A two-step electroless plating method for Pd composite membranes with enhanced hydrogen selectivity and superior high-temperature stability. Issue 5 (October 2022)

• Record Type: Journal Article
• Authors: Yang, Yuxin; Li, Xinzhong; Liang, Xiao; Chen, Ruirun; Guo, Jingjie; Fu, Hengzhi; Liu, Dongmei
• Is Part Of: Journal of environmental chemical engineering. Volume 10:Issue 5(2022)
• Publication Date: 2022-10
• Subjects: Hydrogen separation -- Pd membrane -- Electroless plating -- Heat treatment; Chemical engineering -- Environmental aspects -- Periodicals; Environmental engineering -- Periodicals; Chemical engineering -- Environmental aspects; Environmental engineering; Periodicals; 660.0286
• DOI: 10.1016/j.jece.2022.108477
• Languages: English
• ISSNs: 2213-2929

Abstract

Abstract: Thin Pd membranes were deposited on modified porous YSZ-Al2 O3 tubes using a two-step electroless plating (ELP) method for hydrogen separation and purification. The two-step ELP method consists of the first ELP, the heat treatment and the second ELP. The effects of heat treatment conditions in the two-step ELP on the hydrogen selectivity and high-temperature stability of Pd composite membranes were investigated. Pd membranes prepared by different processes exhibit different microstructure and permeation performance. The result shows that Pd membranes prepared by the two-step ELP method and the high-temperature heat treatment (923 K) above the Tamman temperature of pure Pd (> 913 K) between two ELP exhibit the best performance, which is mainly attributed to the two-layer membrane structure and the small Pd crystals in the membranes. The Pd membrane with a thickness of ~6.5 µm prepared via above process exhibited a high and stable hydrogen permeation flux (~0.359 mol H2 m −2 s −1 ) and a significantly high H2 /N2 selectivity (~12, 413) for a long-term permeation of 100 h at 873 K under a pressure difference of 0.1 MPa. Highlights: Thin (~6.5 µm) Pd membranes were prepared using a two-step ELP method. Heat treatment conditions in two-step ELP affect the performance of Pd membranes. The high-temperature heat treatment (923 K) enhances the stability of Pd membranes. The Pd membranes exhibit the two-layer structure and small crystals. H2 flux was ~0.359 mol H2 m −2 s −1 and selectivity was ~12, 413 at 873 K and 0.1 MPa.