THIN PALLADIUM FILM FORMATION ON SHOT PEENING MODIFIED POROUS STAINLESS-STEEL SUBSTRATES

The rapid development of catalytic membrane reactors requires material s with a higher permeability and a better mechanical stability than th e current thick membranes. Pd-based composite membranes supported on p orous stainless steel offer such an alternative. However commercially available porous stainless steel materials have to be further worked t o reduce the surface pore sizes and ensure the formation of thin Pd fi lms in an impervious form. In this work, a shot peening treatment was performed on the surface of a porous stainless steel to modify its sur face pore size. Substrates with effectively reduced surface pore sizes were obtained under mild peening conditions. The permeation behavior of the substrates was examined using argon as the permeation gas. Impe rvious thin palladium films were deposited on the modified porous subs trate surface by electroless plating. Hydrogen permeability through th e resulting membranes was found to be comparable to that of pure palla dium sheets, while the permeation flux was significantly enhanced due to the use of the thin Pd membrane.