Calculations on electrostatic properties of HY zeolite

Abstract

The Madelung potential and field of monopoles and dipoles have been calculated to study the electrostatic effects in HY zeolite. Calculations on the acidity and the vibrational frequency sequence of skeletal OH groups based on pure electrostatics support the conclusions derived from experiments. The electrostatic potential in the large cavity is found to be smaller than in zeolite Y containing a metal cation but larger than that of discrete molecules. Dipoles give an important contribution to the electrostatic potential of supercages but their contribution to the field is negligible. The importance of long-range effects at atomic sites is emphasized.