HZSM-5 synthesized from montmorillonite activated by different method as an efficient solid acid for steam reforming of dimethyl ether

A series of HZSM-5 with varying structures and acidities were successfully synthesized from montmorillonite activated via thermally activated, alkali-thermally activated, sub-molten salt-activated, and acid-activated methods. Meanwhile, HZSM-5 used as solid acid was physically mixed with commercial Cu/ZnO/Al₂O₃ catalyst to obtain a bifunctional catalyst for steam reforming of dimethyl ether (SRD) reaction. The samples were characterized by means of XRD, FTIR, SEM, N₂ adsorption desorption, and NH₃-TPD. The results demonstrated that the structure and acidity of HZSM-5 could be effectively regulated by montmorillonite activation method, and then influencing the SRD reaction performance of corresponding bifunctional catalysts. Among them, the bifunctional catalyst composed of HZSM-5 synthesized via using montmorillonite activated by sub-molten salt method and Cu/ZnO/Al₂O₃ exhibited the most favorable SRD performance, and the initial dimethyl ether conversion and H₂ yield reached about 100% and 91% under the conditions of reaction temperature 300 °C, pressure 0.1 MPa, gas hourly space velocity 5000 mL/(g·h), respectively, furthermore, they remained almost constant throughout the reaction period, indicating that the catalyst exhibited good stability.