Ordered mesoporous material

Keywords extra-large pore materials, ordered mesoporous materials,... 

In the family of copolymer-templated materials, ordered mesoporous silicas consisting of interconnected large cage-like pores are also of significant interest. 

Silica a Sol-Gel Derived Material, Ordered Mesoporous Silica, Hybrids... 

Mesostructured inorganic solids, originated from self-assembling of supramolec-ular structures, represent a class of suitable templates for the achievement of nanostructured materials. Ordered mesoporous polymers and carbonaceous frameworks... 

Z. Peng/Joumal of Materials Ordered mesoporous carbon-CNT -46 1.2 80 BM CDI 0.63... 

Sulfonic Acid Functionalization of Ordered Mesoporous Materials and Periodic Organosilicas... 

Liu, J Kim, AY Virden, JW Bunker, BC, Effect of Colloidal Particles on the Eormation of Ordered Mesoporous Materials, Langmuir 11, 682, 1995. 

It should be mentioned that the structure of carbon supports could have significant influence on the electro-catalytic properties of the nanocomposite catalysts. Recently, Pt/Ru nanoclusters prepared by the alkaline EG method were impregnated into a synthesized carbon support with highly ordered mesoporous. Although the Pt/ Ru nanoclusters can be well dispersed in the pores of this carbon substrate, the long and narrow channels in this material seem not suitable for the application in... 

By using other templates, the size of metal nanoparticles can be also controlled. Chen et al. reported the sonochemical reduction of Au(III), Ag(I) and Pd(II) and synthesis of Au, Ag and Pd nanoparticles loaded within mesoporous silica [48,49]. Zhu et al. also reported the sonochemical reduction of Mn04 to Mn02 and synthesis of Mn02 nanoparticles inside the pore channels of ordered mesoporous cabon [50]. Taking into account these reports, the rigid pore of inorganic materials can be used as a template for the size controlled metal nanoparticle synthesis even in the presence of ultrasound. 

Liu, R., Ren, Y., Shi, Y., Zhang, F., Zhang, L., Tu, B., and Zhao, D. (2007) Controlled synthesis of ordered mesoporous C—Ti02 nanocomposites with crystalline titania frameworks from organic-inorganic-amphiphilic coassembly. Chemistry of Materials, 20 (3), 1140-1146. 

Yiu, H.H.P. and Wright P.A. (2005) Enzymes supported on ordered mesoporous solids a special case of an inorganic-organic hybrid. Journal of Materials Chemistry, 15, 3690-3700. 

Incorporation of nitrogen into the carbons prepared via chemical vapour deposition (CVD) or into the carbon nanotubes yields highly graphitised materials with excellent structure ordering. For example, ordered mesoporous carbons containing 7.0-8.8 wt,% N have been obtained by the CVD method, using the SBA-12, SBA-15, MCM-41, MCM-48, and HMS materials as matrices and acetonitrile as carbon precursor [1],... 

Invented less than a decade ago,1 EISA has rapidly developed into a universal technique for fabrication of organized porous and patterned nanocomposite materials, ranging from metal oxides and chalcogenides to carbons, polymers, and metals.2,3 In addition to generating ordered mesoporous films, this technique may also be used to incorporate functional molecules and... 

Although the mesoporous materials, such as Ti-MCM-41, have lower intrinsic epoxidation selectivity than TS-1 and Ti-beta, they must nevertheless be used as catalysts for reactions of large molecules typical in the fine chemicals industry. It is, therefore, interesting to elucidate how these ordered mesoporous materials compare with the earlier generation of amorphous titania-silica catalysts. Guidotti et al (189) recently compared Ti-MCM-41 with a series of amorphous titania-silica catalysts for the epoxidation of six terpene molecules of interest in the perfumery industry (Scheme 6). Anhydrous TBHP was used as the oxidant because the catalytic materials are unstable in water. The physical characteristics of these catalysts are compared in Table XII. 

We also include in this class of quasi-2D nanostructured materials Titania deposited inside ordered mesoporous silica (because an inner coating of mesoporous silica may be realized), or nano-dot type Titania particles well dispersed in the ordered porous matrix. We do not consider here solids which contain linear or zig-zag type TiOTiO-nanowires in a microcrystalline porous framework, such as ETS-4 and ETS-10, notwithstanding the interest of these materials also as photocatalysts,146-151 because these nanowires are located inside the host matrix, and not fully accessible from the gas reactants (the reactivity is essentially at pore mouth). 

The most widely studied member of the M41S family is hexagonal MCM-41, which was first prepared by the I S+ liquid-crystal approach (168, 169). A charged surfactant like CTAB produces well-ordered mesoporous materials having ID... 

Surface Modifications of Ordered Mesoporous Silica Materials. .122... 

Ordered mesoporous materials of compositions other than silica or silica-alumina are also accessible. Employing the micelle templating route, several oxidic mesostructures have been made. Unfortunately, the pores of many such materials collapse upon template removal by calcination. The oxides in the pore walls are often not very well condensed or suffer from reciystallization of the oxides. In some cases, even changes of the oxidation state of the metals may play a role. Stabilization of the pore walls in post-synthesis results in a material that is rather stable toward calcination. By post-synthetic treatment with phosphoric acid, stable alumina, titania, and zirconia mesophases were obtained (see [27] and references therein). The phosphoric acid results in further condensation of the pore walls and the materials can be calcined with preservation of the pore system. Not only mesoporous oxidic materials but also phosphates, sulfides, and selenides can be obtained by surfactant templating. These materials have pore systems similar to OMS materials. 

Ordered mesoporous materials, such as described here, have been successfully tested as catalysts or catalyst supports for many different reactions [27], However, since this class of materials is rather new, the real potential of these materials in catalysis is of course not fully investigated. As for OMS materials, the production of such materials is rather cost intensive, e.g., compared to conventional oxide materials. Therefore, the benefit of a regular mesopore system has to be substantial to justify the use of elaborated but expensive catalyst materials for industrial applications. Nevertheless, many of the materials described above proved to perform very well in many different catalytic reactions and they may of course find applications in this field. 

High-surface-area inorganic materials with ordered mesoporous structures have also been oT major interest Tor numerous applications including photocatalysis [99-102], The ultra-high-surface-area of mesoporous materials is appealing in applications of heterogeneous photocatalysis where it is desirable to minimize the distance between the site of photon absorption and electron-hole redox reactions to improve efficiency [103-105],... 

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