Catalytic Sol Assisted Dense Pd/γ-Al₂O₃ Membrane using Modified Electroless Plating: Effect of Process on Surface Morphology

Abstract

Palladium membranes are considered ideal for high purity hydrogen separation owing to their infinite selectivity to hydrogen. The key to such selectivity depends on the dense surface of the membrane that suggests absolute non-porous surface morphology. However, preparation of dense palladium membranes irrespective of any deposition technique leads to pit formation which makes synthesis of dense palladium membrane challenging. The current study illustrates the application of electroless plating assisted with novel catalytic sol pre-coating to prepare dense Pd membranes. The surface characterization using field emission scanning electron microscope (FESEM) and atomic force microscopy (AFM) were performed to identify the gaps between dip coating and electroless plating. It was observed that with the use of a dip coated catalytic sol, thinner and well dispersed Pd deposits could be prepared. The porosity of deposited Pd layers does not affect the essential densification property as sol surface underneath dispersed Pd remains dense.