N-BUTANE HYDROISOMERIZATION OVER PT HZSM-5 CATALYSTS/

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