Palladium/ruthenium composite membrane for hydrogen separation from the off-gas of solar cell production via chemical vapor deposition
The potential application of palladium-ruthenium composite membranes to the separation of hydrogen from chlorosilane gases in silicon-based industries was investigated. Palladium and palladium-ruthenium composite membranes were deposited on pretreated porous stainless steel substrates by electroless plating. Hydrogen permeation tests and temperature programmed desorption (TPD) analysis revealed that the addition of a Ru overlayer on Pd changed the hydrogen adsorption characteristics, resulting in improved stability of the membrane at low temperatures. The Ru/Pd/Al2O3/PSS composite membrane had a stable hydrogen permeation flux of 1.8 m3 m−2 h−1 over a period of 1200 h at 180 °C without suffering hydrogen embrittlement. After exposure to impurities such as HCl and SiHCl3, the hydrogen permeation flux of the Ru/Pd/Al2O3/PSS composite membrane was stable over a period of 9 h with feed pressure of 2.0 bar at 225 °C. Scanning electron microscopy (SEM), energy dispersive X-ray (EDX), and EDX mapping of the Ru/Pd/Al2O3/PSS membrane after the exposure test showed no surface deposition of Si and Cl.