OP-II-3

PP-III-14COMPARISON OF Pd-BASED MEMBRANES WITH DIFFERENTINTERMEDIATE LAYERS FOR HYDROGEN PRODUCTIONCorengia P. 1 , Fernandez E. 1 , Calles, J.A. 2 , Sanz R. 2 , Alique D. 21 INASMET-TecnaliaMikeletegi Pasealekua 2, 20009 San Sebastián, Donostia, SpainE-mail: pablo.corengia@inasmet.es2 Department of Chemical and Energy Technology, Universidad Rey Juan Carlosc/Tulipán s/n, 28933 Móstoles, Madrid, SpainNowadays, the global interest in developing the hydrogen economy is generatingan important research activity for optimization hydrogen production processes. In thiscontext, Pd-based membranes represent a suitable alternative for hydrogenseparation and membrane reactor applications [1]. Nevertheless, pure Pdmembranes present some important drawbacks such as H 2 embrittlement andpoisoning by sulfur compounds for its industrial application. These problems can besolved alloying the Pd membrane with other metals, mainly Ag or Cu. Instead ofpreparing a thick Pd-based foil (high Pd cost and poor permeation properties), anadvisable alternative is the production of a Pd-based composite membraneconsisting of a thin selective layer (Pd or its alloy) deposited onto a porous support.There is a large variety of techniques for obtaining composite Pd-based membranesover different supports, including electroless plating, electroplating, chemical vapourdeposition or physical vapour deposition. Attending the economy of the covering,electroless plating (ELP) is one of the most attractive techniques due to theirsimplicity, facility for covering complex geometries and ease to scale-up [2].However, Physical Vapour Deposition (PVD) is less laborious, provides fasterdeposition rates, allows better control of the film thickness and alloy composition, andalso is an eco-friendly dry process [3,4]. In the case of using a metallic support, thedeposition of an additional layer is necessary for avoiding the intermetallic diffusionbetween compounds of the support and Pd-based layer at high temperatures.Tungsten, tungsten oxide, tantalum oxide, iron oxide, aluminium oxide, zirconia,titania, zeolite, and silica were used as an effective diffusion barrier [5].This study has been focused on the comparison between selective membranesfor H 2 separation obtained over modified PSS supports with an intermediate layer byELP and PVD-Magnetron Sputtering techniques. PSS supports purchased from MottMetallurgical have been initially cleaned by consecutive washing with HCl, NaOH andethanol solutions under ultrasonic irradiation at 333 K. After that, an intermetallicdiffusion barrier (mainly YSZ or silicalite-1) has been incorporated for avoiding the464