期刊
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
卷 42, 期 34, 页码 21832-21840出版社
PERGAMON-ELSEVIER SCIENCE LTD
DOI: 10.1016/j.ijhydene.2017.07.072
关键词
Intermetallic compounds; Hydrogen-storage materials; CeNi5-xAlx alloys; Size effects; Site preference; Hydrogenation of propyne
资金
- Ministry of Education, Culture, Sports, Science and Technology (MEXT) of Japan [24656365]
- Dynamic Alliance for Open Innovation Bridging Human, Environment and Materials
- Grants-in-Aid for Scientific Research [24656365, 17K14327] Funding Source: KAKEN
The hydrogenation capacities of CeNi5-xAlx (x = 0, 0.75, 1.0, 1.25, 1.5 and 1.75) alloys were assessed. In contrast to LaNis-based alloys, the addition of Al to CeNis enables hydrogen absorption by creating larger interstitial sites as the result of an expanded lattice. Structure analyses indicate that each of these alloys maintained a CeNi5 (CaCu5-type) structure in which Al atoms exclusively occupied Ni 3g sites. Among these specimens, CeNi4Al absorbed the greatest proportion of hydrogen atoms, decreasing its c/a ratio from 0.826 to 0.802 upon the formation of CeNi4AlH4.3. This drastic decrease in the c/a ratio is attributed to an anisotropic lattice expansion along the a-axis, as verified by in situ X-ray diffraction under H-2. The enhanced hydrogen absorption of these alloys is thought to be associated with the preferential situation of hydrogen atoms at interstitial sites located at the centers of octagons as well as a charge transition of Ce ions upon hydrogenation. It is verified that CeNi4Al after hydrogenation shows high catalytic activity toward propyne hydrogenation: 100% conversion of propyne even at room temperature. (C) 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据