Hydrogen permeation in palladium-based membranes in the presence of carbon monoxide

• DOI: 10.1016/j.memsci.2010.06.055
• Publication Date: 2010-07-06T08:28:41Z
• Authors: Jacopo Catalano; Marco Giacinti Ba...; Giulio C. Sarti
• Keywords: Inert gas; Hydrogen purifier

Abstract A theoretical model is proposed to describe hydrogen permeation in palladium and silver–palladium membranes in presence of a non-inert gas as CO; it is known indeed that hydrogen flux through palladium-based membranes drastically decreases when H 2 is fed in mixtures containing carbon monoxide due to the interaction of the latter gas with the membrane surface. To model this process, the adsorption step of the well-known approach suggested by Ward and Dao has been suitably modified, since it must be considered as a competitive adsorption of the different non-inert molecules on the metal interface. In particular, the competitive adsorption of CO and H 2 has been examined accounting for the spectrum of information available for CO adsorption on palladium, as well as for hydrogen in palladium and palladium–silver alloys. A validation of the model proposed has been performed through a comparison between several literature data and model calculations, over a rather broad range of operating conditions. A quite good agreement was obtained in the different cases; the model, thus, can be profitably used for predictive purposes.