Isomorphous element substitution in the chabazite-like aluminophosphate framework

Abstract

Thermal investigations and Fenske-Hall SCF MO calculations have been used for studying isomorphous element substitution in the chabazite-like aluminophosphate framework prepared in the presence of tetraethylammonium hydroxide as a template. The thermal measurements show that the temperature at which the template removal occurs increases as the element varies in the Si-Zn-Mn-Co series. The Fenske-Hall SCF MO calculations on model segments of the framework indicate that the trend can be related to an appropriate decrease in basicity of the oxygen atom directly bound to the element.