Analysis of interface structure during aluminum ion reduction using atomic force microscopy

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K04734
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 26060:Metals production and resources production-related
• Research Institution: Hokkaido University
• Principal Investigator: Ueda Mikito 北海道大学, 工学研究院, 教授 (00292053)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: イオン液体 / アルミニウム錯イオン / AFM測定

Outline of Final Research Achievements

In 1ethyl-3methylimidazolium chloride (EmImCl)-AlCl3 ionic liquid, the mechanism of aluminum deposition is reduced to aluminum when the Al complex ion receives an electron at the cathode. The distribution of Al complex ions in the neighborhood of the electrode was analyzed by force curve measurements using an atomic force microscope (AFM).
In the force curve measurement with potential applied, several steps were measured from the bulk to the electrode interface, which were considered to be ionic layers. The thickness of the ionic layer decreased as the potential became lower than the open circuit potential. This result suggests that the ionic layer composed of each ion is compressed during the reduction of Al complex ions, and the distance between the ionic layer and the interface becomes closer.

Free Research Field

電気化学

Academic Significance and Societal Importance of the Research Achievements

これまでAl錯イオンが還元されるメカニズムについては不明な部分が多いと考えられてきた。AFMのフォースカーブを測定してイオンの配列を測定する研究報告があったが、Al錯イオンを対象とするものは本研究が初めてであり、学術的に大きな意味がある研究であると考えられる。本研究における知見は、Al錯イオンに限るものではなく、アニオンから還元されるイオン種に関しての有益な情報になるものである。