Porous anodic alumina microreactors for production of hydrogen from ammonia

The synthesis and properties are described of a ruthenium‐impregnated anodic aluminum catalyst for use in microreactors for the production of hydrogen from an ammonia feed. The catalyst structure was synthesized using microelectric discharge machining to create a series of 300 × 300‐μm posts on an aluminum substrate. The posts were anodized to yield a 60‐μm covering of anodic alumina, with an average surface area of 16 m 2 /gm and an average pore size of 50 nm. Ruthenium metal was dispersed on the alumina using conventional wet impregnation. A 0.9 × 0.9‐cm reactor containing 250 posts decomposed 95% of anhydrous ammonia at 650°C to yield 15 sccm of hydrogen. A possible application of these microreactor fabrication methods is hydrogen generation for fuel cells in mobile power production. 2004 American Institute of Chemical Engineers AIChE J , 50:829–834, 2004