팔라듐 얇은 막의수소 투과에 대한 제일 원리 계산 (Ab-initio Study of Hydrogen permeation though Palladium Membrane)

서지정보

· 발행기관 : 대한금속·재료학회
· 수록지 정보 : 대한금속·재료학회지 / 46권 / 5호 / 296 ~ 303페이지
· 저자명 : 차필령, 김진유, 석현광, 김유찬

초록

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.

영어초록

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.

참고자료

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