Articles de revues : « Organosilicon Based Mesoporous Molecular Sieves »

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Luan, Zhaohua, Dongyuan Zhao, Heyong He, Jacek Klinowski et Larry Kevan. « Characterization of Aluminophosphate-Based Tubular Mesoporous Molecular Sieves ». Journal of Physical Chemistry B 102, n^o 7 (février 1998) : 1250–59. http://dx.doi.org/10.1021/jp973109a.

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Shi, Chunwei, Jingjing Liu, Wenyuan Wu, Xue Bian, Ping Chen, Zhanxu Yang et Chuantao Lu. « Toward Understanding of the Effect of Nucleation Temperature on Porous Structure of Micro-Mesoporous Composite Molecular Sieves and Related Crystallization Mechanism ». Catalysts 9, n^o 9 (17 septembre 2019) : 777. http://dx.doi.org/10.3390/catal9090777.

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Although micro-mesoporous composite molecular sieves have received significant attention due to their desirable properties, they still lack systematic studies on their crystallization process to achieve controllable synthesis of composite molecular sieves. In this study, a series of Y/SBA-15 micro-mesoporous composite molecular sieves with different porous structures were synthesized by tuning nucleation temperature, based on epitaxial growth on the outer surface of the Y-type crystal particle. All composite molecular sieves were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), and transmission electron microscope (TEM). Moreover, the effect of nucleation temperature on the structure of composite molecular sieves was investigated, while the crystallization mechanism was also explored. Furthermore, the performance of the molecular sieves on isomerization of n-pentane was investigated, the results suggested that the isomerization selectivity was positively correlated with regularity degree of the mesoporous porous structure, where the highest isomerization reached 95.81%. This work suggests that nucleation temperature plays a key role in structures of micro-mesoporous composite molecular sieves, providing a solid basis for the further development of functional composite molecular sieves.

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Zhao, X. S., et G. Q. (Max) Lu. « Aluminophosphate-based mesoporous molecular sieves : synthesis and characterization of TAPOs ». Microporous and Mesoporous Materials 44-45 (avril 2001) : 185–94. http://dx.doi.org/10.1016/s1387-1811(01)00183-4.

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Pertiwi, Yuvita Eka, et Maria Ulfa. « High Performance of Phenol Adsorption using Iron Based SBA-15 Synthesized by Loading-Microwave Method ». Oriental Journal of Chemistry 35, n^o 3 (20 juin 2019) : 1022–28. http://dx.doi.org/10.13005/ojc/350314.

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The iron based mesoporous silica (Fe2O3/SBA-15) was studied for the first time for adsorption of phenol as a model adsorbate compound. The structural and textural properties of the synthesized samples were characterized by means of X-Ray Diffraction, Transmission Electron Microscopy, FTIR and element analysis techniques by Energy Dispersive X-Ray (EDX). The result of XRD analysis showed that mesoporous SBA-15 silica molecular sieves which modified with Fe2O3has a hexagonal structure with a pore size is 4.90 nm and iron contents (25.27%) were found on the surface of the Fe2O3/mesoporous silica SBA-15. While the FTIR analysis showed that Fe2O3/SBA-15 had functional group of assymetric Si-O-Si and Fe-O-Si which was found at 1085 cm-1 and 678 cm-1, respectively. Adsorption performance of Fe2O3/SBA-15 material investigated by phenol compounds as adsorbate model. The optimum contact time is 60 minutes and the Kinetics model of the mesoporous SBA-15 silica molecular sieves modified Fe2O3 can adsorb phenol compounds following the Kinetics Model Ho and McKay. The result optimum adsorption capacity occuring in the adsorption of phenol compounds by of the mesoporous SBA-15 silica molecular sieves modified Fe2O3 is 114.000 mg/g.

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Pattnaik, Satyanarayan, et Kamla Pathak. « Mesoporous Silica Molecular Sieve based Nanocarriers : Transpiring Drug Dissolution Research ». Current Pharmaceutical Design 23, n^o 3 (20 février 2017) : 467–80. http://dx.doi.org/10.2174/1381612822666161026162005.

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Background: Improvement of oral bioavailability through enhancement of dissolution for poorly soluble drugs has been a very promising approach. Recently, mesoporous silica based molecular sieves have demonstrated excellent properties to enhance the dissolution velocity of poorly water-soluble drugs. Description: Current research in this area is focused on investigating the factors influencing the drug release from these carriers, the kinetics of drug release and manufacturing approaches to scale-up production for commercial manufacture. Conclusion: This comprehensive review provides an overview of different methods adopted for synthesis of mesoporous materials, influence of processing factors on properties of these materials and drug loading methods. The drug release kinetics from mesoporous silica systems, the manufacturability and stability of these formulations are reviewed. Finally, the safety and biocompatibility issues related to these silica based materials are discussed.

