Influence of the rotation rate of porous stainless steel tubes on electroless palladium deposition

Thin dense palladium (Pd) membranes (approximately 5 μm) were fabricated on rotating porous stainless steel supports using electroless plating. During electroless Pd plating, the rate of Pd deposition increased as the support rotation rate increased. Compared with conventional electroless plating methods, the proposed modified electroless plating using a support rotation technique yielded Pd membranes that had considerably more uniform and smooth surface morphology, which substantially enhanced the membrane stability. The membranes exhibited a hydrogen permeance as high as 78 m3/m2 h bar0.5 (3.0×10−3 mol/m2 s Pa0.5) and an ideal permselectivity exceeding 400 when the pressure difference was 4 bar and the temperature was 400 °C. Moreover, the membranes were stable during long-term temperature cycling performed between room temperature and 400 °C over a period of 350 h. These results indicated that the electroless plating combined with support rotation process was a simple, effective method for preparing thin dense Pd membranes featuring high hydrogen permeation flux and high thermal durability.