Dynamics of hydrogen at surfaces in space-time limit

2020 Fiscal Year Final Research Report

• Project/Area Number: 18K05030
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 32010:Fundamental physical chemistry-related
• Research Institution: Kyoto University
• Principal Investigator: Okuyama Hiroshi 京都大学, 理学研究科, 准教授 (60312253)
• Co-Investigator(Kenkyū-buntansha): 渡邊 一也 京都大学, 理学研究科, 教授 (30300718)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: 水素 / 走査トンネル顕微鏡

Outline of Final Research Achievements

O-H flip motion was induced for a hydroxyl dimer on Cu (110) by irradiating it with a pulse laser. The reaction rate of the flip motion was measured as a function of the delay time of the pulses, where the damping behavior of about 400 fs was observed. This suggests that the flip motion proceeds in the multi-photon process and that the lifetime of the vibration excited state is about 400 fs. In addition, the photoelimination reaction of nitric oxide was observed by STM, and it was clarified that it proceeds in a non-adiabatic process and that the reaction rate strongly depends on the molecular environment on the surface.

Free Research Field

表面化学

Academic Significance and Societal Importance of the Research Achievements

固体表面における水素原子やプロトンの反応，運動を解明することは，燃料電池や触媒による水素化反応のメカニズムを理解する手掛かりとなる．本研究では燃料電池で重要な表面水酸基(OH)の超高速励起ダイナミクス計測を行い，光によって水酸基が反応する様子を捉えることで，その励起状態が400 fsで失活することを明らかにした。電極表面で起こる水素のエネルギー失活は電池の性能に直結するため，より性能の高い電池を開発する上で重要な知見になると考えられる。