channels loaded by spontaneous monolayer dispersion (SMD) and impregnation (IM) have been prepared and characterized using XRD, N2 adsorption–desorption analysis, Fourier transform infrared spectroscopy (FTIR) and intelligent gravimetric analyzer (IGA). The relative number of hydroxy on the adsorbents was investigated by in situ FTIR. Surface acidities of the adsorbents were studied by infrared spectroscopy of adsorbed pyridine and correlated with reactivity for adsorptive desulfurization. The IGA technique was employed to investigate adsorption behavior of thiophene and benzene on the adsorbents at 303K. It is shown that MoO3 can be highly dispersed up to 0.2gg−1 in the MCM-41 channels by the SMD strategy with the ordered mesoporous structure of the MoMM samples remaining intact. The ordered mesostructure of MCM-41 is, however, destroyed at higher MoO3 contents of 0.26 and 0.32gg−1 with particle sizes of 1.2nm and 3.6nm, respectively, observed. For the MoMI(0.2) sample prepared by the IM method, the aggregation of the MoO3 particles takes place with a particle size of 6.5nm obtained. The results are also revealed that the dispersion extent of the MoO3 species is related to the abundant surface hydroxy of MCM-41. The host species and guest species undergo solid-state reaction to form Sih name="sbnd" />Mo bonds in the mixtures which enhance both the Lewis acid and Brönsted acid of the samples. It has been concluded that the surface acidities of the sorbents contributes to the desulfurization performance which has also been investigated in this study. The octahedral coordinated species (Mo7O24 6−) are the adsorptive active species for desulfurization compared with the tetrahedral coordinated ones (MoO4 2−). [Copyright &y& Elsevier]

Abstract: Acylals were prepared by direct condensation of aldehydes with acetic anhydride using nano-ordered MCM-41-SO3H as a heterogeneous catalyst under solvent-free conditions at room temperature in a very short reaction time and excellent yields. The catalyst is recyclable, non-toxic, neither air nor moisture sensitive, and easy to handle. High chemoselectivity toward aldehydes in the presence of ketones is another advantage of the present method which provides selective protection of aldehydes in their mixtures with ketones. [Copyright &y& Elsevier]

Abstract: Cerium-doped MCM-41 (Ce-MCM-41) was prepared by a hydrothermal method and its catalytic activity for ozonation of p-chlorobenzoic acid (p-CBA) in aqueous solution was studied. For comparison, cerium-loaded MCM-41 (Ce/MCM-41) was prepared by a dipping method. Ce-MCM-41 was characterized by the low and wide angle X-ray powder diffraction (XRD), nitrogen adsorption–desorption, transmission electron microscopy (TEM) and ultraviolet–visible diffuse reflection spectrum (UV–vis DRS). The results showed that the material retained the highly ordered mesopore structure of MCM-41 and had a surface area of 852m2 g−1. Cerium was incorporated into the framework of MCM-41, locating at tetrahedrally coordinated sites. The cerium doping content, initial pH of aqueous solution and reaction temperature played important roles in catalytic ozonation of p-CBA. Under the chosen conditions (1.39mgl−1 ozone dosage, 10mgl−1 p-CBA solution and 1gl−1 catalyst dosage), the high mineralization rate (86%) was achieved by Ce-MCM-41/O3 process at 60min reaction time, only 52% by O3 alone. The combination of Ce-MCM-41 and O3 exhibited a significant synergetic effect. Ce-MCM-41 showed the better activity and stability than cerium-loaded MCM-41(Ce/MCM-41) during catalytic ozonation of p-CBA, its cerium leaching was greatly reduced (only 0.085mgl−1) and below detection limit after being reused, compared with that of Ce/MCM-41 (0.44mgl−1) with the presence of the same theoretical cerium content. TOC removal rate slightly decreased from 86% to 81% and kept stable after Ce-MCM-41 being re-utilized two times, which illustrated that Ce-MCM-41 was a kind of promising catalyst for ozonation of p-CBA. The addition of Ce-MCM-41 significantly improved ozone decomposition into HOus solution and reduced ozone concentration in equilibrium. [Copyright &y& Elsevier]

