Preparation and characterization of palladium alloy membranes for catalytic membrane reactors

the number of activation cycles has been properly varied, according to the support characteristics. Defect-free deposits 5- to 15-micron thick, with good anchorage on the ceramic supports have been obtained (see Fig. 1). Permeation tests have been performed in a pilot loop on 10 mm O.D., 14 cm long tubular membranes with single gases (H2, He, CO2), up to 380° C. Typical results are shown in Fig. 2. More in detail hydrogen permeation occurs according to the Sievert law (Fig. 3) and both the permeability coefficient and activation energy (Fig. 4) are in agreement with literature data [2,3]. It can be noted, however, that selectivity of hydrogen versus CO2 and He is only approx. 100, due to leakage through the end seals at the metal/ceramic interface.