A Novel Low Cost Membrane for Recovery of Hydrogen from Fuel Cell Reformates

The principal objective of this Phase II proposal is the development and subsequent commercialization of a low-cost hydrogen purifier designed to be an integral component of a fuel reformer in a proton exchange membrane fuel cell (PEMFC). Power and Energy (P&E) brings to this task a 10 year record of production and sale of more than 1000 commercial hydrogen purifiers in which hydrogen is diffused through palladium membranes to produce long-lived streams of ultra-pure hydrogen. The innovative feature of the proposed device is the reduction of palladium membrane thickness to about a micron, i.e, too thin to be self-supporting in the absence of a substrate which combines high permeability and dimensional stability under stress. Equally important are the properties of the membrane/substrate interface and the orientation of the assembly relative to the direction of reformate flow. Familiarity with the molecular mechanism of hydrogen flow in membranes serves as a guide to assessment of these effects. Various flat-disc substrates composed of sintered nano-sized particulates are currently under investigation during Phase I. During Phase II, the results of these studies will, in part, be the basis of selection of tubular substrates onto which Pd alloy film will be implanted by vapor deposition.