Thin palladium membrane microreactors with oxidized porous silicon support and their application

We microfabricated a MEMS (micro electro mechanical system)-based thin palladium (Pd) membrane microreactor with oxidized porous silicon (PS) support. The membranes were characterized by permeation experiments with hydrogen, nitrogen and helium at temperatures ranging from 200 °C to 250 °C. The hydrogen flux through the Pd membrane with a thickness of 340 nm was 0.112 mol m^-2 s^-1 at 250 °C and a partial pressure difference of 212 kPa. H₂/N₂ and H₂/He selectivity was about 44 and 10 at 250 °C, respectively. The thermal isolation of the Pd membrane, which was heated by an integrated microheater, was realized by using the oxidized PS ring. We also carried out the hydrogenation of 1-butene at 250 °C using the developed microreactor. The conversion of 1-butene of 100% was obtained at low flow rate of 1-butene. The results show that microreactors have a potential to be used in hydrogen purification and hydrogenation.