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Liu, Fengbao, Jinsheng Sun et Xiao Luo. « Preparation of MOF-Based Core-Shell Gel Particles with Catalytic Activity and Their Plugging Performance ». Gels 9, n^o 1 (4 janvier 2023) : 44. http://dx.doi.org/10.3390/gels9010044.

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Drilling fluid systems for deep and ultra-deep wells are hampered by both high-temperature downhole environments and lengthy cycle periods. Suppose that the gel particle-plugging agent, the primary treatment agent in the system, fails to offer durable and stable plugging performance. In such a scenario, the borehole wall is susceptible to instability and landslide after prolonged immersion, leading to downhole accidents. In this study, novel core-shell gel particles (modified ZIF) with ZIF particles employed as the core material and organosilicon-modified polyethylene polyamine (PEPA) as the polymer shell were fabricated using PEPA, in-house synthesized (3-aminopropyl) triethoxysilane (APTS), and the ZIF-8 metal-organic framework (MOF) as the raw materials to enhance the long-term plugging performance of gel plugging agents. The modified ZIF particles are nanoscale polygonal crystals and differ from conventional core-shell gel particles in that they feature high molecular sieve catalytic activity due to the presence of numerous interior micropores and mesopores. As a result, modified ZIF exhibits the performance characteristics of both rigid and flexible plugging agents and has an excellent catalytic cross-linking effect on the sulfonated phenolic resin (SMP-3) and sulfonated lignite resin (SPNH) in drilling fluids. Consequently, a cross-linking reaction occurs when SMP-3 and SPNH flow through the spacings in the plugging layer formed by the modified ZIF particles. This increases the viscosity of the liquid phase and simultaneously generates an insoluble gel, forming a particle-gel composite plugging structure with the modified ZIF and significantly enhancing the long-term plugging performance of the drilling fluid.

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Kuroda, Kazuyuki. « Silica-based mesoporous molecular sieves derived from a layered polysilicate kanemite?A review ». Journal of Porous Materials 3, n^o 2 (juin 1996) : 107–14. http://dx.doi.org/10.1007/bf01186040.

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Wu, Beina, Yaping Guo, Hongmei Cao, Yang Zhang, Lili Yu et Nengqin Jia. « A novel mesoporous molecular sieves-based electrochemilumenescence sensor for sensitive detection of azithromycin ». Sensors and Actuators B : Chemical 186 (septembre 2013) : 219–25. http://dx.doi.org/10.1016/j.snb.2013.05.080.

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Makshina, E. V., S. V. Sirotin, V. V. Yushchenko, G. N. Mazo, M. W. E. van den Berg, K. V. Klements’ev, W. Grünert et B. V. Romanovskii. « Nanocomposites based on LaCoO3 and mesoporous molecular sieves : Preparation and physicochemical and catalytic properties ». Kinetics and Catalysis 47, n^o 1 (janvier 2006) : 49–53. http://dx.doi.org/10.1134/s0023158406010083.

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Zhang, Han, et Haiyan Song. « Study of Adsorptive Denitrogenation of Diesel Fuel over Mesoporous Molecular Sieves Based on Breakthrough Curves ». Industrial & ; Engineering Chemistry Research 51, n^o 49 (3 décembre 2012) : 16059–65. http://dx.doi.org/10.1021/ie302169r.

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Prouzet, Eric, Frederic Cot, Georges Nabias, André Larbot, Patricia Kooyman et Thomas J. Pinnavaia. « Assembly of Mesoporous Silica Molecular Sieves Based on Nonionic Ethoxylated Sorbitan Esters as Structure Directors ». Chemistry of Materials 11, n^o 6 (juin 1999) : 1498–503. http://dx.doi.org/10.1021/cm9810281.

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Wu, Fan, Yang Liu, Hui Cheng, Yun Meng, Jieyun Shi, Yang Chen et Yelin Wu. « Enhanced Cancer Starvation Therapy Based on Glucose Oxidase/3-Methyladenine-Loaded Dendritic Mesoporous OrganoSilicon Nanoparticles ». Biomolecules 11, n^o 9 (14 septembre 2021) : 1363. http://dx.doi.org/10.3390/biom11091363.

