Towards an integrated ceramic micro-membrane network: Electroless-plated palladium membranes in cordierite supports

In this manuscript the authors detail the fabrication of permselective palladium membranes within cordierite mini-channel networks, and their subsequent evaluation for hydrogen purification. Cordierite extruded honeycomb monoliths (64 cpsi) were first washcoated with micropowder γ-Al2O3 to realize cylindrical surfaces for subsequent deposition of palladium films. A second nanopowder γ-Al2O3 layer provides a uniform surface for deposition of defect-free palladium films. Electroless plating under kinetic-limited conditions enabled plating of thin (8 μm) defect-free palladium films with crystallite sizes of ∼2 μm. Analysis of resulting two-channel membrane systems for hydrogen separation at 350 °C demonstrated hydrogen flux of 1.0–5.5 × 10−3 mol m−2 s−1 and hydrogen-to-helium selectivities of 40–360:1. Lastly, the authors detail a novel microreactor design strategy to employ resulting mini-channel membrane networks as part of a thermally integrated portable reformer for high-purity hydrogen production.