The difference in the acidic strength of the BAS in these zeolites can be clearly seen in O-H vibrational frequency and local structure of BAS. Although the difference in acidity is in line with the trend in the free energy barriers, potential energy barriers for the same reaction are unaffected by the difference in acidity. Interestingly, we find that the major reason for the difference in the free energy barriers is the entropy of the reactant state. Acidity and local structure may have also influenced the entropy of the reactant state. A detailed study such as this on the structure-reactivity relationship of other zeolites types could help in identifying the most efficient zeolite-system for the C-H activation reactions.