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Cell autophagy is a well-known phenomenon in cancer, which limits the efficacy of cancer therapy, especially cancer starvation therapy. Glucose oxidase (GOx), which is considered as an attractive starvation reagent for cancer therapy, can effectively catalyze the conversion of glucose into gluconic acid and hydrogen peroxide (H2O2) in the presence of O2. However, tumor cells adapt to survive by inducing autophagy, limiting the therapy effect. Therefore, anti-cell adaptation via autophagy inhibition could be used as a troubleshooting method to enhance tumor starvation therapy. Herein, we introduce an anti-cell adaptation strategy based on dendritic mesoporous organosilica nanoparticles (DMONs) loaded with GOx and 3-methyladenine (3-MA) (an autophagy inhibition agent) to yield DMON@GOx/3-MA. This formulation can inhibit cell adaptative autophagy after starvation therapy. Our in vitro and in vivo results demonstrate that autophagy inhibition enhances the efficacy of starvation therapy, leading to tumor growth suppression. This anti-cell adaptation strategy will provide a new way to enhance the efficacy of starvation cancer therapy.

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Wang, Na, Jiao Wang, Jing Zhang, Chi Ma et Er Fan Chen. « Effect of MCM-41 and SBA-15 Mesoporous Molecular Sieves on Properties of PMMA-Based Composite ». Advanced Materials Research 391-392 (décembre 2011) : 274–77. http://dx.doi.org/10.4028/www.scientific.net/amr.391-392.274.

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Effects of different pore size nano-mesoporous molecular sieves fillers, i. e. MCM-41, SBA-15, together with organic-montmorillonite (OMMT), mixture of OMMT/MCM-41 or OMMT/SBA-15 (m (OMMT): m (MCM-41)/m (SBA-15) =1:1) and their amounts on mechanical properties of the polymethylmethacrylate (PMMA) composites were investigated. When the amount of OMMT/SBA-15 mixture was 0.5 %, tensile strength of the nano-composite reached maximum values of 46.3 MPa. When OMMT/SBA-15 mixture addition amount w (filler) was 1.2 %, impact strength of the nano-composite reached maximum values of 14 KJ/m2. In comparison with PMMA without any filler, the tensile strength and impact strength of nano-composite were increased by 8.4 % and 48 %, respectively.

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Jiang, T. S., X. P. Zhou, Y. H. Li, Q. Zhao et H. B. Yin. « Characterization of Zr-based MCM-41 mesoporous molecular sieves obtained by microwave irradiation or hydrothermal method ». Inorganic Materials 47, n^o 3 (mars 2011) : 296–302. http://dx.doi.org/10.1134/s0020168511030113.

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Salas, P., J. A. Wang, H. Armendariz, C. Angeles-Chavez et L. F. Chen. « Effect of the Si/Zr molar ratio on the synthesis of Zr-based mesoporous molecular sieves ». Materials Chemistry and Physics 114, n^o 1 (mars 2009) : 139–44. http://dx.doi.org/10.1016/j.matchemphys.2008.08.086.

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Feliczak, Agnieszka, Katarzyna Walczak, Agata Wawrzyńczak et Izabela Nowak. « The use of mesoporous molecular sieves containing niobium for the synthesis of vegetable oil-based products ». Catalysis Today 140, n^o 1-2 (février 2009) : 23–29. http://dx.doi.org/10.1016/j.cattod.2008.07.012.

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Zhang, Haoran, Bin Li, Bingfu Lei et Wenlian Li. « Oxygen-sensing materials based on [Ru(bpy)3]2+ covalently grafted MSU-3 mesoporous molecular sieves ». Journal of Luminescence 128, n^o 8 (août 2008) : 1331–38. http://dx.doi.org/10.1016/j.jlumin.2007.12.043.

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Wang, Yingying, Ge Wang, Mu Yang, Li Tan, Wenjun Dong et Rudy Luck. « Highly efficient olefin oxidation catalysts based on regular nano-particles of titanium-containing mesoporous molecular sieves ». Journal of Colloid and Interface Science 353, n^o 2 (janvier 2011) : 519–23. http://dx.doi.org/10.1016/j.jcis.2010.09.086.

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Shi, Chunwei, Xue Bian, Yongfu Wu, Yufeng Cong et Mingyuan Pei. « Catalytic Synthesis of n-Butyl Oleate by Cerium Complex Doped Y/SBA-15 Composite Molecular Sieve ». High Temperature Materials and Processes 37, n^o 2 (26 janvier 2018) : 107–11. http://dx.doi.org/10.1515/htmp-2016-0125.

