Fabrication and characterization of MEMS based wafer-scale palladium-silver alloy membranes for hydrogen separation and hydrogenation/dehydrogenation reactions

In this paper, a MEMS based wafer-scale palladium-silver alloy membrane (MWSPdAgM) is presented. This membrane has the potential to be used for hydrogen purification and other applications. A palladium-silver alloy layer (Pd-Ag) was prepared by co-sputtering. The thin Pd-Ag alloy has high hydrogen selectivity, high permeation rate as well as high mechanical and chemical stability. Typical flow rates of 0.5 mol H/sub 2//m/sup 2/.s have been measured with a minimal selectivity of 550 for H/sub 2//N/sub 2/. Anodic bonding of thick glass to silicon was used to package the membrane and create a very robust module. The membrane has high mechanical strength and can withstand pressures up to 4 bars at room temperature. The presented fabrication method allows the development of a module for industrial applications that consists of a stack with a large number of glass/membrane plates.