Synthesis of nanosized HZSM-5 zeolite under microwave irradiation: effect of the Si/Al ratio on the morphology, textural and acidic properties

The effect of the Si/Al ratio on morphology, textural and acidic properties of nanosized ZSM-5 zeolite synthesized by the one-stage microwave hydrothermal method directly in a proton form has been established. The materials were characterized by the X-ray diffraction, scanning electron microscopy, transmission electron microscopy, N₂ sorption, inductively coupled plasma optical emission spectrometry (ICP-OES) and thermal desorption of ammonia. It was found that with a decrease in the Si/Al ratio from 270 to 46, the total acidity increases from 90 to 542 μmol g^–1 and the particle size decreases from 150 to 15–25 nm; at the same time, the particles assemble into larger aggregates.