Database of Zeolite Structures
 

Framework Type MWW
Reference Material
  Material Name: MCM-22    
 
Chemical Formula:
 
|H2.4Na3.1 | [Al0.4B5.1Si66.5O144]-MWW
 
   
Unit Cell:
 
hexagonal

 P 6/m m m (# 191)
    a' = 14.2080 Å b' = 14.2080 Å c' = 24.9450 Å  
    α' = 90.000° β' = 90.000° γ' = 120.000°  
   
Framework Density:
 
16.5 T/1000 Å3
 
 
Channels:
 
[001] 10 4.0 x 5.5** | [001] 10 4.1 x 5.1**
Dimensionality
  Sorption (molecular cross section > 3.4Å): 2-dimensional
  Topological (pore opening > 6-ring): 2-dimensional
   
References:
  Leonowicz, M.E., Lawton, J.A., Lawton, S.L. and Rubin, M.K.
  "MCM-22: A molecular sieve with two independent multidimensional channel systems"
Science, 264, 1910-1913 (1994)
 
 
Name and Code derivation:
    Mobil Composition of Matter-twenty-two
  MCM-22 (twenty-two)
  MWW
Limiting Rings
 
10-ring viewed normal to [001]
between 'layers'

10-ring viewed normal to [001]
within 'layers'