Patent ID: 7998247

Claim:
A method of making a gas separation membrane, wherein said method comprises: applying a layer of a noble metal eggshell catalyst to a surface of a porous metal substrate having a thickness in the range of 1 mm to about 25 mm and a porosity in the range of 0.05 to 0.8 to thereby provide a surface treated porous metal substrate, wherein said noble metal eggshell catalyst applied to said porous metal substrate comprises inorganic oxide particles having a median particle size of from 0.01 to 50 μm coated on their outer surface with a metallic layer of a noble metal, said metallic layer having a layer thickness of 0.01 to 2.5 μm and a metal content of from 0.01 to 5 weight percent based on the total weight of the metal-coated inorganic oxide particles; and coating said surface-treated porous substrate with an overlayer of a gas-selective material to thereby provide a coated, surface-treated porous substrate suitable for use as said gas separation membrane.