Pd-Ag composite membranes supported on Al2O3 modified porous stainless steel

DAVID YEPES, LAURA CORNAGLIA, SILVIA IRUSTA, EDUARDO LOMBARDO

Rio de Janeiro, Brazil

Congreso; ENPROMER, (Segundo Congreso de Ingenieria Quimica y Cuarto de Ingenieria de Procesos del MERCOSUR); 2005

Universidade Federal do Rio de Janeiro

Composite Pd-Ag membranes supported on modified porous stainless steel substrates have been prepared by sequential electroless plating. To improve the stability of the Pd-Ag alloy, two different intermediate layers of á-Fe2O3 and ã-Al2O3 oxides were employed as diffusion barriers. A new activation method was investigated consisting in the impregnation of a layer of Pd supported ã-Al2O3 to produce the palladium seeds. The membranes were studied by XRD, Auger depth profiling and SEMEPMA. They were tested in a gas permeation system to determine the hydrogen permeability and selectivity. The Pd-Ag /PSS membranes had a good thermal resistance. The membranes prepared with alumina diffusion barrier exhibited an ideal selectivity lower than the Pd-Ag/á-Fe2O3/ PSS ones. However, the hydrogen permeability of the former was two times higher. The Auger depth profiles did not show the presence of Fe in the Pd-Ag film, indicating that the ã-Al2O3 layer effectively blocked the intermetallic diffusion.