ACTIVATION-ENERGY FOR THE DECAPSULATION OF SMALL MOLECULES FROM A-TYPE ZEOLITES

Potential energy function sets for some ion-exchanged A-type zeolites, K-A and Rb11Na1-A, were determined by introducing the X-ray crystal s tructures as constraints. The potential functions reproduced well the X-ray crystal structures of the monovalent ion-exchanged zeolites. The activation energies for the en- or decapsulation of small molecules ( H-2, O-2, N-2, and CH4) and inert gases from the alpha-cage of model z eolites (Na-A, K-A, Rb11Na1-A, and Cs3Na9-A) were obtained by the mole cular mechanical calculations. The calculated activation energies agre ed well with experimental results.