Abstract
Abstract Increasing the service life and reducing the cost of inorganic hydrogen permeable selective membranes are important tasks of membrane technologies. To do this, it is necessary to create membranes in which the use of palladium will be minimized, providing high hydrogen permeability and stability, the required level of performance, and manufacturability. Here, the possibility of replacing palladium catalytic layers with layers of nickel and cobalt is considered using the example of symmetric tantalum membranes. The results of the influence of the composition and thickness of the catalytic layers on the hydrogen permeability of membranes and the period of their operation until destruction under test conditions at 580°С and a hydrogen pressure drop of 500–100 kPa are presented. It is shown that one of the reasons for the premature destruction of Pd/Ta/Pd membranes is oxidation, which develops at the catalytic layer/tantalum interface from the inlet side. The reasons for its occurrence under the conditions of membrane operation in an atmosphere containing corrosive gases are substantiated. Experimental results are presented, indicating that catalytic layers of nickel on the surface of membranes at a certain thickness ensure their high hydrogen permeability, stability of hydrogen flow, and duration of operation. This makes nickel a promising material to substitute for palladium in membranes for certain applications. Cobalt-based catalytic layers are unable to provide a high hydrogen permeability of membranes because of low catalytic activity during dissociative–associative hydrogen processes occurring on the membrane surface.