Dependence of presence of defect in γ-Al_2O_3 toplayer on structure of support

摘要

The permeation properties of two types of supports with different pore sizes were investigated with five kinds of gases, i. e. nitrogen, hydrogen, helium, propane and argon. It is indicated that the gas permeation through these supports occur mainly via viscous flow mechanism. γ-Al_2O_3 composite membranes were made on two types of supports by sol-gel technique. The integrity of γ-Al_2O_3 toplayer was checked by gas permeation method. Fur- thermore, the influence of pore size of support on the defects or defect-free of the toplayer was studied.