Theoretical investigation and design of high density hydrogen storage materials using spill over process

2014 Fiscal Year Final Research Report

• Project/Area Number: 24560813
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Inorganic materials/Physical properties
• Research Institution: National Institute for Materials Science
• Principal Investigator: RYOJI Sahara 独立行政法人物質・材料研究機構, 構造材料ユニット, 主幹研究員 (30323075)
• Co-Investigator(Kenkyū-buntansha): KAWAZOE Yoshiyuki 未来科学技術共同研究センター, 教授 (30091672) ; MIZUSEKI Hiroshi 韓国科学技術研究院, 主幹研究員 (00271966) ; BELOSLUDOV Rodion 東北大学, 金属材料研究所, 准教授 (10396517)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: 水素貯蔵材料 / 第一原理計算 / 全電子混合基底法 / 解離 / 密度汎関数理論

Outline of Final Research Achievements

It has been reported that the hydrogen capacity of hydrogen storage materials is enhanced by adding a small amount of metal nanoparticles such as platinum and nickel. The phenomenon is explained as a hydrogen spill-over process, where hydrogen molecules are dissociated on the surface of nanoparticles and then hydrogen atoms diffuse on the surface of the storage materials and are chemisorbed.
In the present study, we focus our target on the initial stage, i.e., a dissociation pathway of a hydrogen molecule on a metal nanoparticle. We performed an Ehrenfest dynamics simulation on the basis of time-dependent density functional theory. In the presence of a nickel dimer, hydrogen dissociation can occur when just a single electron is excited by at least 0.10 eV to the non-bonding LUMO level. The subsequent separation of the hydrogen atoms occurs with level crossings that temporarily move the excited electron back into the new HOMO level.

Free Research Field

計算材料科学