INCAPE   05401
INSTITUTO DE INVESTIGACIONES EN CATALISIS Y PETROQUIMICA "ING. JOSE MIGUEL PARERA"
Unidad Ejecutora - UE
artículos
Título:
PdCuAu ternary alloy membranes: Hydrogen permeation properties in the presence of H2S
Autor/es:
ANA TARDITI; CAROLINA IMOFF; FERNANDO BRAUN; JAMES MILLER, ANDREW GELLMAN; LAURA CORNAGLIA
Revista:
JOURNAL OF MEMBRANE SCIENCE
Editorial:
ELSEVIER SCIENCE BV
Referencias:
Lugar: Amsterdam; Año: 2015 vol. 479 p. 246 - 255
ISSN:
0376-7388
Resumen:
PdCuAuternary alloy membranes with different component compositions were synthesized bysequential electroless deposition on top of porous stainless steel substrates.  The ternary with the highest Au content, Pd69Cu14Au17,exhibited the highest hydrogen permeation flux, comparable to that of a Pd91Au9 membrane.  Upon exposure to 100 ppm H2S/H2at 400°C for 24 h, all PdCuAu membranes experienced flux reductions of ~ 55 %,followed by recovery to ~ 80% of the initial hydrogen flux upon reintroductionof pure hydrogen at 400°C.  Complete fluxrecovery after H2S exposure required hydrogen treatment at 500°C.  XRD analysis of the H2S-exposed PdCuAumembranes revealed fcc alloy structure with no evidence of bulk sulphideformation.  In agreement with the XRD results, sulfur was notdetected in the bulk of H2S-exposed samples by EDS.  However, analysis of H2S-exposed PdCuAu alloys by XPS-depthprofiling revealed low, but measureable, amounts of sulfur in the near-surfaceregion, about 10 nm in depth.  The depthprofiles of samples after hydrogen recovery treatment showed significantlyreduced sulfur content.  These results indicatethat H2S exposure causes flux loss in PdCuAu alloys through asurface-poisoning mechanism, and that the surface sulfide can be removed?andflux recovered?by high temperature treatment in H2.