Hydrothermal Stability of Molecular Sieves SBA-15 Research

Hydrothermal Stability of Molecular Sieves SBA-15 was studied. It was characterized by N2 adsorption, X-ray diffraction and FT-IR analysis. The results indicated that water, heat and alkaline environments are acidic center caused some of the molecular sieve SBA-15, the influence of the structure of the SBA- 15 mesoporous molecular sieves have some damage, led to the decrease of the pore diameter, specific surface area. This is because the thermal stability of mesoporous molecular sieve is closely related to the silicon hydroxyl condensation. Due to the contraction of silicon hydroxyl, generated the Si-O-Si unit structure, causes the d100. Moderate Si-OH condensation can increase the stability of mesoporous structure, and excessive Si-fuelled by condensation of Ozzie and Harriet channel by Si-O keys tensile force, spacing gradually reduced resulting in progressive collapse of mesoporous structure.