Study of MgH2 in bulk Mg formation mechanism

2020 Fiscal Year Final Research Report

• Project/Area Number: 19K15278
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 26010:Metallic material properties-related
• Research Institution: Kansai University
• Principal Investigator: KONDO Ryota 関西大学, 化学生命工学部, 准教授 (60709088)
• Project Period (FY): 2019-04-01 – 2021-03-31
• Keywords: Mg / 水素 / 化学反応 / 触媒

Outline of Final Research Achievements

Mg shows a high hydrogen storage amount of 7.6 mass%, however formation rate of MgH2 is very slow. Conventional approaches were proposed such as adding a catalyst or sub-micronization of Mg powder. Careful observation of the hydrogenated microstructure of Mg revealed that in addition to MgH2 (sur) produced on the surface layer, MgH2 (int) was also produced inside unreacted Mg It was found that the growth of this MgH2 (int) affected the Mg matrix, and the nucleation frequency was affected by the hydrogen supply and defects.

Free Research Field

水素貯蔵材料

Academic Significance and Societal Importance of the Research Achievements

水素ガス-Mgの気-固相反応で生成すると考えられていたMgH2は、Mg中へ固溶した水素とMgの固-固相反応によってもMgH2が生成することが明らかとなった。多くの場合の反応は気液、固液界面を議論とするため、気相や液相の圧力を無視する場合が多いが、固相内反応で反応が進むため、反応場となるMgの影響が議論されることになる。固相内での濡れを考える必要があり、界面反応の新たな分析に役立つものと期待される。