Preparation of a Pd membrane on a WO3 modified Porous Stainless Steel for hydrogen separation

A novel approach for the preparation of highly stable Pd membrane on macroporous α-Al2O3 tube

“…It is made of sintered ␣-Al 2 O 3 particles of irregular size and shape giving the support a broad pore size distribution and a rough surface. Inspection revealed that pores as large as 10 m are not uncommon in this support as in the case of porous stainless steel [20,39].…”

“…This is particularly true for palladium supported on stainless steel, wherein the diffusion barrier was shown to be important for mitigating contamination of the Pd by components of the support. Porous metal and refractory oxides including Al 2 O 3 [33,34], CeO 2 [35], SiO 2 [36], TiO 2 [37], ZrO 2 [38] and WO 3 [39] have been investigated, but long-term performance data are seldom included. Zahedia and coworkers [39] reported palladium membrane supported on WO 3 modified stainless steel support provides stable hydrogen permeance during 20 days of continuous run.…”

Hydrogen Permeation through Porous Stainless Steel for Palladium based Composite Porous Membranes

“…The common method to modify the surface of the PSS is to use an intermediate layer capable of reducing the surface pore size whilst, simultaneously serving as an inter-diffusion barrier. Various intermediate layers such as Al 2 O 3 (alumina) [16,30], TiN [36] , ZrO 2 [31] , Ni [14] , W/WO 3 [37,38] , and Yttria-Stabilised Zirconia (YSZ) [12,39] have been employed. In addition, Ma et al [40] investigated the formation of an in-situ oxide layer on the surface of PSS as an inter-diffusion barrier.…”

Preparation of palladium membrane on Pd/silicalite-1 zeolite particles modified macroporous alumina substrate for hydrogen separation

“…Mardilovich and co-workers confirmed that the larger pore size of the support, the thicker of the palladium film is required to obtain dense membrane [17]. A proper solution is to modify the coarse surface of the porous substrates by some intermediate materials, including WO 3 [18], Al 2 O 3 [19,20], ZrO 2 [21], CeO 2 [22], NaA zeolite [23] and pencil power [13]. The intermediate layer not only improved the pore size of the substrate and its surface roughness, but also behaved as a diffusion barrier to protect the membrane from the support contaminants.…”