Akira Taguchi

Bio: Akira Taguchi is an academic researcher from Max Planck Society. The author has contributed to research in topics: Materials science & Hydrogen. The author has an hindex of 7, co-authored 9 publications receiving 2380 citations.

Taking Nanocasting One Step Further: Replicating CMK‐3 as a Silica Material

Abstract: The replication of nanoscale structures by a direct templating process has been used in recent years in several creative ways for the synthesis of carbon replicas of zeolites[1] or ordered mesoporous carbons, such as CMK-1[2] or SNU-1.[3] Such processes rely on the fact that an ordered pore system, provided by the zeolite or ordered mesoporous silica, can be filled with a carbon precursor which is pyrolyzed and the silica leached with NaOH or HF solution. However, the technique is difficult to apply to the synthesis of framework compositions other than carbon, since the leaching of the silica typically also affects the material which is filled into the silica pore system. This problem could possibly be circumvented by not using the silica as the mold, but to instead go one step further and use the mesoporous ordered carbons as templates, which could then easily be removed by combustion or other techniques, as suggested recently.[4] On the macroscale, that is, for the production of photonic crystals, similar approaches are well known, where latex spheres are used as templates which can be removed by calcinations.[5] Also carbon black has been used as a TMtemplate∫, for instance to synthesize mesoporous zeolite single crystals, in which the pores, however, are disordered.[6] In a first attempt to show the feasibility of using ordered mesoporous carbon to synthesize ordered mesoporous oxides, we decided to template mesostructured silica by using an ordered mesoporous carbon. Although this brings one only back to the starting point, that is, a mesoporous silica, it COMMUNICATIONS

Materials encapsulated in porous matrices for the reversible storage of hydrogen

Abstract: High dispersion of hydrogen storage material comprising a component suitable for hydrogen storage purposes selected from alkali alanate, a mixture of aluminum metal with alkali metal and/or alkali metal hydride and magnesium hydride or mixtures thereof, wherein the hydrogen storage component is encapsulated in a porous matrix.

Recent Progress in the Synthesis of Porous Carbon Materials

Abstract: In this review, the progress made in the last ten years concerning the synthesis of porous carbon materials is summarized. Porous carbon materials with various pore sizes and pore structures have been synthesized using several different routes. Microporous activated carbons have been synthesized through the activation process. Ordered microporous carbon materials have been synthesized using zeolites as templates. Mesoporous carbons with a disordered pore structure have been synthesized using various methods, including catalytic activation using metal species, carbonization of polymer/polymer blends, carbonization of organic aerogels, and template synthesis using silica nanoparticles. Ordered mesoporous carbons with various pore structures have been synthesized using mesoporous silica materials such as MCM-48, HMS, SBA-15, MCF, and MSU-X as templates. Ordered mesoporous carbons with graphitic pore walls have been synthesized using soft-carbon sources that can be converted to highly ordered graphite at high temperature. Hierarchically ordered mesoporous carbon materials have been synthesized using various designed silica templates. Some of these mesoporous carbon materials have successfully been used as adsorbents for bulky pollutants, as electrodes for supercapacitors and fuel cells, and as hosts for enzyme immobilization. Ordered macroporous carbon materials have been synthesized using colloidal crystals as templates. One-dimensional carbon nanostructured materials have been fabricated using anodic aluminum oxide (AAO) as a template.

Mesoporous Carbon Materials: Synthesis and Modification

Abstract: Porous carbon materials are of interest in many applications because of their high surface area and physicochemical properties. Conventional syntheses can only produce randomly porous materials, with little control over the pore-size distributions, let alone mesostructures. Recent breakthroughs in the preparation of other porous materials have resulted in the development of methods for the preparation of mesoporous carbon materials with extremely high surface areas and ordered mesostructures, with potential applications as catalysts, separation media, and advanced electronic materials in many scientific disciplines. Current syntheses can be categorized as either hard-template or soft-template methods. Both are examined in this Review along with procedures for surface functionalization of the carbon materials obtained.

Hierarchical zeolites: enhanced utilisation of microporous crystals in catalysis by advances in materials design.

Abstract: The introduction of synthetic zeolites has led to a paradigm shift in catalysis, separations, and adsorption processes, due to their unique properties such as crystallinity, high-surface area, acidity, ion-exchange capacity, and shape-selective character. However, the sole presence of micropores in these materials often imposes intracrystalline diffusion limitations, rendering low utilisation of the zeolite active volume in catalysed reactions. This critical review examines recent advances in the rapidly evolving area of zeolites with improved accessibility and molecular transport. Strategies to enhance catalyst effectiveness essentially comprise the synthesis of zeolites with wide pores and/or with short diffusion length. Available approaches are reviewed according to the principle, versatility, effectiveness, and degree of reality for practical implementation, establishing a firm link between the properties of the resulting materials and the catalytic function. We particularly dwell on the exciting field of hierarchical zeolites, which couple in a single material the catalytic power of micropores and the facilitated access and improved transport consequence of a complementary mesopore network. The carbon templating and desilication routes as examples of bottom-up and top-down methods, respectively, are reviewed in more detail to illustrate the benefits of hierarchical zeolites. Despite encircling the zeolite field, this review stimulates intuition into the design of related porous solids (116 references).

Graphitic carbon nitride materials: controllable synthesis and applications in fuel cells and photocatalysis

Abstract: Graphitic carbon nitrides (g-C3N4) are becoming increasingly significant due to the theoretical prediction of their unusual properties and promising applications ranging from photocatalysis, heterogeneous catalysis, to fuel cells. Recently, a variety of nanostructured and nanoporous g-C3N4 materials have been developed for a wide range of new applications. This feature article gives, at first, an overview on the synthesis of g-C3N4 nanomaterials with controllable structure and morphology, and secondly, presents and categorizes applications of g-C3N4 as multifunctional metal-free catalysts for environmental protection, energy conversion and storage. A special emphasis is placed on the potential applications of nanostructured g-C3N4 in the areas of artificial photocatalysis for hydrogen production, oxygen reduction reaction (ORR) for fuel cells, and metal-free heterogeneous catalysis. Finally, this perspective highlights crucial issues that should be addressed in the future in the aforementioned exciting research areas.