학술논문
Improved the H2 S corrosion resistance for Nb30 Hf35 Co35 alloy by modifying surface catalytic layer
Document Type
Original Paper
Author
Source
Journal of Materials Science. 58(46):17664-17674
Subject
Language
English
ISSN
0022-2461
1573-4803
1573-4803
Abstract
This work prepared a novel PdCu-coated Nb30 Hf35 Co35 self-supported membrane by regulating the composition of the outermost catalytic film, and we report its performance in gas mixtures containing H2 S for the first time. The results show that this membrane not only has higher pure H2 permeation performance but also excellent H2 S resistance. At 120 ppm H2 S in the feed, the permeability of this membrane is 1.6 × 10–8 mol H2 m−1 s−1 Pa−0.5 at 673 K, which is 3.2 (8.1) times that of the Pd-coated counterpart (and pure Pd). Furthermore, this membrane can be stable for at least 240 h. By first-principles calculations, our results also showed that alloying Pd with Cu inhibits the formation of palladium sulphide (e.g., Pd4 S), thus providing more activating active sites for hydrogen adsorption and dissociation. This could be the main reason for the improvement of hydrogen permeability of PdCu-coated composite membranes in an H2 S atmosphere. This study suggests that appropriately adjusting the type or composition of the catalytic layer is an effective method to alleviate membrane H2 S poisoning, an aspect not widely studied in 5B group alloys.