LEV

[B]-Levyne

Si(89), B(11)

 

Contributed by: Giuseppe Bellussi and Angela Carati
       
Verified by: Li Shi and by S. B. Hong
       
Type Material: (Na,H)5[B5Si49O108] :8 Q: 5 H2O a (Q= quinuclidine)
       
Method: R Millini, A. Carati, G. Bellussi [1]
       
Batch Composition: 3.0 Q: B2O3 : 3.0 SiO2 : 60 H2O
       
Source Materials  
  distilled water
quinuclidine (1-azabicyclo[2.2.2]octane) (Aldrich, 97%)
boric acid (H3B03) (Carlo Erba RPE-ACS)
silica sol (Dupont HS-40, 40% SiO2, 0.3% Na2O)
       
Batch Preparation (for 19 g dry product)
  (1) (10 g water + 14.7 g quinuclidine], mix until dissolved
(2) [61 g water + 10.8 g boric acid + 14.7 g quinucidine], mix until dissolved
(3) [39.5 g silica sol + (1)], mix until a uniform gel is obtained
(4) [(3) + (2)], add solution (2) to gel slowly with vigorous mixing. Final slurry pH ~ 11
       
Crystallization  
  Vessel: stainless-steel autoclave
Time: 5 days
Temperature: 170oC
Agitation: autoclave is rotated 20 rpm
       
Product Recovery  
  (1) Filter to recover solids
(2) Wash with distilled water
(3) Dry at l20oC
(4) Yield: 90% on SiO2
       
Product Characterization  
  XRD: LEV (only crystalline phase), a = 12.944 Å, c = 2 1.914 Å
Elemental Analysis: 17 SiO2: B2O3: 2.7 Q(dry basis)b
Crystal Size and Habit: Compact spherical aggregates (4 to 8 um) of small crystals
       
Reference  
  [1] R. Mimi, A. Carati, G. Beilussi, Zeolites 12 (1992) 265
       
Notes  
  a Protonated quinuclidine (HQ+) or Na+ (from silica sol) act as counterions for structural boron.
b By thermal analysis, organic material adsorbed in extra framework pores is eliminated at 268oC. After treatment at 550oC for a few hours, a limited structure collapse is observed with formation of amorphous material and trigonal BO3 units. [1]