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AbstractCerium ion was successfully incorporated into Y/SBA-15 micro-mesoporous molecular sieves via the hydrothermal synthesis method to give a series of composite materials. The prepared materials were thoroughly characterized using Fourier transform infrared spectroscopy (FT-IR), X-ray fluorescence spectroscopy (XRF), scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) and differential thermo gravimetric analysis (TG-DTG). The results showed that the prepared composite materials retained the highly ordered mesoporous two-dimensional hexagonal structure of SBA-15 and the octagonal structure of Y. The catalyst Ce-Y/SBA-15 was prepared and characterized, then the esterification of n-butanol and oleic acid was studied with bismuth phosphotungstate as a catalyst. Using this model reaction, the effects of Ce-HY/SBA-15, molar ratio of alcohol to oleic acid, amount of catalysts, reaction time and reaction temperature were investigated. The experimental results show that the optimal reaction conditions were: 1.8:1 molar ratio of alcohol to acid, 5 % catalyst amount (based on weight of oleic acid), 4 h reaction time and reflux conditions. Under these conditions, the yield of esterification was 90.6 %. The results suggest that the addition of Ce can effectively improve the catalytic properties of composite molecular sieves.

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Chen, L. F., X. L. Zhou, L. E. Noreña, J. A. Wang, J. Navarrete, P. Salas, A. Montoya, P. Del Angel et M. E. Llanos. « Comparative studies of Zr-based MCM-41 and MCM-48 mesoporous molecular sieves : Synthesis and physicochemical properties ». Applied Surface Science 253, n^o 5 (décembre 2006) : 2443–51. http://dx.doi.org/10.1016/j.apsusc.2006.04.064.

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Rathouský, Jiří, Markéta Zukalová, Arnošt Zukal et Jiří Had. « Homogeneous Precipitation of Siliceous MCM-41 and Bimodal Silica ». Collection of Czechoslovak Chemical Communications 63, n^o 11 (1998) : 1893–906. http://dx.doi.org/10.1135/cccc19981893.

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A new procedure for synthesis of MCM-41 siliceous molecular sieves with regular morphologies and bimodal mesoporous silica was developed. It is based on the precipitation from an isotropic reaction mixture. The decrease in pH, which causes the formation of solid particles, is achieved by the hydrolysis of ethyl acetate. The procedure is excellently reproducible and enables to obtain not only siliceous MCM-41 with the highest degree of pore ordering and phase purity but also a material of a new type, viz. bimodal silica containing both the MCM-41 mesopore system and the system of larger mesopores whose size ranges from 15 to 25 nm.

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Li, Ge, Baodong Wang, Qi Sun, Wayne Qiang Xu et Yifan Han. « Adsorption of lead ion on amino-functionalized fly-ash-based SBA-15 mesoporous molecular sieves prepared via two-step hydrothermal method ». Microporous and Mesoporous Materials 252 (novembre 2017) : 105–15. http://dx.doi.org/10.1016/j.micromeso.2017.06.004.

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Zhao, Hao, Zhaoping Zhong, Zhaoying Li et Wei Wang. « Research on catalytic pyrolysis of algae based on Py-GC/MS ». Royal Society Open Science 6, n^o 11 (novembre 2019) : 191307. http://dx.doi.org/10.1098/rsos.191307.

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In order to improve the quality of catalysis products of algae, composite molecular sieve catalyst was prepared by digestion and crystallization of HZSM-5 to reduce the oxygen content of the catalytic products. According to the analysis of the pyrolysis products, the best preparation conditions were chosen of tetra propylammonium hydroxide (TPAOH) solution 2.0 mol l −1 , cetyltrimethylammonium bromide (CTAB) solution 10 wt%, crystallization temperature 110°C, digestion–crystallization time: 24–24 h. The results indicate that the main function of catalysts is to promote the conversion of alcohols into hydrocarbons by reducing energy barriers. Catalysed by the composite molecular sieve, the content of alcohols in the pyrolysis products decreased from more than 30% to less than 10%, the content of hydrocarbons increased from 20% to nearly 60%, while all the adverse components remained at a low level, which indicates that the catalytic pyrolysis products are of high quality. The great deoxidation effect of composite molecular sieves is not only due to the expansion of the range of organic matter during re-pyrolysis, but also the increasing of the residence time of pyrolysis products inside the structure for the external mesoporous structure.

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Shao, Peijing, Han Chen, Qin Ying et Shihan Zhang. « Structure–Activity Relationship of Carbonic Anhydrase Enzyme Immobilized on Various Silica-Based Mesoporous Molecular Sieves for CO2 Absorption into a Potassium Carbonate Solution ». Energy & ; Fuels 34, n^o 2 (28 janvier 2020) : 2089–96. http://dx.doi.org/10.1021/acs.energyfuels.9b03860.

