This report summarizes progress made during the a three year University Coal Research grant (DE-FG26-03NT41792) at the Colorado School of Mines. The period of performance was September 1, 2003 through August of 2006. We made excellent progress toward our goal of contributing to the development of high productivity, sulfur tolerant composite metal membranes for hydrogen production and membrane reactors. Composite Pd and Pd alloy metal membranes with thin metal films (1-7 µm) were prepared on porous stainless steel and ceramic supports that meet or exceed the DOE 2010 and 2015 pure hydrogen flux targets at differential pressure of only 20 psi. For example, a 2 µm pure Pd membrane on a Pall AccuSep® substrate achieved an ideal H 2 /N 2 separation factor of over 6000, with a pure hydrogen flux of 210 SCFH/ft 2 at only 20 psig feed pressure. Similar performance was achieved with a Pd 80 Au 20 composite membrane on a similar stainless steel substrate. Extrapolating the pure hydrogen flux of this PdAu membrane to the DOE Fossil Energy target conditions of 150 psia feed pressure and 50 psia permeate pressure gives a value of 508 SCFH/ft 2 , exceeding the 2015 target. At these thicknesses, it is the support cost that will dominate the cost of a large scale module. In a direct comparison of FCC phase PdCu and PdAu alloys on identical supports, we showed that a Pd 85 Au 15 (mass %) alloy membrane is not inhibited by CO, CO 2 , or steam present in a water-gas shift feed mixture at 400 °C, has better resistance to sulfur than a Pd 94 Cu 6 membrane, and has over twice the hydrogen permeance.

This report summarizes progress made during the second year of research funding from DOE Grant # DE-FG26-03NT41792 at the Colorado School of Mines. The period of performance was September 1, 2004 through August of 2005. We have reformulated our Pd plating process to minimize the presence of carbon contamination in our membranes. This has improved durability and increased permeability. We have developed techniques for plating the outside diameter of ceramic and metal substrate tubes. This configuration has numerous advantages including a 40% increase in specific surface area, the ability to assay the alloy composition non-destructively, the ability to potentially repair defects in the plated surface, and the ability to visually examine the plated surfaces. These improvements have allowed us to already meet the 2007 DOE Fossil Energy pure H 2 flux target of 100 SCFH/ft 2 for a hydrogen partial pressure difference of 100 psi with several Pd-Cu alloy membranes on ceramic microfilter supports. Our highest pure H 2 flux on inexpensive, porous alumina support tubes at the DOE target conditions is 215 SCFH/ft 2 . Progress toward meeting the other DOE Fossil Energy performance targets is also summarized. Additionally, we have adapted our membrane fabrication procedure to apply Pd and Pd alloy films to commercially available porous stainless steel substrates. Stable performance of Pd-Cu films on stainless steel substrates was demonstrated over a three week period at 400 °C. Finally, we have fabricated and tested Pd-Au alloy membranes. These membranes also exceed both the 2007 and 2010 DOE pure H 2 flux targes and exhibit ideal H 2 /N 2 selectivities of over 1000 at partial pressure difference of 100 psi 4