3D to 2D Routes to Ultrathin and Expanded Zeolitic Materials

Abstract

This contribution reports new methodology we have developed for the disassembly of 3-D UTL framework into 2-D lamellae followed by structure modification including pillaring. This may be widely applicable, particularly to other zeolites that have D4R units present, and so should have great impact also on other porous solids. Specifically, controlled hydrolysis of D4R units in the interlayer space provides individual ultrathin layers with UTL structure by a chemically selective method. Further manipulation of the layers gives a completely novel approach (3D to 2D to pillared) offering hitherto unprecedented opportunities for the preparation of modified zeolites with diverse chemical and structural properties.

Layered zeolitic materials: an approach to designing versatile functional solids

“…It could also be re-converted to 3D zeolite with regular stacking of previously swollen ferrierite-like layers with octylamine (ICP-4), after calcination process, showing the versatility of this type of layered zeolitic precursors ( Figure 29). 196,197 On the contrary, direct calcination of layered precursor ICP-1P, without intercalated organic compounds, only led to a poorly ordered lamellar material (IPC-1).However, in the case of pillared solids, it was possible the formation of undesirable M41S mesoporous amorphous phases, cohabitating with layered ICP-type zeolites due to the strongly alkaline conditions used during the pillarization process in presence of surfactants as swelling agents.…”

Zeolites with Continuously Tuneable Porosity

“…The assembly-disassembly-organization-reassembly (ADOR) mechanism [13][14][15][16] is a new method of zeolite manipulation, in which the selective disassembly of a pre-prepared parent zeolite followed by reassembly can lead to new topologies. The key feature of the parent zeolite is the presence of a hydrolytically sensitive dopant element, especially Ge, [7][8][9][10][11][12][13][14][15][16][17][18][19] incorporated within the framework at a specific site (a double-four-ring (D4R) unit), which allows the chemically selective removal of the units containing the dopant.…”

“…The key feature of the parent zeolite is the presence of a hydrolytically sensitive dopant element, especially Ge, [7][8][9][10][11][12][13][14][15][16][17][18][19] incorporated within the framework at a specific site (a double-four-ring (D4R) unit), which allows the chemically selective removal of the units containing the dopant. [15,16] ADOR has allowed the preparation of two new zeolite materials, IPC-2 and IPC-4.…”

Synthesis of Zeolites Using the ADOR (Assembly-Disassembly-Organization-Reassembly) Route

“…3 Given the great utility of zeolites, there is great interest in developing new routes to novel materials. Such a route is the recently developed ADOR strategy [4][5][6][7] where a parent zeolite is Assembled, then Disassembled and the resulting species Organized in such a way as to allow final Reassembly into a new solid. This makes use of a pre-prepared zeolite that has inherent instability built into its framework, which we can exploit.…”