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Vlasenko, N. V., Yu N. Kochkin et A. S. Kovalenko. « Preparation of hybrid organo-inorganic catalysts based on MSM-41 mesoporous molecular sieves and their properties in synthesis of ethyl tert-butyl ether ». Russian Journal of Applied Chemistry 82, n^o 12 (décembre 2009) : 2166–73. http://dx.doi.org/10.1134/s1070427209120155.

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Balcar, Hynek, Naděžda Žilková, Martin Kubů, Michal Mazur, Zdeněk Bastl et Jiří Čejka. « Ru complexes of Hoveyda–Grubbs type immobilized on lamellar zeolites : activity in olefin metathesis reactions ». Beilstein Journal of Organic Chemistry 11 (4 novembre 2015) : 2087–96. http://dx.doi.org/10.3762/bjoc.11.225.

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Hoveyda–Grubbs type catalysts with cationic tags on NHC ligands were linker-free immobilized on the surface of lamellar zeolitic supports (MCM-22, MCM-56, MCM-36) and on mesoporous molecular sieves SBA-15. The activity of prepared hybrid catalysts was tested in olefin metathesis reactions: the activity in ring-closing metathesis of citronellene and N,N-diallyltrifluoroacetamide decreased in the order of support MCM-22 ≈ MCM-56 > SBA-15 > MCM-36; the hybrid catalyst based on SBA-15 was found the most active in self-metathesis of methyl oleate. All catalysts were reusable and exhibited low Ru leaching (<1% of Ru content). XPS analysis revealed that during immobilization ion exchange between Hoveyda–Grubbs type catalyst and zeolitic support occurred in the case of Cl− counter anion; in contrast, PF6 − counter anion underwent partial decomposition.

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Yarmo, Mohd Ambar, Raja Saadiah Raja Shariff, Siti Rohaya Omar, Juan Joon Ching et Roziana Haron. « New Perspective in Recent Solid Acid Catalyst ». Materials Science Forum 517 (juin 2006) : 117–22. http://dx.doi.org/10.4028/www.scientific.net/msf.517.117.

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This paper will review on the latest development on solid acid catalysts used in industries as well in research activities. Application of heterogeneous acid catalysis becomes current trend for many industries due to world wide environmental concern. Conventional synthetic or natural zeolites widely used for petrochemical processing, has some limitation because its pore size is normally smaller than reactant molecules. To overcome this challenge new delaminated zeolite process was introduced. In this process specific synthetic zeolite (i.e. ferrierite) was swelled up using specific surfactant followed by sonification to produce the delaminated zeolite. Further modification of this material such as sulfonification reaction to its surface has been found to improve the catalytic activity and selectivity for esterification reaction. Other acid catalyst systems based on mesoporous molecular sieves and Keggin heteropolyacids (HPA) are also discussed in this paper.

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Kruczala, Krzysztof. « (Invited) Oxygen Reduction Reaction in Alkaline Media : The Effect of Carbon Support Crystallinity, Conductivity, and Doping ». ECS Meeting Abstracts MA2022-01, n^o 49 (7 juillet 2022) : 2065. http://dx.doi.org/10.1149/ma2022-01492065mtgabs.

