Tatsuya Okubo 교수

Organic structure-directing agent (OSDA)-free synthesis of zeolite beta is a subject of both scientific and industrial interest. Herein, we report a comprehensive investigation into the effects of various parameters on the seed-assisted crystallization of zeolite beta in the absence of OSDA. The crystallization behavior of "OSDA-free beta" is strongly governed by the chemical composition of the starting Na(+)-aluminosilicate gel as well as by the Si/Al ratios of the calcined beta seed crystals,

Characteristics of zeolite formation, such as being kinetically slow and thermodynamically metastable, are the main bottlenecks that obstruct a fast zeolite synthesis. We present an ultrafast route, the first of its kind, to synthesize high-silica zeolite SSZ-13 in 10 min, instead of the several days usually required. Fast heating in a tubular reactor helps avoid thermal lag, and the synergistic effect of addition of a SSZ-13 seed, choice of the proper aluminum source, and employment of high tem

Make intergrowth, not war! Hierarchically organized MFI zeolites with micro-, meso-, and macroporosity (see scheme) in one structure were made by sequential intergrowth by using a simple organic structure-directing agent (OSDA) without meso- or macroporogens. The use of an OSDA that imperfectly fits the zeolite framework generated very thin zeolite plates with 90° rotational intergrowth.

Zeolites have been successfully employed in many catalytic reactions of industrial relevance. The severe conditions required in some processes, where high temperatures are frequently combined with the presence of steam, highlight the need of considering the evolution of the catalyst structure during the reaction. This review attempts to summarize the recently developed strategies to improve the hydrothermal framework stability of zeolites.

Abstract Uniform‐sized silica nanospheres (SNSs) assembled into close‐packed structures were used as a primary template for ordered porous graphitic carbon nitride (g‐C 3 N 4 ), which was subsequently used as a hard template to generate regularly arranged Ta 3 N 5 nanoparticles of well‐controlled size. Inverse opal g‐C 3 N 4 structures with the uniform pore size of 20–80 nm were synthesized by polymerization of cyanamide and subsequent dissolution of the SNSs with an aqueous HF solution. Back‐fi

An ultrafast route was established to synthesize industrially important zeolites in several minutes, which represents a breakthrough in the field of zeolite synthesis.

The structure of amorphous precursor species formed under hydrothermal conditions, prior to the onset of crystallization of microporous aluminosilicate zeolites, is determined employing high-energy X-ray diffraction (HEXRD). The investigation, combined with the use of reverse Monte Carlo modelling suggests that even numbered rings, especially 4R (R: ring) and 6R, which are the dominant aluminosilicate rings in zeolite A, have already been produced in the precursor. The model implies that the for