(785c) Microstructured Palladium Alloys for Purification of Hydrogen

Highly selective metal membranes for hydrogen gas separation possess tremendous potential, with a variety of important applications.  Large stationary purification systems have seen the most interest, for use in ammonia synthesis or in the US Department of Energy’s Coal to Hydrogen initiative.  Additionally, there is interest from the military for smaller systems, to support mobile hydrocarbon reforming for fuel cell applications.  Unfortunately, the widespread adoption of metal membranes has thus far been stymied by their high cost and chemical sensitivity, particularly to sulfur.  

In this work, these challenges are addressed using microfabrication technology.  This reduces the precious metal requirements of the membrane to sub micron levels, while maintaining high selectivity.  The thin palladium membrane is mechanically supported with a nickel honeycomb structure.  As a result, the completed membrane is completely metallic, allowing for superior sealability and thermal cycling durability relative to metallic/ceramic membranes.  Membrane flux, chemical stability and mechanical durability will be presented and discussed.