Nanosized MCM-41-SO3H material based on ordered mesoporous silica gel with covalently attached sulfonic acid groups was synthesized and used as acid catalyst for green synthesis of 2-substituted benzimidazole derivatives. Echo-friendly protocol, short reaction times, easy and quick isolation of the products, and excellent yields are the main advantages of this procedure. [ABSTRACT FROM AUTHOR]

Abstract: Mesoporous MCM-41 and Fe loaded MCM-41 (Fe/MCM-41), which were prepared by hydrothermal and dipping method respectively, were applied as heterogeneous catalysts for the ozonation of p-chlorobenzoic acid (p-CBA) in aqueous solution. MCM-41 and Fe/MCM-41 were characterized by low and wide angle XRD, atomic absorption spectrometer (AAS) and N2 adsorption–desorption techniques. Due to the synergetic effect, Fe/MCM-41/O3 process significantly improves p-CBA and total organic carbon (TOC) removal efficiency compared to ozonation alone. Under the experimental condition, TOC removal efficiency of Fe/MCM-41/O3 process is over 94.5% at 60min oxidation time, only 61.5% by MCM-41/O3 process, 62.3% by O3 alone process. Fe/MCM-41/O3 process follows apparent first-order kinetics, while ozonation alone, MCM-41/O3 and Fe2O3/O3 processes follow apparent second-order kinetics. The presence of tert-butanol (TBA) in the Fe/MCM-41/O3 process indicated that the oxidation mechanism of p-CBA occurs via liquid bulk. Fe/MCM-41 is a promising catalyst for the ozonation process of p-CBA. [Copyright &y& Elsevier]

Abstract: CoO and Co3O4 nanoparticles were uniformly dispersed inside mesoporous MCM-41 and Al-MCM-41 supports using supercritical CO2 reactive deposition. This method represents a one-pot reproducible procedure that allows the dissolution of the organocobalt precursor and supports impregnation in supercritical CO2 at 70°C and 110bar, followed by the precursor thermal decomposition into cobalt species at 200°C and 160bar. By the relative concentration of the cobalt precursor [cobalt (II) bis (η5-ciclopentadienil)], the load of cobalt nanoparticles was controlled and then determined by Inductively Coupled Plasma (ICP-OES). The synthesis of CoO and Co3O4 species inside the MCM-41 and Al-MCM-41 substrates was confirmed by X-ray Photoelectron (XPS) and Laser Raman Spectroscopies (LRS). By N2 adsorption and Small Angle X-ray Scattering (SAXS), it was determined that the hexagonal arrangement as well as the surface area and pore size of the substrates changed after the addition of cobalt. By means of X-ray mapping from SEM images, a homogeneous distribution of cobalt nanoparticles was observed inside the mesopores when the cobalt loading was 1wt.%. In addition, spherical cobalt nanoparticles of average diameter close to 20nm were detected on the outer surface of MCM-41 and Al-MCM-41 supports when the cobalt content was higher. On the other hand, by Transmission Electron Microscopy (TEM), it was possible to measure the interplanar distance of the crystalline plane of the outer nanoparticles, which was later compared with the theoretical distance values which allowed identifying the CoO and Co3O4 phases. [Copyright &y& Elsevier]

MCM-41 and Al-MCM-41 has been synthesized using cetyl-trimethylammonium bromide (CTAB) surfactant as template and adding the silica precursor to aqueous solutions containing CTAB. The obtained solids were calcined at 600 °C for 4 h. HPW heteropolyacid supported on the mesoporous were prepared using the incipient wetness method. The characterization of materials was performed by X-ray diffraction, Transmission Electron Microscopy, N adsorption, Si Cross Polarization-Magic Angle Spinning and Al MAS NMR. Results showed that the hexagonal structure is obtained in both cases. The Aluminium species are located inside an extra-framework. The impregnation reduces the surface area of the mesoporous materials especially of the Al-MCM-41 suggesting a participation of aluminium during the impregnation. HPW is well dispersed in the mesoporous materials and is located inside the pores interacting with the silanol group of the pores wall. Al MAS NMR measurements have showed that the impregnation causes the removal of the non-framework aluminium. [ABSTRACT FROM AUTHOR]

