Zeolite Chemistry VII-Framework Substitution for Aluminum in Zeolites VIA Secondary Synthesis Treatment.

Synthesis of Sn–silicalite from hydrothermal conversion of SiO2–SnO2 xerogels

“…The interest of tin incorporation into zeolites dates from decades ago [1]- [3]. In these first articles, the substitution of Si by Sn into zeolite frameworks, particularly in MFI materials, was supported by different characterization techniques.…”

Environmental Applications of Zeolites: Hydrophobic Sn-BEA as a Selective Gas Sensor for Exhaust Fumes

“…All MAS NMR spectra were recorded using a 4mm MAS probe-head at a spinning rate of 12 kHz. Adsorption of trimethylphosphine oxide (TMPO, (CH 3 ) 3 PO, Aldrich, Gillingham, UK) as a probe-molecule was followed by 31 P NMR under 1 H decoupling. Samples were dehydrated at 400 • C under vacuum (~4 × 10 −5 Torr) while a solution of TMPO in dichloromethane was prepared.…”

“…The suspension was dried by evaporating the solvent under vacuum for 2 h. The TMPO-loaded zeolites were then packed in zirconium rotors for the NMR characterisation. 31 P π/2 and π-pulses lengths were 7 and 14 µs, respectively, for all measurements.…”

“…Figure S9. 31 P MAS NMR spectra of TMPO adsorbed on Sn-BEA (1) and DeAl-BEA (2, intensity is multiplied by a factor of 50) zeolites. Figure S10.…”

“…An alternative way of zeolite modification is by isomorphous substitution, that is incorporating other metals (Ti, Ga, Zr, Sn) [17][18][19][20][21][22] into the framework structure instead of aluminium. These metal-containing zeolites are extensively used in heterogeneous catalysis, including some of the commercially exploited framework types, such as BEA, MFI, CHA, and FAU [22][23][24][25][26][27][28][29][30][31]. For instance, Sn-containing BEA zeolites are highly selective catalysts in biomass conversion: enhanced activity and product selectivity were reported in Meerwin-Pondorf-Verlein reduction [20], Baeyer-Villiger oxidation [22], sugar isomerisation [23][24][25][26][27][28], and epimerisation [23,32].…”