Retrosynthetic Co-Templating Method for the Preparation of Silicoaluminophosphate Molecular Sieves

Abstract

1,5-(1,4-diazabicyclo[2.2.2]octane)pentyl dibromide (diDABCO-C5)13.0 g (0.06 mol) of 1,5-dibromopentane was dissolved in 50 mL ethanol and added droop-wise to a solution under stirring at 50 °C of 33.6 g (0.30 mol) of 1,4-diazabicyclo[2.2.2]octane (DABCO) dissolved in 100 mL ethanol. The mixture was refluxed for 24 hours. Once cold, the excess of ethanol was removed on a rotary evaporator leaving yellow oil. Subsequently cold

STA-20: An ABC-6 Zeotype Structure Prepared by Co-Templating and Solved via a Hypothetical Structure Database and STEM-ADF Imaging

“…prepared with the same co-templates. 30 Most signals observed in STA-20 are closely similar to those non-equivalent C atoms assigned to diDABCO-C6 in STA-20. However, for each expected non-equivalent C in diDABCO-C6 in STA-20, two peaks can be resolved in the spectrum.…”

“…Similar effects were previously observed for co-templated syntheses of SAPOs STA-18 (SFW) and STA-19 (GME). 30 Other materials with frameworks belonging to the ABC-6 family, such as SAPO STA-18 and STA-20, can also be successfully used as seeds for STA-20. We speculate that the similar structural layers present in these materials play a role in the nucleation of STA-20 crystals.…”

“…This was first identified as an impurity in the dual-template synthesis of SAPO STA-18 (SFW), 30 and it has been prepared phase pure by careful optimisation of the synthetic conditions. Its structure is well ordered, but it is prepared in microcrystalline form, precluding structure solution by single crystal X-ray diffraction.…”

Porous aluminophosphates as adsorbents for the separation of CO2/CH4and CH4/N2mixtures – a Monte Carlo simulation study

“…The two additional frameworks are the SFW and the SWY frameworks, which correspond to two silicoaluminophosphates that were recently synthesised by Wright and co-workers (STA-18 -SFW and STA-20 -SWY). 61,62 Like all other structures, these two frameworks were optimised in pure-AlPO 4 composition. The setup of the structure optimisations was chosen on the basis of previous benchmarking work, 63,64 using the CASTEP code with on-the-fly-generated ultrasoft pseudopotentials, 65 the PBE functional 66 in conjunction with the dispersion correction devised by Tkatchenko and Scheffler, 67 and an energy cutoff of 700 eV.…”

Cooperative structure-directing effect of choline cation and *BEA zeolite in the synthesis of aluminogermanosilicate IWR zeolite

“…Based on this premise, we may expect a cooperative structure-directing effect of OSDAs and crystal seeds under certain conditions. Inspired by the cooperative structure-directing effect of two different OSDAs [24][25][26][27][28][29], various syntheses employing a combination of organic molecules and solid seeds have been reported. For example, Valtchev et al [30] reported the "inductive effect" of as-synthesized UTD-1 seeds on the crystallization of SSZ-24 zeolites, where the addition of UTD-1 seeds accelerated the zeolite nucleation and led to the formation of pure and well-crystallized SSZ-24.…”