Nanocrystalline titanium dioxide, TiO2, is a well studied and commonly used material for photocatalytic applications. However, the control of particle size, monodispersity, large catalytic surface for sufficient adsorption of organic pollutants, recovery and recycle of TiO2 nanoparticles are challenging tasks. Hence in this work, titania has been introduced into the nanopores (2-10 nm size) of MCM-41 to produce stable nanoparticles of uniform size and shape. Further, the photocatalytic efficiency can be improved by lengthening the life time of the excited electrons/holes during photoreaction. This could be achieved by incorporating molybdenum in to the MCM-41 silica matrix in addition to titania loading. In the present study, the synthesis and the photocatlaytic efficiency of a new photocatalyst TiO2@Mo-MCM-41 (25 wt.% TiO2 loaded Mo incorporated MCM-41) are reported. Mo-MCM-41, with different ratios of Si to Mo(Si/Mo = 25,50,75), is synthesized by hydrothermal method and loaded with 25 wt.% TiO2 using sol-gel method. The photocatalytic activity of the prepared samples was evaluated using methyl orange as a model organic compound. X-ray diffraction (XRD), Transmission Electron Microscopy (TEM) and nitrogen adsorption-desorption isotherm (BET analysis) measurements were used to investigate the effects of the incorporated elements in the structure of MCM-41. It was found that the photodegradation ability of 25% TiO2 loaded Mo-MCM-41 was highly related to the amount of Mo atoms present in the sample with the optimum atomic ratio of Si to Mo being 50. [ABSTRACT FROM AUTHOR]

Titanium tetra-isopropoxide reacts with the silanol groups of MCM41 calcined at two different temperatures, 550 and 750°C, to form well-defined surface organometallic species. For MCM41 calcined at 550°C, the amount of available silanol allows mainly the formation of the bipodal titanium complex, (≡SiO)2Ti(OiPr)2, while calcination at 750°C leads to the formation of the monopodal titanium complex ≡SiO-Ti(OiPr)3. Ti-MCM41(750) was found to be more active and selective in the oxidation of sulfides, compared to Ti-MCM41(550), and this can be attributed to the development of a large amount of tetrahedral isolated titanium (IV) which seems to be the active site in this reaction. In the asymmetric oxidation of sulfide by H2O2, Ti-MCM41(750) was found also more reactive than Ti-MCM41(550), since it develops the singly bonded titanium species, ≡SiO-Ti(OiPr)3, which appears to be the chiral active site in this reaction. [ABSTRACT FROM AUTHOR]

Dibenzothiophene sulfone, one of the products of the oxidative desulfurization of heavy oil, can be utilized through catalytic cracking. The object of the present study is to provide Cs/MCM-41 catalysts for the removal of sulfur dioxide from dibenzothiophene sulfone. Cesium oxide was deposited via an impregnation method on MCM-41, and the catalytic performances of the samples were investigated during the deoxydesulfurization of dibenzothiophene sulfone to biphenyl and sulfur dioxide gas. The influence of cesium loading on the basic properties of MCM-41 was estimated by the temperature-programmed desorption of carbon dioxide. The dibenzothiophene sulfone conversions of the MCM-41, Cs(1 wt%)/MCM-41, Cs(3 wt%)/MCM-41 and Cs(10 wt%)/MCM-41 catalysts were 38.5, 52.1, 72.4 and 40.9%, respectively, which implies that the Cs(3 wt%)/MCM-41 catalyst has the highest activity. This result agrees with the finding of the basicity enhancement of MCM-41 with the addition of cesium, in which Cs(3 wt%)/MCM-41 exhibited a maximum number of basic sites. [ABSTRACT FROM AUTHOR]

