Ultrathin palladium membranes prepared by a novel electric field assisted activation
Ultrathin palladium membranes prepared by a novel electric field assisted activation
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DOI：
10.1016/j.memsci.2010.12.015
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发表时间：
2011-03
期刊：
影响因子：
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通讯作者：
Samhun Yun;Joon-Ho Ko;S. Oyama
中科院分区：
文献类型：
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作者：
Samhun Yun;Joon-Ho Ko;S. Oyama
采用新型电场辅助活化技术，在中空纤维α-Al 2 O3载体上化学沉积Pd，制备了厚度为1μm的超薄Pd复合膜。新的活化方法将Pd前体和还原剂置于多孔基底的相对侧上，并使用电场使Pd离子迁移到外表面，在那里它们被还原以在狭窄的空间区域中形成高密度的种子。在733 K下150 h的稳定性测试中，所得膜显示出4.0-5.0×10− 6 molm −2s− 1 Pa − 1的高氢渗透率和3000-9000的稳定的H2/N2选择性。薄的、无缺陷的和坚固的Pd层的形成可以归因于在载体层上均匀分布的Pd种子以及在新的活化步骤中Pd种子在载体上的强锚定导致的Pd层和载体层之间的增强的结合。
Ultra-thin Pd composite membranes with a thickness of 1μm were prepared by a novel electric-field assisted activation technique followed by electroless deposition of Pd on a hollow-fiber α-alumina support. The novel activation method places Pd precursors and a reducing agent on opposite sides of a porous substrate and uses an electric field to cause migration of Pd ions to the outer surface where they are reduced to form seeds in high density in a narrow spatial region. The resulting membranes showed a high hydrogen permeance in the range of 4.0–5.0×10−6molm−2s−1Pa−1and stable H2/N2selectivity of 3000–9000 during stability tests for 150h at 733K with H2flow. The formation of the thin, defect-less and robust Pd layer can be ascribed to the evenly distributed Pd seeds on the support layer and the enhanced bonding between the Pd layer and the support layer resulting from the strong anchoring of the Pd seeds onto the support in the new activation step.