n-butane hydroisomerization over Pt/HZSM-5 catalysts

The influence of calcination and reduction conditions, the metal-incorporation technique, and metal loading on the hydroisomerization of n-butane over bifunctional Pt/HZSM-5 catalysts was studied. Temperature-programmed desorption of ammonia (TPDA), atomic absorption spectroscopy (AA), BET surface area/pore size distributions, chemisorption measurements, temperature-programmed reduction (TPR), and transmission electron microscopy (TEM) techniques were used to characterize the catalysts. The calcination conditions have a significative influence on ion-exchanged catalysts, as they control the final metal distribution. The reduction conditions and the method used for platinum incorporation were found to be important factors that affected both the activity and selectivity of the catalysts. Thus, the highest selectivity to isobutane was achieved over an ion-exchanged catalyst.