A highly crystalline layered silicate with three-dimensionally microporous layers

Abstract

Layered silicates with three-dimensional microporosity within the layers have the potential to enable new applications in catalysis, adsorption and ion-exchange. Until now no such materials have been reported. However, here we present the synthesis and structure of AMH-3, a silicate with three-dimensionally microporous layers, obtained in high purity and crystallinity. AMH-3 is composed of silicate layers containing eight-membered rings in all three principal crystal directions, and spaced by strontium cations, sodium cations and water molecules. Because of its three-dimensional pore structure, acid and thermal stability, this layered material could find applications in polymer-silicate composites for membrane applications, for synthesis of combined microporous-mesoporous materials, and for the formation of new zeolites and microporous films. Its existence also opens new possibilities for the synthesis of other layered silicates with multidimensional microporous framework layers.

Zeolite membranes – a review and comparison with MOFs

“…62 These studies on MOF nanosheets draw on earlier concepts of making dispersible exfoliated zeolite nanosheets to apply them as a selective membrane. 23,25,[366][367][368] The same concept is followed when graphene oxide sheets are stacked and form a thin gas selective layer. 61,369 By the sophisticated processing technology, a bricklayer structure of the MOF sheets is formed which is crucial for gas transport through a polymer membrane containing selectively permeable flakes as for the first time proposed in ref.…”

Separation of H₂ and CO₂ Containing Mixtures with Mixed Matrix Membranes Based on Layered Materials

“…Numerous molecular sieving platelets of different nature have been identified as potential filler materials in membrane applications [24,47], and in particular in the preparation of MMMs: layered zeolites (MCM-22P [49], PREFER [50] and Nu-6(1) [51], and their corresponding delaminated zeolites ITQ-2 [43], ITQ-6 [52] and ITQ-18 [53], respectively, or MFI nanosheets [54]); layered silicates (Na and Sr silicate AHM-3 [55]) including the impermeable nanoclays [47,56]; pseudozeolites (layered aluminophosfate, AlPO) [24]; and titanosilicates (JDF-L1) [57]. In Table 1 MMMs prepared with different flakes (layered silicates, zeolites and pseudozeolites) are classified and a detailed discussion will be presented below.…”

A Zinc Phosphate Structure with Unusual Double‐Sheet Layers Templated by a Cobalt Hexaammine Complex

“…Unfortunately, such layers have not been as frequently reported as other layered structures, such as dense nonporous layers and 1D or 2D microporous layers. [2] To the best of our knowledge, only two layered structures contain 3D microporous host frameworks: silicate AMH-3, which has 8-ring apertures in all three principal crystal directions, [2] and K 4 [B 8 Ge 2 O 17 (OH) 2 ], which has intersecting 8-and 9-ring channels. [3] To synthesize materials with micropores, the introduction of a structure-directing agent (SDA) is necessary.…”