On the relative stabilities of zeolitic silicas

Abstract A simple quantum‐chemical calculation method has been used to obtain a first estimate of the relative stabilities of zeolitic silicas. When applied to dealuminated faujasite, mordenite and ZSM‐5, the method indicated faujasite to be less stable than mordenite and ZSM‐5. However, the calculated differences in heat of formation between the dealuminated zeolites are very small. Hence, care must be taken in drawing any definite conclusions, particularly in view of the rather approximate nature of the calculation method.