Preparation and surface hydrophilic modification of MOR zeolite membrane potentially appling for acetic acid aldol condensation reaction system

High-performance MOR zeolite membranes were prepared by loading hydrophilic metal oxides onto the surface of α-Al2O3 support via secondary hydrothermal synthesis method. The effects on the surface morphology and hydrophilicity of MOR zeolite membranes were discussed by means of different metal oxides (TiO2, V2O5, CeO2, ZrO2, WO3) and loadings in combination with SEM, XRD, Raman and Water Contact Angle (WCA) characterization. TiO2-MOR zeolite composite membranes were found that TiO2 could increase interface hydrophilicity. The pervaporation performances of TiO2-MOR zeolite membranes at different temperatures and feed concentrations were investigated. The mass transfer model combining Maxwell-Stefan mechanism, Kundsen diffusion and viscous flow was used to describe the mass transfer process of water molecules through the zeolite layer, and within the α-Al2O3 scaffolds, respectively. The permeation fluxes of water molecules of TiO2-MOR zeolite membranes with the loading of 2 wt% were 0.91 kg m−2 h−1, 1.00 kg m−2 h−1 and the separation factors were up to 10000 at 348 K with 90 wt% AcOH/H2O and 90 wt% AA/H2O solutions. TiO2-MOR zeolite membranes with well acid resistance and high hydrophilicity had promising prospects in the reaction scene where carboxylic acid and water exist simultaneously, such as esterification, ester hydrolysis, acetic acid aldol condensation, etc.