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The rapid development of energy consumption combined with growing environmental awareness is conducive to the wide-ranging search for ecological energy sources. In the recent decade, a significant amount of research has focused on the development of anion-exchange membrane (AEM) fuel cells (AEMFCs), as such approach exhibits faster oxygen reduction reaction (ORR) kinetics in the alkaline environment of the cell [1]. However, to become a serious alternative to the current mainstream acidic fuel cells, alkaline systems should overcome current limitations of performance and stability [2]. The design and synthesis of high-performance electrocatalysts facilitating the slow oxygen reduction reaction (ORR) is, therefore, a key issue in the context of the full commercialization of fuel cells. Transition metal oxides with spinel structure constitute an interesting group of potential catalysts that can replace the widely used materials based on Pt [3, 4]. However, due to the low electrical conductivity and the tendency to undesirable aggregation of spinel nanoparticles, it is important to support them on appropriate carbon carriers. Since the nature of the carbon carrier plays a significant role in the ORR activity, we aimed to comprehensively investigate the influence of the electric conductivity of carbon supports, the role of the surface functional oxygen-bearing groups, and doping with heteroatoms on the performance of the bare and cobalt-manganese spinels deposited on the functionalized carbon supports, acting as ORR electrocatalysts in the alkaline media [5]. We investigated commercially available Vulcan XC-72, Printex85, MWCNT, amorphous carbon (C-am.), and carbons synthesized by structural nano-replication using the mesoporous molecular sieves MCM-48 (carbon denoted CMK-1) and the spherical silica calcinated at temperature range 650-1050 oC (SPH-650-1050). To investigate the effect of doping on the ORR catalytical activity the MWCNT was modified by nitrogen and sulfur heteroatoms. Additionally, the doped supports were then treated by plasma to introduce surface oxygen groups. On all investigated carbon supports the nanoparticles of manganese-cobalt spinel were dispersed. They were prepared at 150oC by a microwave-assisted hydrothermal route. Comprehensive physicochemical characterization of carbon support was performed using Raman and UV-Vis spectroscopies, XPS, TPD, XRD, TGA techniques, electron microscopy (TEM), and N2 adsorption (BET) (Figure 1). The relative electric conductivity measurements were performed using the contactless microwave technique. The electrochemical properties of the obtained materials were determined by cyclic voltammetry (CV), whereas the electrocatalytic activity of the obtained materials towards ORR was determined using the RDE and RRDE techniques. It was found that the nature of the carbon carrier plays a triple role in the ORR activity, determining dispersion and faceting of the spinel nanoparticles, as well as the extent of the undesired 2e– reduction pathway, controlled by the fraction of an amorphous component. In the case of SPH samples, it was shown that with the increasing carbonization temperature of the carbon support the electric conductivity increase in parallel to the crystallization extent. The electrocatalytic performance of the carbon carriers and the supported cobalt manganese spinels exhibits a volcano-type shape reaching the maximum for carbon materials obtained at 850°C. Such dependence results from two descriptors changing oppositely with the carbonization temperature: an increasing electric conductivity and a decreasing amount of the carbonyl and quinone groups in the sample. The electric conductivity multiplied by the amount of the carboxyl and quinone groups exhibits the same variation with the carbon calcination temperature as the number of electrons exchanged in ORR, confirming that optimal conjunction of these both properties plays a decisive role in this process. The dispersed spinel active phase favors the direct 4e− pathway of ORR and improves the value of the E onset potential distinctly. To the best of our knowledge, the role of electric conductivity and surface oxygen functionalities in the ORR activity over carbon materials and supported spinel electrocatalysts was disentangled for the first time in this study. Acknowledgments: This work was supported by the Polish National Science Centre (NCN) project OPUS-14, No. 2017/27/B/ST5/01004. References: D.R. Dekel; J. Power Sources, 2018, 375, 158–169. https://doi.org/10.1016/j.jpowsour.2017.07.117. S. Wierzbicki, J.C. Douglin, A. Kostuch, D.R. Dekel, K. Kruczała; J. Phys. Chem. Lett., 2020, 11, 7630−7636. https://doi.org/10.1021/acs.jpclett.0c02349 A. Kostuch, J. Gryboś, P. Indyka, L. Osmieri, S. Specchia, Z. Sojka, K. Kruczała; Catal. Sci. Technol., 2018, 8, 642-655. https://doi.org/10.1039/c7cy02228j A. Kostuch, J. Gryboś, S. Wierzbicki, Z. Sojka and K. Kruczała, Materials, 2021, 14, 820. https://doi.org/10.3390/ma14040820 A. Kostuch, S. Jarczewski, M.K. Surówka, P. Kuśtrowski, Z. Sojka, K. Kruczała; Catal. Sci. Technol., 2021,11, 7578-7591 https://doi.org/10.1039/d1cy01115d Figure 1

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Lei, Jinhua, Zhongzheng Li, Tian He, Zhuqian Wang, Shitao Yao et Huayu Qiu. « Lubricant controlled release silicone fouling release coatings based on mesoporous molecular sieves ». Journal of Coatings Technology and Research, 16 décembre 2022. http://dx.doi.org/10.1007/s11998-022-00702-1.

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Reddy, Kondam Madhusudan, et Chunshan Song. « Synthesis and Catalytic Applications of Novel Mesoporous Aluminosilicate Molecular Sieves ». MRS Proceedings 454 (1996). http://dx.doi.org/10.1557/proc-454-125.

