Temperature dependent electrochemical reduction of CO2 at temperature controllable-rotating disk electrode modified with bismuth film

• Published in: Electrochimica acta 2023-09, Vol.461, p.142627, Article 142627
• Main Authors: Qin, Su-Fang, Yang, Sen, Zhao, Liu-Chuang, Xie, Yuan-Jiang, Wang, Yi, You, Le-Xing, Li, Ju, Sun, Jian-Jun
• Format: Article
• Language: English
• Subjects: Apparent activation energy; Electrochemical CO2 reduction; Faradic efficiency; Kinetics; Temperature controllable-rotating disk electrode
• ISSN: 0013-4686
• DOI: 10.1016/j.electacta.2023.142627

•A temperature controllable-rotating disk electrode (TCRDE) is fabricated.•The solubility of CO2 can keep constant when temperature change by using TCRDE.•Ea, app of CO2 reduction at a Bi electrode is firstly reported as 46 kJ⋅mol−1.•The values of k0 increase by 170% with Ts elevating from 25 °C to 65 °C. Temperature is an important parameter regulating the selectivity and reaction activity of electrochemical CO2 reduction reaction (CO2RR). However, it is challenging to evaluate the effect of temperature on electrochemical CO2RR without changing the CO2 solubility in water. Herein, a glassy carbon temperature controllable-rotating disk electrode (TCRDE-GC) was fabricated and the heat transfer was studied using temperature transfer coefficient (αT). As the only parameter required to calibrate the electrode surface temperature (Ts), αT was found to be correlated with the square root of the angular velocity of rotation. A bismuth film modified TCRDE was used to investigate Ts function on electrochemical CO2RR in the CO2-saturated K2SO4 solution where the CO2 solubility did not change. The apparent activation energy of electrochemical CO2RR was firstly reported as 46 kJ⋅mol−1. Electrochemical and ion chromatography results suggested that increasing Ts could accelerate the reaction rate of electrochemical CO2RR (increased by 170% with Ts increasing from 25 to 65 °C) and enhance product yield (increased by 40% with Ts increasing from 25 to 45 °C), whereas, could not change the type of main products. There was no regular effect of Ts on Faradic efficiency of HCOO− production. This work provides a new method to study the effect of electrode surface temperature on the CO2RR at the electrode / solution interface and it may be extended to other similar systems for further in-depth investigation. A temperature-controlled rotating disk electrode (TCRDE) is fabricated. TCRDE modified with bismuth film is used to evaluate the temperature effect on electrochemical CO2RR in CO2-saturated K2SO4 solution where the CO2 solubility does not change. It may be helpful and universal to understand electrochemical reaction kinetics of CO2RR and can be extended to other similar systems for further in-depth investigation. [Display omitted]