Micromachined Palladium - Silver Alloy Membranes for Hydrogen Separation

This paper presents wafer-scale palladium silver alloy membranes, fabricated with a sequence of wellknown thin film and silicon micromachining techniques. The membranes have been tested in a gas permeation system to determine the hydrogen permeability and hydrogen selectivity. Typical flow rates of 1 mol H2 /m.s have been measured with a minimal selectivity of 1500 for H2/He. The membranes have high mechanical strength and can withstand pressures up to 4 bars at room temperature. These membranes have the potential to be used for hydrogen purification and other applications such as membrane reactors for hydrogenation/dehydrogenation reactions. The presented fabrication method also allows the development of a module for industrial applications that consists of a stack with a large number of glass/membrane plates