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ABSTRACTThis paper reports on the synthesis of four series of mesoporous aluminosilicate molecular sieves (Al-MCM-41) and their catalytic applications. Four different aluminum compounds were examined as Al source in the hydrothermal synthesis of the mesoporous aluminosilicates of MCM-41 type, including pseudo boehmite (alumina), aluminum sulfate, aluminum isopropoxide, and sodium aluminate. Each Al source was examined at three different feed Si/Al ratios in the synthesis. XRD results show that there are differences in the dioo-spacings for the samples prepared with different Al sources: sodium aluminate > Al isopropoxide > Al sulfate > pseudo boehmite. Such differences reveal that Al incorporation in the framework increases in the following order: pseudo boehmite < Al sulfate < Al isopropoxide < sodium aluminate. XRD also indicates that the synthesized Al-MCM-41 samples have different crystallinity. 27Al NMR and 29Si NMR reveal that most of the Al species in the samples prepared with pseudo boehmite were present in octahedral coordination, whereas in other samples nearly all the Al species are tetrahedral (in the framework). The acid characteristics of the synthesized molecular sieves were characterized by temperature-programmed desorption of n-butylamine, and by using 1,3,5-triisopropylbenzene hydrocracking as probe reaction. The results of TPD and probe reaction clearly indicate that the Al source used for synthesis has a major impact on the acidic and catalytic properties of Al-MCM-41. The samples prepared with Al isopropoxide and sodium aluminate are better as catalysts than those with Al sulfate and pseudo boehmite. We also explored the potential of mesoporous molecular sieves as support for noble metal hydrogenation catalysts and metal sulfide-based hydrotreating catalysts. Pd and Pt-loaded mesoporous molecular sieves were prepared and applied for hydrogenation of naphthalene and phenanthrene. The results show that mesoporous molecular sieve-supported catalysts are much more active than alumina- and titania-supported catalysts. The data for dibenzothiophene hydrodesulfurization suggest that Al-MCM-41 supported Co-Mo may be effective for deep desulfurization of distillate fuels.

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Ma, Wenqing, Yuanrong Yi, Minghang Fang, Chunhui Li, Jie Li et Wei Liu. « Study on the synthesis mechanism of sodalite, gismondine, and zeolite-P1 zeolite materials from ladle furnace slag and fly ash ». Scientific Reports 13, n^o 1 (24 février 2023). http://dx.doi.org/10.1038/s41598-023-30282-y.

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AbstractIn this study, geopolymers were prepared using ladle furnace slag (LFS) and fly ash (FA), and hydrothermal treatment was then used to synthesize bulk zeolite molecular sieves with gismondine, zeolite-P1, and sodalite phases. The effect of the synthesis conditions on the crystalline phases of the zeolite molecular sieves was investigated by XRD. The results showed that the best zeolite molecular sieves were prepared with an LFS: FA ratio of 4: 6, a curing temperature of 40 °C, a curing time of 12 h, a sodium silicate modulus (Ms) of 1.4, a NaOH concentration of 4 mol/L, a hydrothermal temperature of 120 °C, and a hydrothermal time of 12 h. On this basis, the products were analyzed by SEM, N2 adsorption, and FT-IR. The results showed that the synthesized zeolite molecular sieves had mesoporous properties, and the degree of polymerization and cross-linking of the silica-aluminate gel were enhanced after hydrothermal treatment. In addition, the formation mechanism of the zeolite molecular sieves was explored through the changes of the silica-alumina during zeolite formation. This paper is the first to use the hydrothermal conversion of zeolite molecular sieves from LFS-FA based polymers to provide some guidance for the resource utilization of LFS and FA.

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Pinnavaia, Thomas J., Peter T. Tanev, Jialiang Wang et Wenzhong Zhang. « Ti - Substituted Mesoporous Molecular Sieves for Catalytic Oxidation of Large Aromatic Compounds Prepared by Neutral Templating Route ». MRS Proceedings 371 (1994). http://dx.doi.org/10.1557/proc-371-53.

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AbstractA new synthesis route to open framework mesostructures based on H-bonding and self-assembly between neutral primary amine surfactants (S°) and neutral inorganic precursors (I°) has been used to prepare hexagonal mesoporous silicas containing site isolated titanium centers. These new titanosilicates, designated Ti-HMS, exhibit exceptional catalytic reactivity for the oxidation of substrates too large to access the pore structure of conventional titanosilicates, such as titanium silicalite, TS-1. The catalytic properties of Ti-HMS materials for the peroxide oxidation of 2,6- di- tert-butylphenol are compared with those of microporous TS-1 and a mesoporous Ti-MCM-41 analog prepared by an electrostatic templating mechanism using a liquid crystal quaternary ammonium cationic surfactant.

