Abstract: Nafion®-silica nanocomposite membranes were used to concentrate hydrogen peroxide by pervaporation to aid the development of improved membranes. Membranes were fabricated by casting Nafion® solution in dimethylformamide with colloidal silica. Their morphologies and thermomechanical properties were characterized with respect to silica content (5–20 wt%) by transmission electron microscopy, scanning electron microscopy, and dynamic mechanical analysis. Pervaporation was carried out using a feed solution of 70 wt% hydrogen peroxide at 30 °C and a permeate pressure of 0.5 Torr; the membranes were assessed with respect to permeate flux and selectivity. Permeate flux decreased slightly from 6.189 to 5.750 mol/(h∙m2) with increasing silica content; selectivity was increased by 60% compared with recast Nafion® without silica. Parameters for batch-type pervaporation process design, such as the retentate hydrogen peroxide concentration and the yield, were calculated using a mathematical model developed based on a solution-diffusion mechanism. The simulation results demonstrated that the modified Nafion® membranes should require smaller areas and improve pervaporation.