Electroless Pd deposition on a planar porous stainless steel substrate using newly developed plating rig and agitating water bath

Abstract

A new plating bath was developed to prevent palladium plating in the pores of the porous stainless steel support when using plate-type porous substrate. The plating bath, composed of a holder, a rubber O-ring and a bottom, provides very simple assembly and is very effective in preventing palladium plating in the pores of porous stainless steel. The agitation of the plating solution increases plating rate significantly because the agitation improves the external mass transfer of Pd ion and reducing agent to the membrane surface facilitating ~99.7% plating yield of palladium ion. This new plating method carried out at a temperature range of 293 to 298 K provides a very simple and economic membrane manufacturing process. Using a newly developed plating rig, an 88.9-mm diameter membrane was fabricated, and gas permeation tests showed that the hydrogen permeation flux reached ~0.9 mol s−1 m−2 at 873 K and a pressure difference of 300 kPa and selectivity (H2/N2) was ~1,850 at 873 K with a pressure difference of 100 kPa.