PREPARATION OF COMPOSITE PALLADIUM MEMBRANES USING ETCHING PROCESS OF METAL CHLORIDES

摘要

To provide a preparation method of a composite palladium membrane for hydrogen gas separation, wherein selective separability and permeability of hydrogen gas relative to nitrogen gas are increased, and flow of the nitrogen gas is minimized. In a method for preparing a composite palladium membrane for hydrogen gas separation prepared by coating a palladium thin film on the surface of a porous supporting body, the method comprises the step of heat treating the composite palladium membrane in a temperature range of 300 to 500 deg.C after etching the prepared composite palladium membrane using a solution of quadrivalent metal chlorides, wherein the quadrivalent metal chlorides are selected from TiCl4, VCl4, SnCl4, PtCl4, SeCl4, SiCl4, TeCl4, WCl4 and ZrCl4, wherein the solution of quadrivalent metal chlorides an aqueous solution or an alcohol solution containing 0.05 to 0.8 molar concentration of metal chlorides, wherein the etching process is performed for 5 to 60 minutes, wherein the porous supporting body is a flat membrane, a hollow fiber membrane or tube formed of a material selected from ceramic, glass and stainless steel having a pore size ranging from 0.01 to 1 mum, and wherein the palladium thin film is coated with palladium alone or an alloy consisting of palladium and one or more metals selected from silver(Ag), copper(Cu), iron(Fe), titanium(Ti), yttrium(Y) and ruthenium(Ru).