Coverage-Dependent N2 Adsorption and Its Modification of Iron Surfaces Structures

详细信息    查看全文

• 作者：Tao Wang ; Xinxin Tian ; Yong Yang ; Yong-Wang Li ; Jianguo Wang ; Matthias Beller ; Haijun Jiao
• 刊名：Journal of Physical Chemistry C
• 出版年：2016
• 出版时间：February 11, 2016
• 年：2016
• 卷：120
• 期：5
• 页码：2846-2854
• 全文大小：684K
• ISSN：1932-7455

文摘

Spin-polarized density functional theory calculations were performed to investigate N₂ dissociative adsorption on iron (100), (110), (111), (210), (211), (310), and (321) surfaces. An ordered c(2 × 2) structure was found on Fe(100) at 0.5 monolayer coverage, which is in excellent agreement with the experiment; and a c(4 × 2) ordered structure is also found at 0.75 monolayer saturation coverage. Strong surface reconstruction is found on Fe(110) upon nitrogen adsorption, where the densely packed (110) is reconstructed into (100)-alike. Under the consideration of temperature and N₂ partial pressure, the estimated N₂ desorption temperature on Fe(100) at 925 K agrees with the experimentally detected 920–950 K. In addition, N₂ pretreatment results in Fe(100) to be mostly exposed, while that of H₂ pretreatment favors Fe(110). Further direct comparison of N₂ and H₂ adsorptions has been made to show their differences and similarities.