Ordered Mesoporous Materials

Ordered Mesoporous Materials
Author: Dongyuan Zhao
Publisher: John Wiley & Sons
Total Pages: 544
Release: 2012-11-28
Genre: Science
ISBN: 3527647899

Mesoporous materials are a class of molecules with a large and uniform pore size, highly regular nanopores, and a large surface area. This book is devoted to all aspects and types of these materials and describes, in an in-depth and systematic manner, the step-by-step synthesis and its mechanism, as well as the characterization, morphology control, hybridization, and applications, of mesoporous molecular sieves. In so doing, it covers silicates, metal-doped silicates, nonsilicates, and organic-inorganic hybrids. Although the emphasis is on synthesis, the expert authors also discuss characterization and applications, ranging from catalysis and biochemistry to optics and the use of these materials as templates for nanomaterial synthesis. Both the fundamentals and the latest research results are covered, ensuring that this monograph serves as a reference for researchers in and newcomers to the field.

Synthesis and Characterization of Ordered Mesoporous Inorganic Nanocomposite Materials

Synthesis and Characterization of Ordered Mesoporous Inorganic Nanocomposite Materials
Author: Pasquale Fernando Fulvio
Publisher:
Total Pages: 210
Release: 2009
Genre: Mesoporous materials
ISBN:

Ordered mesoporous inorganic nanocomposite materials were synthesized by using soft- and hard-templating strategies. Ordered mesoporous silicas (OMSs) were obtained by soft templating, whereas ordered mesoporous carbons (OMCs) and mesoporous mixed metal oxides were prepared by hard templating. Also, post-synthesis modification of OMSs was carried out by deposition of mixed metal oxides, carbon and nickel. The resulting materials were characterized by nitrogen and argon adsorption, thermogravimetric analysis, small angle X-ray scattering, powder X-ray diffraction, scanning and transmission electronic microscopy, elemental analysis, temperature programmed desorption and diffuse reflectance Fourier transform infrared spectroscopy. The first part of this dissertation is devoted to the optimization of experimental conditions such as time, temperature, pH and salt addition for the synthesis of several OMSs: SBA-15, SBA-16 and FDU-1. The size of ordered mesopores, surface area and pore volume of the aforementioned OMSs were tailored by adjusting the synthesis time and temperature as well as by combining solvent extraction and calcination for the template removal. A further improvement of SBA-16 and FDU-1 was achieved by using low acid concentration and adding NaCl addition, which resulted in OMSs with large cage diameters and uniform pore openings. Subsequently, the SBA-15 and SBA-16 materials were employed as hard templates for the synthesis of OMCs, using iron chloride as a catalyst for in situ polymerization of pyrrole. After carbonization and silica dissolution, the nitrogen-doped OMCs with tunable mesopores, graphitic domains and magnetic iron-iron carbide nanoparticles were obtained. Also, the pore walls of SBA-15 were modified with 2, 3-dihydroxy naphthalene, which was converted into thin carbon film. The impregnation of the resulting SBA-15-carbon nanocomposites with nickel salts afforded materials with "pea-pod" distribution of nickel nanoparticles. In addition, the pore walls of SBA-15 were modified with metal alkoxides of Al, Ti, and Zr by using a partially hydrolytic sol-gel process, which depending on the experimental conditions resulted in the deposition of thin films and nanoparticles of these oxides. Finally, OMCs were used as hard templates for the synthesis of mesoporous iron-doped alumina-titania mixed oxides, which exhibited high Lewis acidity and partially retained the structural symmetry of the templates used.

Combined and Hybrid Adsorbents

Combined and Hybrid Adsorbents
Author: José M. Loureiro
Publisher: Springer Science & Business Media
Total Pages: 372
Release: 2006-10-03
Genre: Nature
ISBN: 1402051700

This book follows up an Advanced Research Workshop dedicated to the subject of adsorption. It presents an up-to-date review of the latest achievements in the synthesis, characterization and applications of hybrid organic-inorganic materials and of carbon and combined adsorbents. The modeling of the adsorption process, including the simulation of carbon masks used for both civil and military protection purposes is also addressed. Includes applications in environmental, military and post-disaster situations.

