Grain Boundary Segregation in Pd-Cu-Ag Alloys for High Permeability Hydrogen Separation Membranes
Dense metal membranes that are based on palladium (Pd) are promising for hydrogen separation and production due to their high selectivity and permeability. Optimization of alloy composition has normally focused on bulk properties, but there is growing evidence that grain boundaries (GBs) play a cruc...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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MDPI AG
2018-09-01
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| Series: | Membranes |
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| Online Access: | http://www.mdpi.com/2077-0375/8/3/81 |
| _version_ | 1797721030544850944 |
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| author | Ole Martin Løvvik Dongdong Zhao Yanjun Li Rune Bredesen Thijs Peters |
| author_facet | Ole Martin Løvvik Dongdong Zhao Yanjun Li Rune Bredesen Thijs Peters |
| author_sort | Ole Martin Løvvik |
| collection | DOAJ |
| description | Dense metal membranes that are based on palladium (Pd) are promising for hydrogen separation and production due to their high selectivity and permeability. Optimization of alloy composition has normally focused on bulk properties, but there is growing evidence that grain boundaries (GBs) play a crucial role in the overall performance of membranes. The present study provides parameters and analyses of GBs in the ternary Pd-Ag-Cu system, based on first-principles electronic structure calculations. The segregation tendency of Cu, Ag, and vacancies towards 12 different coherent ∑ GBs in Pd was quantified using three different procedures for relaxation of supercell lattice constants, representing the outer bounds of infinitely elastic and stiff lattice around the GBs. This demonstrated a clear linear correlation between the excess volume and the GB energy when volume relaxation was allowed for. The point defects were attracted by most of the GBs that were investigated. Realistic atomic-scale models of binary Pd-Cu and ternary Pd-Cu-Ag alloys were created for the ∑5(210) boundary, in which the strong GB segregation tendency was affirmed. This is a starting point for more targeted engineering of alloys and grain structure in dense metal membranes and related systems. |
| first_indexed | 2024-03-12T09:28:00Z |
| format | Article |
| id | doaj.art-26ad71fb8eae47a48c1f92c1843961b1 |
| institution | Directory Open Access Journal |
| issn | 2077-0375 |
| language | English |
| last_indexed | 2024-03-12T09:28:00Z |
| publishDate | 2018-09-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Membranes |
| spelling | doaj.art-26ad71fb8eae47a48c1f92c1843961b12023-09-02T14:00:41ZengMDPI AGMembranes2077-03752018-09-01838110.3390/membranes8030081membranes8030081Grain Boundary Segregation in Pd-Cu-Ag Alloys for High Permeability Hydrogen Separation MembranesOle Martin Løvvik0Dongdong Zhao1Yanjun Li2Rune Bredesen3Thijs Peters4SINTEF Industry, N-0314 Oslo, NorwayDepartment of Materials Science and Engineering, Norwegian University of Science and Technology (NTNU), 7491 Trondheim, NorwayDepartment of Materials Science and Engineering, Norwegian University of Science and Technology (NTNU), 7491 Trondheim, NorwaySINTEF Industry, N-0314 Oslo, NorwaySINTEF Industry, N-0314 Oslo, NorwayDense metal membranes that are based on palladium (Pd) are promising for hydrogen separation and production due to their high selectivity and permeability. Optimization of alloy composition has normally focused on bulk properties, but there is growing evidence that grain boundaries (GBs) play a crucial role in the overall performance of membranes. The present study provides parameters and analyses of GBs in the ternary Pd-Ag-Cu system, based on first-principles electronic structure calculations. The segregation tendency of Cu, Ag, and vacancies towards 12 different coherent ∑ GBs in Pd was quantified using three different procedures for relaxation of supercell lattice constants, representing the outer bounds of infinitely elastic and stiff lattice around the GBs. This demonstrated a clear linear correlation between the excess volume and the GB energy when volume relaxation was allowed for. The point defects were attracted by most of the GBs that were investigated. Realistic atomic-scale models of binary Pd-Cu and ternary Pd-Cu-Ag alloys were created for the ∑5(210) boundary, in which the strong GB segregation tendency was affirmed. This is a starting point for more targeted engineering of alloys and grain structure in dense metal membranes and related systems.http://www.mdpi.com/2077-0375/8/3/81membranehydrogenpalladium alloygrain boundary |
| spellingShingle | Ole Martin Løvvik Dongdong Zhao Yanjun Li Rune Bredesen Thijs Peters Grain Boundary Segregation in Pd-Cu-Ag Alloys for High Permeability Hydrogen Separation Membranes Membranes membrane hydrogen palladium alloy grain boundary |
| title | Grain Boundary Segregation in Pd-Cu-Ag Alloys for High Permeability Hydrogen Separation Membranes |
| title_full | Grain Boundary Segregation in Pd-Cu-Ag Alloys for High Permeability Hydrogen Separation Membranes |
| title_fullStr | Grain Boundary Segregation in Pd-Cu-Ag Alloys for High Permeability Hydrogen Separation Membranes |
| title_full_unstemmed | Grain Boundary Segregation in Pd-Cu-Ag Alloys for High Permeability Hydrogen Separation Membranes |
| title_short | Grain Boundary Segregation in Pd-Cu-Ag Alloys for High Permeability Hydrogen Separation Membranes |
| title_sort | grain boundary segregation in pd cu ag alloys for high permeability hydrogen separation membranes |
| topic | membrane hydrogen palladium alloy grain boundary |
| url | http://www.mdpi.com/2077-0375/8/3/81 |
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