MCM-41 and FSM-16 were both prepared using no hydrothermal conditions, and nickel was doped into these catalysts (Ni-MCM-41 and Ni-FSM-16) using a template ion exchange method. FSM-16 and Ni-FSM-16 had greater catalytic activity for the conversion of ethanol than MCM-41 and Ni-MCM-41, indicating that FSM-16 has potential as a catalyst for the conversion of ethanol to propylene. [ABSTRACT FROM AUTHOR]

[Display omitted] • Ti anchored MCM-41 material is synthesized by modified process. • The synthesized Ti-MCM-41 is characterized by various spectroscopic techniques. • Modified Ti-MCM-41/GCE shows excellent sensing properties with uric acid. • The sensitivity of modified Ti-MCM-41/GCE with UA is up to nano-molar scale. • The results are in good agreement in the real sample analysis and reproducible. A simple and modified synthetic strategy has been developed for the preparation of Ti(IV) anchored mesoporous MCM-41 material from the commercially available starting material of titanocene dichloride and MCM-41. The vacuum diffusion process has been utilized for anchoring Ti(IV) on MCM-41 (Ti-MCM-41) via surface activation instead of the chemical activation process. The modified Ti-MCM-41/glassy carbon electrode (GCE) was developed from Ti-MCM-41 and evaluated for the selective sensing of mammalian metabolic bio-marker of uric acid (UA) by the electrochemical method. The modified electrode (Ti-MCM-41/GCE) shows an excellent selective electrochemical response with UA, good linear competence in wide range concentrations (10–110 nM) and scan rates (50–900 mV s−1) and a low limit of detection up to 2.98 nM in the category of silica based mesoporous material. The selectivity and sensitivity of the electrode were tested with various potential organic interferents that exhibit good anti-interferents activity. The proposed modified electrode is potentially useful for commercial sensing application of UA since the analysis of human urine samples under various age people are good agreements with recovered UA by the standard addition method. The stability and reproducibility of the Ti-MCM-41/GCE were tested and the results are reproducible in a number of electro-catalytic cycles. [ABSTRACT FROM AUTHOR]

• MCM-41 was prepared from liquid crystal display waste glass and chemical mechanical polishing sludge via hydrothermal treatment. • Effect of different temperatures and liquid–solid ratio on the microstructure humidity control performance of MCM-41 were studied. • The environmental humidity control and high performance of the materials were observed. • The effective synthesis of mesoporous materials from photovoltaic industry waste was developed. In this work, aluminum-containing MCM-41 mesoporous materials (ACMCM-41) were successfully prepared from liquid crystal display (LCD) waste glass and chemical mechanical polishing (CMP) sludge by a novel route for the reused of industrial waste. It can be inferred from the increase in the surface area, the introduction of an appropriate amount of aluminum retained the ordered mesoporous structure of the ACMCM-41 during the hydrothermal treatment process. Larger pore volume and specific surface area, as well as a great deal of mesopores distributed in the range of 3–20 nm can greatly contribute to the improvement of humidity control performance. ACMCM-41 was tested for its average equilibrium moisture content under different relative humidity of the material under water vapor adsorption/desorption. ACMCM-41 showed excellent humidity control performance (61.18 m3/ m3). The possibility of synthesis zeolite from the residual solid after aged was also discussed. The residual solids can be reused as suitable raw material for the synthesis of zeolite. [ABSTRACT FROM AUTHOR]