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Gimon-Kinsel, Mary E., Trinidad Muñoz et Kenneth J. Balkus. « Pulsed Laser Ablation of Low-Density Nanoporous Metal Oxides ». MRS Proceedings 526 (1998). http://dx.doi.org/10.1557/proc-526-391.

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AbstractPulsed laser ablation has been employed to generate thin films of low density metal oxides, including nanoporous molecular sieves. An excimer laser (KrF*, 248 nm) was used to deposit molecular sieve films onto a variety of substrates including polished silicon, platinum, tantalum, titanium nitride, glass, indium-doped tin oxide, copper and Mylar. Recent results for the deposition of microporous UTD-1 and FeAPO-5 as well as mesoporous aluminosilicate MCM-41 and Nb-TMSI molecular sieve films are presented. The order (crystallinity) of the laser deposited films has been shown to be enhanced by a brief post hydrothermal treatment. A vapor phase treatment of the laser deposited FeAPO-5 films allows for increases in film crystallinity without an increase in film thickness. Hydrothermal treatment of laser deposited Nb-TMSI results in “worm hole” pore motif which is new for this composition. Silicate based molecular sieves such as UTD-1 and aluminosilicate MCM-41 require a UV-absorbing guest molecule for laser ablation giving rise to a phenomenon referred to as guest assisted laser ablation (GALA). The molecular sieve films were characterized by x-ray diffraction, scanning electron microscopy and transmission electron microscopy.

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Xu, Fan, Yuke Li, Qing Zou, Yu Shuang He, Zijia Shen, Chen Li, Huijuan Zhang, Feipeng Wang, Jian Li et Yu Wang. « The electric field cavity array effect of 2D nano-sieves ». Nature Communications 13, n^o 1 (22 décembre 2022). http://dx.doi.org/10.1038/s41467-022-35623-5.

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AbstractFor the upsurge of high breakdown strength ($${{{{{{\rm{E}}}}}}}_{{{{{{\rm{b}}}}}}}$$ E b ), efficiency ($${{{{{\rm{\eta }}}}}}$$ η ), and discharge energy density ($${{{{{{\rm{U}}}}}}}_{{{{{{\rm{e}}}}}}}$$ U e ) of next-generation dielectrics, nanocomposites are the most promising candidates. However, the skillful regulation and application of nano-dielectrics have not been realized so far, because the mechanism of enhanced properties is still not explicitly apprehended. Here, we show that the electric field cavity array in the outer interface of nanosieve-substrate could modulate the potential distribution array and promote the flow of free charges to the hole, which works together with the intrinsic defect traps of active Co3O4 surface to trap and absorb high-energy carriers. The electric field and potential array could be regulated by the size and distribution of mesoporous in 2-dimensional nano-sieves. The poly(vinylidene fluoride-co-hexafluoropropylene)-based nanocomposites film exhibits an $${{{{{{\rm{E}}}}}}}_{{{{{{\rm{b}}}}}}}$$ E b of 803 MV m−1 with up to 80% enhancement, accompanied by high $${{{{{{\rm{U}}}}}}}_{{{{{{\rm{e}}}}}}}$$ U e = 41.6 J cm−3 and $${{{{{\rm{\eta }}}}}}\,$$ η ≈ 90%, outperforming the state-of-art nano-dielectrics. These findings enable deeper construction of nano-dielectrics and provide a different way to illustrate the intricate modification mechanism from macro to micro.

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Su, J., M. Gherasimova, G. Cui, J. Han, S. Lim, D. Ciuparu, L. Pfefferle et al. « Vapor-liquid-solid Growth of III-Nitride Nanowires and Heterostructures by Metal-Organic Chemical Vapor Deposition ». MRS Proceedings 831 (2004). http://dx.doi.org/10.1557/proc-831-e12.4.

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ABSTRACTWe report flexible synthesis of III-Nitride nanowires and heterostructures by metal-organic chemical vapor deposition (MOCVD) via a catalytic vapor-liquid-solid (VLS) growth mechanism. Indium is used as an in-situ catalyst to facilitate and sustain the stability of liquid phase droplet for VLS growth based on thermodynamic consideration. The employment of mesoporous molecular sieves (MCM-41) helps to prevent the coalescence of catalyst droplets and to promote nucleation statistics. Cathodoluminescence (CL) of GaN nanowires shows near band-edge emission at 370nm, and strong E2 phonon peak is observed at room temperature in Raman scattering spectra. Both binary GaN and AlN nanowires have been synthesized by MOCVD. Three-dimensional AlN/GaN trunk-branch nanostructures are reported to illustrate the versatility of incorporating the VLS mechanism into MOCVD process.

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