Temperature-programmed desorption of n-hexane from hydrated HZSM-5 and NH(4)ZSM-5 zeolites

Abstract

Temperature-programmed desorption coupled with mass spectrometer as a detector (TPD), IR and C-13 NMR measurements are used to study the adsorption of n-hexane on hydrated HZSM-5 and NH(4)ZSM-5 zeolites. The C-13 NMR measurements show that n-hexane can access the pore structure of ZSM-5 zeolites previously saturated with water. TPD spectra of n-hexane are monitored in the temperature region 50-300 degrees C, in the case of fully or partially hydrated samples; two-stage desorption of n-hexane is found. Simultaneous desorption of water and n-hexane in the same temperature region are found, in all investigated samples.