NiMo catalysts supported on mesoporous MCM-41 type materials shaped with binder were tested for activity in the hydrodesulfurization of 4,6-dimethyldibenzothiophene (4,6-DMDBT) and the diesel fuel fraction (0.92 wt% of sulfur). The aim of the investigation was to evaluate the effect of ion exchange with protons of Al- or Ti-substituted MCM-41 mesoporous supports. The subjected catalytic systems were NiMo/HAlMCM-41 and NiMo/HTiMCM-41, and for comparison purposes NiMo/AlMCM-41 and NiMo/TiMCM-41. The samples were characterized by N2 sorption (at 77 K), XRD, TEM, XPS, SEM and Py–IR. It was found that the functionalization of AlMCM-41 and TiMCM-41 with protons increased the conversion of 4,6-DMDBT and the pseudo-first-order rate constant. Correspondingly, 4,6-DMDBT HDS reactions over the NiMo/HTiMCM-41 catalyst proceeded to a similar extent via hydrogenation and direct desulfurization, whereas over the NiMo/HAlMCM-41 they proceeded mainly via direct desulfurization. Furthermore, the ion-exchanged catalysts displayed two-fold higher efficiency in direct desulfurization than their non-modified counterparts. The NiMo/HTiMCM-41 catalyst exhibited the highest catalytic efficiency in the HDS of 4,6-DMDBT and the diesel oil fraction. The high activity of the NiMo/HTiMCM-41 catalyst is mainly attributed to its appropriate acidity, as well as the metal–support interaction providing both the high dispersion of the active phase and the desirable multilayered stacking morphology of the active phase slabs. [ABSTRACT FROM AUTHOR]

A heterogeneous catalytic system (unfunctional mesoporous material MCM-41), which efficiently promoted one-pot synthesis of spiro[indoline-3,2′-pyrrolidin]-ones, has been developed. Under mild reaction conditions, a series of spiro[indoline-3,2′-pyrrolidin]-ones derivatives were synthesized in good yields (up to 95%) in water/ethanol = 2/1 as solvent. Notably, the unfunctional MCM-41 catalyst could be easily recovered by centrifugation and reused at least 10 times without loss in activity. And the scale up experiments also demonstrated the practicability of the catalystic system. Reusability, operational simplicity and eco-friendly are highlight of this study. [Display omitted] [ABSTRACT FROM AUTHOR]

The aim of this work is the optimization of the operating conditions under which MCM-41-mesoporous material can be incorporated into polyethersulfone (PES)/MCM-41 membranes for nanofiltration (NF) applications. MCM-41 mesoporous material mixed matrix PES membranes have the potential to reduce membrane fouling by organic dye molecules. Process optimization and modeling aim to reduce wasted energy while maintaining high flow during the operation to handle the energy efficiency problems membranes often have. An optimization technique was applied to obtain optimum values for some key parameters in the process to produce a certain amount of flux above the desired values. Response surface methodology (RSM) and analysis of variance (ANOVA) were used as mathematical and statistical analyses to improve the performance of the process on a larger scale. This work investigated the influence of the operating parameters, such as the feed pH values (3–11), MCM-41 content (0–1 wt.%), and the feed dye concentration (10–100 ppm) for each of the two studied dyes, acid black 210 (AB-210) and rose bengal (RB), and their interactions on the PES membrane permeability. The results showed that the PES membrane had the best performance at 64.25 (L·m−2·h−1·bar-1) and 63.16 (L·m−2·h−1·bar-1) for the AB-210 and RB dyes, respectively. An MCM-41 content of nearly 0.8 wt.% in the casting solution, feed dye concentration of 10 ppm for the studied dyes, and feed pH of 3 for the RB dye was found to be the optimal parameters for eliciting the response. The pH had no significant influence on the response for the AB-210 dye, while the pH shows some minor effects on response with the RB dye, and the Pareto chart of the standardized effects on the permeation flux of both dyes using statistically significant at the 5% significance level support these results. [ABSTRACT FROM AUTHOR]

V-doped TiO2 quantum dots (QDs) possessing many Ti3+ defects were fabricated by simple hydrolysis using MCM-41 as a support. The QDs show high charge-separation efficiency and high photocatalytic activity due to the quantum size effect and the newly formed defect- and dopant-mediated band levels. [ABSTRACT FROM AUTHOR]

