First-principles investigation of hydrogen behavior in different oxides in ODS steels. (21st June 2019)

• Record Type: Journal Article
• Authors: Sun, Dan; Ding, Jianhua; Yang, Yaochun; Zhang, Pengbo; Zhao, Jijun
• Is Part Of: International journal of hydrogen energy. Volume 44:Number 31(2019)
• Page Start: 17105
• Page End: 17113
• Publication Date: 2019-06-21
• Subjects: Hydrogen -- Oxide crystals -- Migration; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2019.05.008
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: The energetics of single and multiple H atoms inside Y2 O3, Y2 Ti2 O7, Y2 TiO5, Y3 Al5 O12 and YAlO3 as well as the migration behavior of H atom have been investigated using first-principles calculations. Among these oxide matrixes, single H atom inside Y2 TiO5 is most energetically stable, followed by Y2 O3, Y2 Ti2 O7, Y3 Al5 O12 and YAlO3 . The migration barrier of H atom in Y2 O3 is lower than that in other oxide crystals. The formation energy and migration barrier of H atom in those oxide crystals are always higher than that in α-Fe. He atom is more stable than H atom inside oxide crystals, contrarily to the trend in α-Fe solid. Generally, in the cases of Hn (1 ≤ n ≤ 4) atoms inside oxide crystals, the formation energy of even-sized Hn cluster is lower than that of odd-sized Hn clusters, because two H atoms form a hydrogen molecule with strong H–H covalent bond. Highlights: H atom inside Y2 TiO5 is most stable, followed by Y2 O3, Y2 Ti2 O7, Y3 Al5 O12, and YAlO3 . H impurity is more difficult to diffuse in oxides than that in Fe matrix. Two H atoms form hydrogen molecule inside oxide crystals.