Synthesis, Characterization and Physicochemical Properties of Platinum Naboparticles on Ordered Mesoporous Carbon

Synthesis, Characterization and Physicochemical Properties of Platinum Naboparticles on Ordered Mesoporous Carbon
Author: Waheed Saban
Publisher:
Total Pages: 190
Release: 2011
Genre: Electrocatalysts
ISBN:

In this study SBA-15 mesoporous silica template was synthesized and used as a sacrificial template in the preparation of ordered mesoporous carbon material. A chemical vapour deposition (CVD) technique using LPG or alternatively sucrose, pyrolyzed upon a mesoporous Si matrix were used to produce nanostructured ordered mesoporous carbon (OMC) with graphitic character after removing the Si template. The sucrose method was found to be a suitable route for preparing OMC. The OMC was used as a conductive three dimensional porous support for depositing catalytic nanophase Pt metal. Deposition of Pt nanoparticles on OMC was accomplished using a CVD method with Pt(acac)2 as a precursor. The synthesized nano-composite materials were characterized by several techniques such as, HRTEM, HRSEM, EDS, XRD, BET, TGA, FT-IR and CV.

Synthesis, Characterization, and Application of Surface-functionalized Ordered Mesoporous Nanoparticles

Synthesis, Characterization, and Application of Surface-functionalized Ordered Mesoporous Nanoparticles
Author:
Publisher:
Total Pages: 127
Release: 2009
Genre:
ISBN:

The dissertation begins with Chapter 1, which is a general introduction of the fundamental synthesis of mesoporous silica materials, the selective functionlization of mesoporous silica materials, and the synthesis of nanostructured porous materials via nanocasting. In Chapter 2, the thermo-responsive polymer coated mesoporous silica nanoparticles (MSN) was synthesized via surface-initated polymerization and exhibited unique partition activities in a biphasic solution with the thermally induced change. In Chapter 3, the monodispersed spherical MSN with different mesoporous structure (MCM-48) was developed and employed as a template for the synthesis of mesoporous carbon nanoparticles (MCN) via nanocasting. MCN was demonstrated for the delivery of membrane impermeable chemical agents inside the cells. The cellular uptake efficiency and biocompabtibility of MCN with human cervical cancer cells were also investigated. In addition to the biocompabtibility of MCN, MCN was demonstrated to support Rh-Mn nanoparticles for catalytic reaction in Chapter 4. Owing to the unique mesoporosity, Rh-Mn nanoparticles can be well distributed inside the mesoporous structure and exhibited interesting catalytic performance on CO hydrogenation. In Chapter 5, the synthesis route of the aforementioned MCM-48 MSN was discussed and investigated in details and other metal oxide nanoparticles were also developed via nanocasting by using MCM-48 MSN as a template. At last, there is a general conclusion summarized in Chapter 6.

Nanocasting

Nanocasting
Author: An-Hui Lu
Publisher: Royal Society of Chemistry
Total Pages: 279
Release: 2010
Genre: Science
ISBN: 0854041885

Nanostructured materials with tailored properties are regarded as a fundamental element in the development of future science and technology. Research is still ongoing into the nanosized construction elements required to create functional solids. The recently developed technique, nanocasting, has great advantage over others in terms of the synthesis of special nanostructured materials by the careful choice of suitable elements and nanoengineering steps. This new book summarizes the recent developments in nanocasting, including the principles of nanocasting, syntheses of novel nanostructured materials, characterization methods, detailed synthetic recipes and further possible development in this area. The book focuses on the synthesis of porous solids from the viewpoint of methodology and introduces the science of nanocasting from fundamental principles to their use in synthesis of various materials. It starts by outlining the principles of nanocasting, requirements to the templates and precursors and the tools needed to probe matter at the nanoscale level. It describes how to synthesize nano structured porous solids with defined characteristics and finally discusses the functionalization and application of porous solids. Special attention is given to new developments in this field and future perspectives. A useful appendix covering the detailed synthetic recipes of various templates including porous silica, porous carbon and colloidal spheres is included which will be invaluable to researchers wanting to follow and reproduce nanocast materials. Topics covered in the book include: * inorganic chemistry * organic chemistry * solution chemistry * sol-gel and interface science * acid-base equilibria * electrochemistry * biochemistry * confined synthesis The book gives readers not only an overview of nanocasting technology, but also sufficient information and knowledge for those wanting to prepare various nanostructured materials without needing to search the available literature.