The mesoporous material MCM-41 was amino-modified with 3-aminopropyltriethoxysilane, and the amino content of modified MCM-41 was 0.16 mmol/g. Then G-MCM-41 was prepared by adding glutaraldehyde. Candida antarctica lipase B (CALB) was immobilized on G-MCM-41 at 45 °C for 5 h to obtain immobilized lipase G-MCM-41-CALB. The lipase protein loading of G-MCM-41-CALB was 87.4 mg/g and its expressed activity was 80.2%. The immobilization efficiency of G-MCM-41-CALB reached 93%. The characterization of G-MCM-41-CALB showed that the mesopores maintained the pore structure, the crystal surface was intact, and the pore size became smaller, indicating that the CALB was immobilized on the carrier. The optimum pH and temperature of G-MCM-41-CALB were 7.0 and 50 °C, respectively. The relative activity of G-MCM-41-CALB was still >50% after 40 days at 4 °C. The thermal stability of G-MCM-41-CALB was improved compared to free CALB. G-MCM-41-CALB was evaluated for its ability to catalyze the transesterification of soybean oil and phytosterol. Results showed a conversion rate of 87.4% and the relative activity of G-MCM-41-CALB was 83% after 7 reuses. • CALB was covalently immobilized on G-MCM-41 to obtain immobilized lipase. • G-MCM-41-CALB lipase loading and activity were 87.4 mg/g and 1.18 103 U/g, respectively. • Characterization of G-MCM-41-CALB showed that the mesopores kept their structure. • The thermal stability of G-MCM-41-CALB was improved compared to free CALB. • The relative activity of G-MCM-41-CALB after 7 times of repeated use was 83.0%. [ABSTRACT FROM AUTHOR]

Although nanoporous shape-stabilized composite phase change materials (PCMs) could efficiently address the leakage issue of pure PCMs during the solid-liquid phase transition process, numerous experiments have verified that the thermophysical parameters of the nanoporous shape-stabilized composite PCMs are significantly different from those of macroscopic bulk PCMs due to the nanoconfinement effects. However, macroscopic experimental data cannot directly reflect the microscopic interaction mechanisms in composite PCMs. Herein, to systematically understand the molecular motion mechanisms of PCMs with different functional groups (octadecane, octadecylamine, octadecanol and stearic acid) confined in the mesoporous MCM-41, we utilize molecular dynamics to simulate the spatial distribution and motion states of surface adsorbed PCMs molecules. This study aims to systematically reveal the interaction mechanisms between mesoporous MCM-41 and surface adsorbed PCMs at the molecular and atomic levels, thus providing constructive theoretical guidance and reference data for the targeted design and preparation of high-performance MCM-41-based composite PCMs. Image 1 • Molecular dynamics method is utilized to study thermal motion states of PCMs in mesoporous MCM-41. • The interaction mechanisms between MCM-41 and PCMs are systematically revealed at the molecular level. • It provides constructive guidance for the preparation of MCM-41-based composite PCMs. [ABSTRACT FROM AUTHOR]

Thermal energy storage at temperatures above 400 °C is critical for efficient industrial processes and continuous solar thermal power generation. Phase change materials (PCMs) can be used for both latent heat storage and improved conversion efficiencies, but their use has been prevented by the large, 5–25 % change in molar volume. Herein, shape-stabilized PCMs are prepared using 20% wt. mesoporous silica matrices and NaCl–NaBr–Na 2 MoO 4 salt eutectic. The pristine salt mixture has a total enthalpy of 216 Jg-1 divided into a solid-solid transition at 455 °C and solid – liquid transition at 522 °C. Six mesoporous silica materials of the MCM-41 (Mobil Composition of Matter No. 41), SBA-15 (Santa Barbara Amorphous) and mesocellular foam types were investigated as potential matrices for high temperature, shape-stabilized PCMs. All resulting composites have good thermal stability up to 650 °C. High – temperature optical microscopy shows that all samples retain their macroscopic solid shape above the salt melting point. Electron microscopy revealed a good dispersion of the silica matrix inside the molten salt phases. Both MCM-41 and SBA-15-type matrices yield PCMs with high total heat of fusion values between 169 – 178 Jg-1, in accordance to the 80% wt. salt fraction. The melting point is decreased with 5–10 °C for all composite materials, indicating nanoconfinement effects of the interparticle salt phase. This work therefore provides a new strategy for obtaining shape-stabilized materials useful for high – temperature heat storage. Image 1 • Shape-stabilized phase change materials obtained using mesoporous silica matrices. • 5%NaCl–40%NaBr–55%Na 2 MoO 4 (mol) eutectic as the high-temperature active phase. • All composites have high thermal stability (650 °C) at 80% wt. salt. • MCM-41 and SBA-15 best matrices for high heat storage (169–178 J/g). • With Declaration of interests. [ABSTRACT FROM AUTHOR]

