ITQ-12: a new microporous silica polymorph potentially useful for light hydrocarbon separationsElectronic supplementary information (ESI) available: details of the structure solution, Rietveld refinements in space groups C2/m and Cm and energy minimisation calculations in C2/m, Cm and C2. See http://www.rsc.org/suppdata/cc/b3/b306440a/

Abstract

The new synthetic form of microporous crystalline silica, denoted as ITQ-12, shows a high potential for the separation of propane and propene from its mixtures.

Crystalline oxyfluorinated open-framework compounds: Silicates, metal phosphates, metal fluorides and metal-organic frameworks (MOF)

“…In other topologies (octadecasil-type AST [27], ITQ-12 ( Fig. 2) [28], ITQ-13 [29], etc. ), fluorine is encapsulated within small cubic D4R cages (double 4-ring containing eight silicon atoms at the corner of a cube T 8 O 20 ).…”

“…Corma (Valencia, Spain) and Patarin (Mulhouse, France) described new architectures with systems of inter-crossing channels bound by 10, 12 or 14 TO 4 units (ITQ-n materials [28,[31][32][33], IM-10 [34], IM-12 [35]). It seems that the addition of germanium together with fluorine favours the formation of new open-frameworks based on the D4R units ( 19 F NMR signature at %À10 ppm), whilst the pure silica analogues do not exist for some of them.…”

Cu-BTC and Fe-BTC metal-organic frameworks: Role of the materials structural features on their performance for volatile hydrocarbons separation

“…In this sense, the selection of appropriate adsorbent has been a priority for decades [6]. Activated carbons, zeolites, silica and alumina have been evaluated, with well performance only for some cation-free zeolites [7][8][9][10][11][12]. More recently, the preparation and characterization of metal-organic frameworks (MOFs) have opened new opportunities in the search of highly efficient materials for adsorptive separation of light hydrocarbons [3,[13][14][15][16][17].…”

Synthesis Approaches

“…Alkylation of substituted imidazoles has also been investigated and has been found to give mainly one-dimensional zeolites such as MTW, TON, and MTT [104]. Later, substituted imidazoles were found to make three new zeolites, ITQ-12 (ITW) in the presence of HF [41], SSZ-70 (structure unknown) in the presence of boron [105], and IM-16 (UOS) in the presence of germanium [65]. The CoAPO, SIZ-7 [106] (SIV), was also prepared with an imidazolium template.…”