Synthesis, Adsorption and Structural Properties of Carbons with Uniform and Ordered Mesopores

Synthesis, Adsorption and Structural Properties of Carbons with Uniform and Ordered Mesopores
Author: Kamil Gierszal
Publisher:
Total Pages: 194
Release: 2008
Genre: Carbon
ISBN:

Various novel carbon mesostructures were explored with respect to their synthesis methods, adsorption properties as well as structural properties. Several important problems were studied including the structural ordering of ordered mesoporous carbons (OMCs), selection of carbon precursors, controlling the pore size, specific surface area and total pore volume of the resulting carbons. Ordered mesoporous silicas (OMSs) and silica colloidal templates were employed as hard templates. The obtained results have been divided into two major chapters dealing with: OMCs synthesized by using OMSs as templates and the mesoporous carbons templated by silica colloidal materials. The first aforementioned chapter presents the following problems. Two different OMSs, SBA-15 and KIT-6, were employed as hard templates and various carbon precursors including mesophase pitches of different softening points were used for the purpose to investigate the relation between the structure of OMCs and their adsorption properties. One of the most important conclusions was that the softening temperature of mesophase pitch clearly affected the structural properties of the resulting OMCs through the formation of different amount of micropores. The other studies involved the synthesis and characterization of OMCs templated by the SBA-16 silica with precisely controlled pore sizes. For this purpose, various carbon precursors were used - sucrose, acenaphthene and furfuryl alcohol. Two types of OMCs were prepared - the fully-filled inverse carbon replicas and the film-type inverse replicas of the SBA-16 silica. The second chapter deals with mesoporous carbons templated by silica colloidal crystals (SCCs) and disordered colloidal silicas. These templates served for the synthesis of mesoporous carbons from mesophase pitch as carbon precursors. The SCC was formed by evaporation method using the aqueous suspension of 46 nm uniform silica colloids, whereas the same method applied to 16 and 31 nm silica nanoparticles afforded only disordered aggregates. Application of these templates showed for the first time that it is possible to achieve the faithful inverse carbon replica of the well-ordered SCC composed of such small colloids. The other problem was devoted to graphitization of SCC-templated OMC. Here, well-graphitizable mesophase pitch as carbon source and SCC formed from 70 nm nanoparticles were employed. Carbonization at 1000 °C and subsequent graphitization of OMC at temperature as high as 2500 °C allowed one to obtain an excellent quality porous carbon ordered at nanoscale and at molecular level. The most important achievement reported in this dissertation was the synthesis of mesoporous carbons with extremely large pore volume and narrow pore size distribution. The structure was synthesized with the use of colloidal silica and resorcinol-crotonaldehyde as template and carbon precursor, respectively. The large pore volume could be obtained by formation of uniform thin carbon film on the pore walls of the aggregates of silica nanoparticles. Such prepared carbons with uniform mesopores reached the highest ever reported value of the total pore volume of 9̃ cm3/g. Also, new mathematical relations between basic adsorption parameters were derived. Various measuring techniques were used in order to characterize the adsorption and structural properties of the studied nanoporous materials. Among them were nitrogen adsorption, elemental analysis, powder X-ray diffraction (XRD), small angle X-ray scattering (SAXS), transmission and scanning electron microscopy (TEM/SEM), thermogravimetric analysis (TGA), Raman spectroscopy.

Synthesis and Characterization of CMK Porous Carbons Modified with Metals Applied to Hydrogen Uptake and Storage

Synthesis and Characterization of CMK Porous Carbons Modified with Metals Applied to Hydrogen Uptake and Storage
Author: Marcos B. Gómez
Publisher:
Total Pages:
Release: 2016
Genre: Science
ISBN:

In this chapter, we have shown that hopeful hydrogen storage material can be obtained by ordered mesoporous carbons (carbons mesostructured from Korea, CMK-1 and CMK-3) and modified with metal/cations species. The pristine CMK-1 and CMK-3 were synthesized by replication using MCM-48 and SBA-15 as hard templates and sucrose as a carbon source. Incorporation of metal species was carried out by wetness impregnation. The mesoporous materials modified were characterized by X-ray diffraction (XRD), X-ray photoelectron spectra (XPS), RAMAN, transmission electron microscopy (TEM), and adsorption/desorption N2 isotherms. Carbon modified with metal/cations shows a better capacity for hydrogen uptake than that of the mesoporous carbons. The evolution of high-pressure hydrogen adsorption measured at 77 K shows that composites can significantly enhance hydrogen adsorption capacity and hydrogen storage performance of carbon materials, proving to be prospective candidates for application in hydrogen storage. The improved activity and the larger performance of composite materials are attributed to improved dispersion of uniform metal/cations nanoparticles as well as to efficient use of the support, which may originate a high-surface area and pore volume, allowing a large dispersion of clusters.