In this work was studied the acid properties of a series of HZSM-12 zeolites with different Si/Al molar ratio. The samples
of ZSM-12 were synthesized by the hydrothermal method starting from a gel with the following molar composition: 20MTEA:10Na2O:xAl2O3:100SiO2:200H2O, where: x=2, 1, 0.67 and 0.50, respectively. After the synthesis, the samples of ZSM-12 were ion-exchanged NH4Cl solution to obtain zeolite in the acid form (HZSM-12). The acid properties were evaluated by n-butylamine thermodesorption in a TG equipment at three different heating rates. The model-free kinetic model was applied
in the TG integral curves to estimate the apparent activation energy (Ea) of the n-butylamine desorption process. The results obtained showed that the HZSM-12 zeolite presents two kinds main of
acid sites: one with Ea in the range of 115-125 kJ mol-1 classified as weak and other kind with Ea varying of 230-250 kJ mol-1 classified as strong.