A FTIR and TPD examination of the distributive properties of acid sites on ZSM-5 zeolite with pyridine as a probe molecule

作者：Jin Fang; Li Yongdan

来源：Catalysis Today, 2009, 145(1-2): 101-107.

DOI：10.1016/j.cattod.2008.06.007

• Fourier transmission infrared spectroscopy
• Temperature programmed desorption
• Pyridines
• Zeolite
• ZSM-5

The amount, type, origin and strength distribution of acid sites on ZSM-5 zeolite were analyzed with pyridine as a probe molecule, and with the aid of FTIR and interrupted-temperature programmed desorption techniques. Desorption activation energy (DAE) was used as a measure of the acid strength. The acid sites were divided into four sets each with a mean strength of DAE 70, 90, 120 and 150 kJ mol(-1). Bronsted (B) sites were found dominant in the set with DAE 150 kJ mol(-1), while Lewis (L) sites prevail for the DAE 120 kJ mol(-1) set. For the other two sets both B and L sites are important. The B sites with DAE 70 kJ mol(-1) were attributed to terminal silanol groups, and the B sites with DAE 90 kJ mol(-1) were due to bridged hydroxyl and extraframework AlOH groups.

• 出版日期2009-7-15
• 单位天津大学