期刊
JOURNAL OF FLUORINE CHEMISTRY
卷 211, 期 -, 页码 159-170出版社
ELSEVIER SCIENCE SA
DOI: 10.1016/j.jfluchem.2018.04.001
关键词
Graphite; Molten salt; FHR; MSR; Tritium
资金
- U.S. Department of Energy Nuclear Energy University Program [15-8352]
- Nuclear Regulatory Commission project [NRC-HQ-84-15-G-0046]
- NSF through the University of Wisconsin Materials Research Science and Engineering Center [DMR-1121288]
It is important for the development of advanced nuclear reactors to understand if the exposure to molten fluoride salts changes physical properties of graphite and its ability to absorb tritium. This paper demonstrated that the interaction between high purity nuclear grade graphite IG-110 and molten salt mixture 2LiF-BeF2 (FLiBe) at 700 degrees C for twelve hours in argon envimoment resulted in graphite fluorination and changes in graphite microstructure. XPS C1s spectra analysis shows an increase in F functionalization (from 3.5% to 9.0-19.3%), an increase in the sp(3)/sp(2) ratio (from 0.1496 to 0.1798), and F1s spectrum analysis confirms appearance of C-F bonds. Raman spectra show an increase in I-D/I-G ratio from 0.35 to 0.69 and an appearance of peak shoulders characteristic of C-F bond formation. GDMS depth analysis from the surface to 5 ism depth shows a higher depth penetration of F compared to that of Li and Be, indicative of surface salt reduction and bulk graphite fluorination. FLiBe reduction by graphite fluorination is not thermodynamically favorable, but certain carbon sites in the graphite are more reactive than the majority of carbon atoms in graphite. We argue that graphite fluorination occurred at these reactive sites, leading to the reduction of salt at the graphite surface. XRD and Raman confirmed microstructural changes. This indicates that the fluorination process may introduce new active sites as existing active sites are consumed, which could be advantageous for tritium chemisorption from FLiBe.
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