Solvation Structure and Dynamics in Elementary Reaction of CO2 Electrochemical Reduction

2020 Fiscal Year Final Research Report

• Project/Area Number: 18K05039
• 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: Saga University
• Principal Investigator: Umeki Tatsuya 佐賀大学, 理工学部, 准教授 (00384735)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: 炭酸水素イオン / ギ酸 / NMR / pH

Outline of Final Research Achievements

An understanding of the solvation structure and molecular/ion dynamics for aqueous solutions of CO2 reduction products at the molecular level is important for improving the efficiency of CO2 electrochemical reduction. In this study, we focused on formic acid as a CO2 reduction product. We measured the longitudinal relaxation times and self-diffusion coefficients of formate ion in aqueous solutions with and without sodium hydrogen carbonate by means of NMR method. The rotational correlation times of formate ion in aqueous solutions with and without sodium hydrogen carbonate were determined. We discussed the ion dynamics of formate ion in aqueous solutions of sodium hydrogen carbonate. Moreover, we measured pH, density, electrical conductivity, and viscosity of aqueous solution of formic acid with and without sodium formate, and then discussed the acid dissociation equilibrium in aqueous solutions.

Free Research Field

溶液分析化学

Academic Significance and Societal Importance of the Research Achievements

CO2電気化学還元は，CO2を物質変換する方法の一つであり，水溶液中におけるギ酸イオンの溶媒和構造やダイナミクスなどの溶液構造に関する知見やギ酸イオンとギ酸分子の酸解離平衡に関する知見は，CO2からギ酸を生成する電気化学還元の高効率化や高速化において，重要な知見になるものと考えられる．