Needs and trends in rational synthesis of zeolitic materials

Abstract

Zeolites are an important class of materials which are widely used in industry as catalysts, adsorbents and ion-exchangers. Their superior properties are closely related to their unique porous framework structure, as well as composition and morphology. The ever-growing needs for zeolitic materials in applications inspire us to think of the rational synthesis of zeolites with desired structures and properties. However, rationalization of zeolitic materials remains one of the most challenging issues in the zeolite research field due to their unclear formation mechanism. Despite this, many efforts have been devoted to synthesize zeolites in a more rational way. In this tutorial review, first, we demonstrate how the geometrical characteristics of zeolite frameworks affect the catalytic performances of the resulting materials; then, we present recent advances in synthetic innovations to target materials, and we further highlight the developments in computer simulations toward ab initio design and synthesis; finally, the future perspective on the rational synthesis of zeolitic materials with desired functions and structures will be described.

Template–Framework Interactions in Tetraethylammonium‐Directed Zeolite Synthesis

“…Although over 230 frameworks are known, economic considerations, of which the cost of the organic templates, referred to as organic structure‐directing agents (OSDAs), dominate, mean only a handful are commercial, even though others could offer superior performance in a given application 3, 4, 5. This has inspired investigations into the complex processes governing the crystallization of MMs, with the goal of supplanting the use of expensive organics 6, 7, 8. The role of OSDAs in MM synthesis falls into three broad categories of templation, structure direction and pore‐filling, depending on the geometric match between the framework and organic, with templation exhibiting a strong geometric match, and pore‐filling showing none 9.…”

Enantiomerically enriched, polycrystalline molecular sieves

“…Upon removal of the OSDA, the microporous void space that is created can be exploited in a variety of applications (i.e., catalysis, separations, ion exchange, and adsorption) (5). These microporous, polycrystalline materials are 3D networks of oxide tetrahedra [zeolites contain only silicon and aluminum, whereas zeolite-like molecular sieves can have a broader range of elements (1)(2)(3)(4)(5)] that create highly ordered, hydrothermally stable framework structures with pores of sizes less than 2 nm. Molecular sieves provide shape-selective properties and, coupled with the inclusion of catalytic active sites, are capable of innumerable highly selective chemical reactions.…”

“…chirality | zeolite | asymmetric catalysis | chiral adsorption T he synthesis of zeolites and zeolite-like molecular sieves has been accomplished using organic structure-directing agents (OSDAs) (1)(2)(3)(4). This synthetic method uses an organic molecule (OSDA) to interact with and influence the assembly pathway of the inorganic components to create a crystalline, organicinorganic composite material.…”

A New Microporous Zeolitic Silicoborate (ITQ-52) with Interconnected Small and Medium Pores

“…Zeolites have been applied for gas adsorption, separation, catalysis, encapsulation or controlled release of molecules, among others, some of them are of industrial application. [1][2][3][4][5][6][7][8][9] There is no doubt that this is the driving force for synthesizing new zeolite structures.Most of the zeolites described in the literature have been obtained by employing tetraalkylammonium cations as organic structure directing agents (OSDAs). 10-13 Recently, we have reported a number of new zeolites synthesized by using tetraalkylphosphonium cations 14 15 and ITQ-49 17 ) or phosphazenes (ITQ-47 18 ) as OSDAs.…”

“…Zeolites have been applied for gas adsorption, separation, catalysis, encapsulation or controlled release of molecules, among others, some of them are of industrial application. [1][2][3][4][5][6][7][8][9] There is no doubt that this is the driving force for synthesizing new zeolite structures.…”