The acid properties of H-ZSM-5 as studied by NH3-TPD and 27Al-MAS-NMR spectroscopy The acid properties of H-ZSM-5 zeolites with different SiO 2/Al 2O 3 ratios (30, 50, 80, 150, 280 and 1000) were examined by means of the temperature progr... L Rodríguez-González,F Hermes,M ...