This research is focussed on the development of a reactor system with semi-permeable walls that will permit both reaction and selective separation to occur simultaneously. The advantage of such a system for equilibrium-bound chemistries is obvious. The research plan involves the development of a technique for coating the porous ceramic walls of a reactor with a suitable diffusion promoter, palladium, measurement of transport properties, and modelling studies of the unique reactor combined with a demonstration reaction of significance. Specifically, project is aimed at developing palladium/porous ceramic oxide composites for the economical separation of hydrogen from high temperature gas mixtures. Particular applications envisioned include in situ removal of hydrogen from reactive mixtures in which there is normally an equilibrium limitation on conversion. This will be demonstrated in experiments in which catalytic steam reforming of methane will be undertaken in a tubular reactor with a Pd/ceramic composite wall. In addition to the development of a practical means of supporting thin Pd films on porous substrate, and demonstrating their applications to reaction- separation coupling, the study will examine rigorously the mechanism of hydrogen transport across such films, and determine at what temperatures, pressures, and film thicknesses the process is controlled by hydrogen dissociation/re-association, versus interstitial diffusion of hydrogen atoms.
