Carbon capsules with hollow core/mesoporous shell (HCMS) structures have been synthesized (see Figure for schematic) for the first time using solid core/mesoporous shell (SCMS) silica spheres as templates. The capsules have bimodal pore systems consisting of a uniform, tunable, hollow macroscopic core and a mesoporous shell, thus leading to a great variety of possible applications.

Template synthesis of porous materials is one of the most intensively studied research areas in materials chemistry. Since the development of M41S materials by Mobil Oil researchers in 1992, [1,2] many different mesoporous inorganic materials have been prepared using various types of organ-ic templates. [3±6] Porous polymeric and carbon materials have been synthesized using inorganic templates. [7±9] Many porous carbons have been extensively applied in separation and purification technology. [10] They are also used as catalytic supports, chromatography columns, and electrode materials for batteries and capacitors. [11±13] These porous carbons are usually microporous and the production of larger pore-sized mesoporous carbons has been intensively pursued for applications in separation of bulky organic materials and electrode materials. Recently, we have developed new preparative methods to produce mesoporous carbons using inorganic templates such as surfactant-stabilized silica sol particles [14] and mesoporous MCM-48. [15] In particular, the carbon material produced using the MCM-48 template exhibited interesting electrochemical doublelayer capacitance (EDLC) behavior, resulting from regular 3D interconnected mesopores. Difficulty in the synthesis of the template MCM-48 material, however, would hamper the extensive application of mesoporous carbon material. Herein we report the synthesis of a new mesoporous carbon using hexagonal mesoporous silica (HMS) aluminosilicate as a template. With the knowledge gained from this research, we could indirectly elucidate the pore structure of HMS. We also present preliminary results on the EDLC performance of the material.HMS has several advantages over MCM-48 from a synthetic viewpoint: 1) the use of cheap primary alkyl amines as the structure-directing agent; 2) a higher silica recovery yield (>95 %) than MCM-48 (~50 %); 3) a shorter synthesis time (18 h for HMS and 4 days for MCM-48); and 4) no hydrothermal reaction. [16,17] In the first report on HMS the authors claimed that the pore structure of the silica material is similar to that of well-known hexagonal mesoporous MCM-41, but with a much smaller scattering domain size. The small domain size enabled formation of textural pores, along with framework pores from the template. In a later publication, the same group suggested a wormhole-like pore structure for HMS based on transmission electron microscopy (TEM). [17] The pore structure and the pore connectivity of HMS have not yet been elucidated. The pore connectivity of mesoporous materials is important in catalytic and electrochemical applications. By changing the polarity of the reaction solvent, HMS with dominant framework pores has also been synthesized. In our study HMS silica with predominant framework pores (negligible textural pores) has been utilized as a template.The synthetic procedure for the synthesis of mesoporous carbon using HMS as a template is as follows: HMS was prepared by the reported method using the starting reaction mixture in a molar rati...

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Immobilization of biomolecules in tailor-made nanometerscale structures can significantly improve the performance of biocatalytic processes. For efficient biocatalytic processes, it is highly desirable to develop nanostructured materials that enable high loading and long-term stability of the biocatalysts, as well as low mass-transfer resistance. In this regard, inorganic mesoporous materials [1] with well-controlled pore structures have gained much attention as appropriate, high-capacity hosts for biocatalysts. [2][3][4][5] Template synthesis has frequently been used to synthesize novel porous carbon materials.[6] Recently, a new class of nanoporous carbons, ordered mesoporous carbon (OMC), has been synthesized using ordered mesoporous silica materials as COMMUNICATIONS 2828

The synthesis, crystal structure, characterization, and catalytic properties of the novel medium-pore zeolite TNU-9 (framework type TUN), one of the most crystallographically complex zeolites known to date, are described. TNU-9 was found to crystallize under hydrothermal conditions at the expense of a lamellar precursor over a very narrow range of SiO(2)/Al(2)O(3) and NaOH/SiO(2) ratios and in the presence of 1,4-bis(N-methylpyrrolidinium)butane and Na+ ions as structure-directing agents. A combination of molecular modeling and Rietveld refinement using synchrotron powder diffraction data confirms the proposed topology of as-made TNU-9 and suggests three or possibly four different sites for the organic within the complex pore structure. The proton form (H-TNU-9) of this new medium-pore zeolite exhibits exceptionally high hydrothermal stability, as well as very strong acidity. When compared to H-ZSM-5, H-MCM-22, H-mordenite, and H-Beta, H-TNU-9 displays unique shape selectivities for the acid-catalyzed reactions of monoaromatic hydrocarbons such as the disproportionation of toluene and the isomerization and disproportionation of m-xylene. In particular, for the isomerization of m-xylene, the ratio of isomerization to disproportionation increases steadily to values in excess of 50 with prolonged time on stream and a high p/o xylene ratio is observed in the products, achieving a value of ca. 6 after only a short time on stream. These results are rationalized on the basis of the unique pore topology of TNU-9.

Here, we report that synthetic gallosilicate molecular sieves with the NAT topology and Si/Ga ratios close to but slightly higher than 1.50 undergo an in situ transformation under their crystallization conditions. The materials have been studied ex situ by using powder X-ray diffraction, elemental and thermal analyses, and multinuclear MAS NMR. The transformation is characterized by a change in the distribution of Si and Ga of the NAT framework, from a quite (but not completely) disordered phase to a very highly (but not completely) ordered one, accompanied by a change from tetragonal to orthorhombic symmetry. During most of the solution-mediated transformation, no noticeable signs of fresh precipitation, phase segregation, or changes in the chemical composition are detected. Intermediate materials show variations in the degree of Si-Ga ordering and orthorhombic distortion and are not physical mixtures of the disordered and ordered phases. Ab initio calculations strongly suggest a preferential siting of Si in the tetrahedral sites involved in a smaller number of 4-rings in the NAT topology (i.e., the low multiplicity site). The cost of violations of Loewenstein's rule has also been calculated. For this topology and chemical composition the preferential siting and Loewenstein's rule drive together the system to the ordered configuration. A Monte Carlo sampling procedure affords a reasonable model for the initial, mainly disordered state, which fits well within the experimental disorder-order series.

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