| Title |
Ab-initio Study of Hydrogen Permeation though Palladium Membrane |
| Authors |
차필령(Pil Ryung Cha); 김진유(Jin You Kim); 석현광(Hyun Kwang Seok); 김유찬(Yu Chan Kim) |
| ISSN |
1738-8228(ISSN), 2288-8241(eISSN) |
| Keywords |
hydrogen permeation; pd membrane; hydrogen embrittlement; penetration energy barrier; Ab inito study |
| Abstract |
Hydrogen permeation through dense palladium-based membranes has attracted the attention of many scientists largely due to their unmatched potential as hydrogen-selective membranes for membrane reactor applications. Although it is well known that the permeation mechanism of hydrogen through Pd involves various processes such as dissociative adsorption, transitions to and from the bulk Pd, diffusion within Pd, and recombinative desorption, it is still unclear which process mainly limits hydrogen permeation at a given temperature and hydrogen partial pressure. In this study, we report an all-electron density-functional theory study of hydrogen permeation through Pd membrane (using VASP code). Especially, we focus on the variation of the energy barrier of the penetration process from the surface to the bulk with hydrogen coverage, which means the large reduction of the fracture stress in the brittle crack propagation considering Griffith`s criterion. It is also found that the penetration energy barrier from the surface to the bulk largely decreases so that it almost vanishes at the coverage 1.25, which means that the penetration process cannot be the rate determining process. |