Applied Catalysis A: General, Vol.550, 98-104, 2018
Comparative study of n-butane isomerization over SO42-/Al2O3-ZrO2 and HZSM-5 zeolites at low reaction temperatures
The effects of acidity and pore structures of alumina-promoted sulfated zirconia (SZA) and two HZSM-5 zeolites with different SiO2/Al2O3 ratios on reaction properties of n-butane conversion were comparatively investigated. The results demonstrated that monomolecular isomerization reaction predominated at 433-533 K for SZA catalysts and bimolecular pathway predominated at 573-673 K for HZSM-5 zeolites. For both samples, the amount of coke deposits was considerably low. The differences in catalytic behavior were caused by different acid properties and pore structures. The strength and stability of catalytic Bronsted acid sites determine the conversion rate of n-butane and the deactivation rate of catalysts, respectively. While the contributions of mono molecular and bimolecular pathway, as well as the products distributions are depended on the pore structures and influenced by the density of catalytic Bronsted acid sites.