Microfabricated Palladium Membranes Supported On Electroformed Nickel for Hydrogen Purification of Reformate Gases

Portable fuel cell systems running on energy dense hydrocarbon fuels are highly desirable for military applications.  A key process step is conversion of hydrocarbon fuel into a gaseous stream of high purity hydrogen gas that will be oxidized at the fuel cell anode.  One strategy to produce this hydrogen rich stream is using palladium based purification membranes to separate hydrogen gas from other reformation byproducts.   In this work, microfabrication processes are used to engineer a thin film palladium active layer, supported on an electroformed nickel ‘honeycomb’ mechanical support.  The resulting membrane is completely metallic, planar, and is easily modified to incorporate high temperature diffusion barrier layers.   Membrane fabrication methods and hydrogen purification performance are discussed.