Novel hollow mesoporous @M/CeO2 (M = Au, Pd, and Au–Pd) nanospheres are created. The nanospheres can be used as effective nanoreactors with superior catalytic activity and stability for reduction of 4-nitrophenol due to their hollow mesoporous structural features. [ABSTRACT FROM AUTHOR]

An MCM-41-immobilised bidentate nitrogen platinum complex (MCM-41-2N-Pt) was very conveniently synthesised from commercially available and cheap 3-(2-aminoethylamino)propyltrimethoxysilane by immobilisation on the mesoporous silica nanoparticles, MCM-41, followed by reaction with potassium chloroplatinite. It was found that the MCM-41-2N-Pt complex is a highly efficient catalyst for the hydrosilylation of olefins with triethoxysilane and can be easily recovered and reused several times without significant loss of activity. [ABSTRACT FROM AUTHOR]

• Hybrid membrane-adsorption system can achieve effective separation successfully. • A new configuration of hybrid membrane-adsorption process operated simultaneously. • MCM-41 adsorbent is a good helper for Methyl Green dye removal in hybrid system. • Simulated and actual wastewater removal is enhanced in integrated hybrid system. • Hybrid membrane-adsorption process demonstrates promise in industrial applications. In this work, three new configurations in a hybrid adsorption-membrane technique (HAMT) were adopted for the removal of methyl green dye (MG) from synthetic wastewater and tested the capability of HAMT on real sample from textile industry. The hybrid process involved the simultaneous activity of mesoporous material MCM-41 as an adsorbent, coupled with an ultrafiltration membrane (UF). The effects of the feed flow rate (100−200 ml/min), MG concentration (10−50 mg/l) and MCM-41 dose (0.008−0.06 g) were tested for each system configuration. The results proved the significant effect of the feed flow rate, feed concentration, and MCM-41 dose on both permeate flux and MG rejection. The rustles showed that the optimum configuration performance was in the following order: Batch filtration with the retentate full recycled > Semi-batch filtration > Single-pass continuous filtration. Where the highest permeate flux and rejection coefficient were 42.5 L/hr. m2 and 94.79 % for Batch filtration. This technique proved to be highly efficient in actual wastewater treatment by applying the resulted optimum conditions. Dye removal from actual sample more than 97 % and permeate flux equal 39 L/hr. m2 was achieved, proving that the HAMT is effective in removing dyes from synthetic and actual wastewater. [ABSTRACT FROM AUTHOR]

