Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5147756 | International Journal of Hydrogen Energy | 2017 | 10 Pages |
Abstract
In this study, we present an intermetallic diffusion barrier coating using a newly developed blowing coating method for a thermally stable Pd-based composite membrane on porous stainless steel (PSS). A tubular PSS sample with 1/2 inch (12.7 mm) in diameter and 450 mm in length was used for the support. The support was welded with a stainless-steel cap and a 450-mm-long stainless-steel tube for each end. Before the diffusion barrier coating, the large-sized entrance pores were gradually blocked with sub-micron (â¼500 nm) and nano (50-80 nm) yttria stabilized zirconia (YSZ). 8YSZ, i.e., 8wt.% YSZ, was used for the interdiffusion barrier material and dispersed on the surface of the pre-treated PSS using the blowing coating method. The blowing coating method has 4 steps: (i) spraying the 17 wt. % 8YSZ paste on the surface of the PSS tube, (ii) blowing the paste using compressed air, (iii) drying at room temperature, and (iv) heat treatment at 923 K for 2 h in air. Steps (i) and (ii) were repeated 3 times to have a â¼240 nm thick 8YSZ layer. A thin palladium layer (â¼3 μm) was deposited on the pre-treated PSS using electroless plating, and the membrane stability was tested at 673-773 K for â¼Â 200 h. A hydrogen permeation flux of 9.86 Ã 10â2 mol mâ2 sâ1 and an H2/N2 selectivity of 595 were obtained at 773 K and a transmembrane pressure difference of 20 kPa. The surface and cross-sectional SEM/EDX analysis confirmed that the 8YSZ layer sufficiently prevented the interdiffusion between Pd and PSS elements, such as Fe, Cr and Ni.
Related Topics
Physical Sciences and Engineering
Chemistry
Electrochemistry
Authors
Jae-Yun Han, Chang-Hyun Kim, Hankwon Lim, Kwan-Young Lee, Shin-Kun Ryi,