The reactions of n-butane were investigated on a series of cation exchanged and dealuminated zeolite Y loaded with transition metals.
On the basis of TPD patterns of $NH_3$, the number of strong acid sites increased in the order; $NaYPd-HY_{7.6}>Pd-HY_{5.2}>Pd-Lay>Pd-CaY>Pd-NaY$.
The same trend was observed for isobutene formation except that Pd-LaY showed much higher activity. This result indicated that the activities for cracking and isomerization of n-butane were related to the strength and concentration of the acid sites on zeolites.
The cracking products increased with increasing metallic surface areas, which was probably due to the hydrocracking reactions by the adsorbed $H_2$ on metals.