The anthropogenic cycle of Pd in the environment, its fate and impact is still unknown due to limitations of measurement techniques. For separation and pre-concentration of Pd(II) ions, mesoporous silica materials MCM-41 were synthesized and functionalized with different amounts of 3-mercaptopropyltrimethoxysilane (MPTMS) by co-condensation and grafting methods. The structural and textural properties of materials were characterized using XRD, TEM, SEM and BET techniques. The results proved that functionalization with thiol groups did not significantly affect structural and textural parameters of synthesized sorbents. The Pd(II) ions were quantitatively retained on sorbents functionalized by grafting in acidic solutions (pH 2), efficiently eluted with 0.1 mol L−1 thiourea solution in 1 mol L−1 HCl and determined by electrothermal atomic absorption spectrometry (ETAAS). The limit of detection (LOD) of the developed SPE ETAAS method was 0.06 ng mL−1, and the pre-concentration factor was 30. For analysis of Pd in environmental water samples inductively coupled plasma mass spectrometry (ICP-MS) in MS/MS mode was used. Spectral interferences on 105Pd caused by the presence of Sr in water samples were eliminated using helium (5 mL min−1) or ammonia (7 mL min−1) gas in collision/reaction cell. The developed SPE ICP-MS method is characterized by good selectivity in the presence of interfering elements and chloride ions and detection limit of 0.0002 ng mL−1. Its accuracy was confirmed by analysis of spiked water samples. The application of ICP-MS together with efficient separation/pre-concentration of analyte on thiol-functionalized MCM-41 sorbents allows to determine Pd in environmental water samples at pg mL−1 level. Image 1 • Thiol-functionalized MCM-41 materials were synthesized by co-condensation and grafting. • Materials were compared in terms of separation of trace amounts of Pd from waters. • Better sorption properties for Pd exhibited sorbent containing lower S content. • Sr interference on determination of 105Pd in seawater eliminated by helium collision cell. • New method suitable for analysis of Pd at pg/mL level in environmental waters developed. [ABSTRACT FROM AUTHOR]

The toxic and costly chemicals are usually used as the source of silicon for the synthesis of mesoporous materials. In this paper, the mesoporous material PS-MCM-41 was synthesized by hydrothermal synthesis, in which low-silicon content peanut shell ash is used as the silicon source. The properties of the obtained material were confirmed by N 2 physical adsorption, X-ray diffraction (XRD), SEM, TEM, and FTIR. The adsorption performance was evaluated during the adsorption experiment of crystal violet dye and compared with that of the mesoporous material MCM-41. The results showed that the peanut shell ash as silicon source could be used to successfully synthesize the mesoporous material PS-MCM-41. The adsorption efficiency of PS-MCM-41 to 50 mg/L crystal violet solution reached 99.90%, and the adsorption efficiency of PS-MCM-41 to 800 mg/L crystal violet solution reached 84.2%. Compared with MCM-41 and other adsorbents, PS-MCM-41 exhibited excellent adsorption properties and adsorption capacity for crystal violet. The adsorption kinetic data showed that the pseudo-secondary equation could better explain the adsorption data of the adsorption crystal violet. The adsorption isotherm model was consistent with the Langmuir model (R 2 > 0.99) with maximum adsorption capacities of 1428.57 mg/g. • PS-MCM-41 was synthesized using a low-silicon content peanut shell ash. • The adsorption properties of PS-MCM-41 on crystal violet was studied. • The adsorption kinetics of the material on crystal violet has been studied. • The adsorption isotherm mode of the material on crystal violet has been studied. [ABSTRACT FROM AUTHOR]

Two highly ordered isonicotinamide (INA)‐functionalized mesoporous MCM‐41 materials supporting indium and thallium (MCM‐41‐INA‐In and MCM‐41‐INA‐Tl) have been developed using a covalent grafting method. A surface functionalization method has been applied to prepare Cl‐modified mesoporous MCM‐41 material. Condensation of this Cl‐functionalized MCM‐41 with INA leads to the formation of MCM‐41‐INA. The reaction of MCM‐41‐INA with In(NO3)3 or Tl(NO3)3 leads to the formation of MCM‐41‐INA‐In and MCM‐41‐INA‐Tl catalysts. The resulting materials were characterized using various techniques. These MCM‐41‐INA‐In and MCM‐41‐INA‐Tl catalysts show excellent catalytic performance in the selective oxidation of sulfides and thiols to their corresponding sulfoxides and disulfides. Finally, it is found that the anchored indium and thallium do not leach out from the surface of the mesoporous catalysts during reaction and the catalysts can be reused for seven repeat reaction runs without considerable loss of catalytic performance. [ABSTRACT FROM AUTHOR]