Linde Type A

Class: Zeolite, Tectosilicate

Related Materials: Faujasite, Sodalite, Zeolites

Notable Properties: Gas sorption and separations

Crystal Structure of Linde Type A Zeolite. Silicon atoms are teal and red atoms are oxygen. Orange spheres fill the voids of the sodalite cages
Crystal Structure of Linde Type A Zeolite. Silicon atoms are teal and red atoms are oxygen. Orange spheres fill the voids of the sodalite cages
Linde Type A - LTA
Linde Type A T-site structure showing the large central pore that is accessible to guest molecules

Description:

Linde Type A gains a place in the history of materials science as being the first synthetic zeolite to be used commercially. Invented in 1953 by Union Carbide (Linde Air Products was a division of Union Carbide) LTA was originally used as a molecular sieve for the removal of dioxygen impurities from gas streams. The material is still in use industrially today. In the laboratory 5Å, 4Å, and 3Å sieves are used for the removal of organic solvents.

The compound can be described as the linkage of sodalite cages by double four ring (d4r) cages. The parent material has a nominal Si:Al ratio of 1:1 with charge balancing sodium cations and 27 zeolitic water molecules filling the pore space prior to desolvation. The material can be made with a variety of other cations as well including potassium lithium magnesium and calcium. The identity of the metal cations in the material is was dictates the nominal pore size (5Å, 4Å, and 3Å).

 

Topology:

LTA

Formula:

Na12[(AlO2)12(SiO2)12] • 27 H2O

Space Group:

Pm–3m

Unit Cell Parameters:

11.919 Å

Pore Structure:

3D pore structure through with 4.21 Å molecules can diffuse and a large cage 11.05 Å in diameter.

Occurrence:

Synthetic

Links:

Synthesis by R. W. Thompson and K. C. Franklin

Zeomics

Zeolite Database

Article on the history of zeolites

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s