Vanadium carbide coating as hydrogen permeation barrier: A DFT study |
| |
| Affiliation: | 1. International Research Center for Hydrogen Energy, Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka 819-0395, Japan;2. Research Center for Hydrogen Industrial Use and Storage (HYDROGENIUS), Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka 819-0395, Japan;3. International Institute for Carbon-Neutral Energy Research (WPI-I2CNER), Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka 819-0395, Japan;4. Kobe Material Testing Laboratory Co., Ltd., 47-13 Ni-jima, Harima-cho, Kako-gun, Hyogo 675-0155, Japan;1. Institute of Advanced Materials and Technology, University of Science and Technology Beijing, Beijing 100083, China;2. Chinese Academy of Engineering Physics, P.O. Box 919-71, Mianyang, Sichuan 621907, China;3. Department of Chemistry, Tsinghua University, Beijing 100084, China;1. Beijing Key Laboratory for Corrosion-Erosion and Surface Technology, Institute of Advanced Materials and Technology, University of Science and Technology Beijing, Beijing, 100083, China;2. Chinese Academy of Engineering Physics, P. O. Box 919-71, Mianyang, Sichuan, 621907, China |
| |
| Abstract: | Density functional calculations are used to investigate hydrogen (H) behaviors in vanadium carbide (VC). Molecular H2 dissociation, atomic H diffusion and penetration are analyzed using the transition state theory. H2 prefers to be close to the surface as physical adsorption, providing an environment conducive for further dissociation, and dissociates into atomic H adsorbed at the top C atom sites with co-adsorption state. The dissociation rate on the surface is mainly limited by the temperature-controlled activation energy barrier. The adsorptivity of atomic H by the surface tends to decrease as increasing of H coverage. For atomic H penetration through the surface, a significantly endothermic energy barrier and the low diffusion prefactor suggest that the main resistant effect of H permeation takes place at the surface. Energetic, vibrational, electronic consequences, and quantum effects on the H behaviors are discussed thoroughly. Our theoretical investigation indicates VC is a promising hydrogen permeation barrier. |
| |
| Keywords: | Vanadium carbide Hydrogen permeation barrier Hydrogen adsorption Hydrogen diffusion Hydrogen dissociation DFT |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
