Boosting formate production from CO2 electroreduction over gas diffusion electrode with accessible carbon mesopores. (10th January 2022)

• Record Type: Journal Article
• Authors: Han, Xiaohu; Wang, Qinian; Wu, Yongli; Wu, Chao
• Is Part Of: Electrochimica acta. Volume 402(2022)
• Publication Date: 2022-01-10
• Subjects: CO2 reduction -- Formate -- Gas diffusion electrode -- Mesoporous carbon -- Pore size distribution; Electrochemistry -- Periodicals; Electrochemistry, Industrial -- Periodicals; 541.37
• DOI: 10.1016/j.electacta.2021.139526
• Languages: English
• ISSNs: 0013-4686

Abstract

Highlight: Pore size distribution of carbon support is crucial for ERCF performance. Carbon support with 5–20 nm mesopores formed catalysts with abundant TPIs for ERCF. GDE with ordered mesoporous carbon support exhibited outstanding ERCF performance. Abstract: Electroreduction of CO2 to formate (ERCF) over a gas diffusion electrode with a Nafion-bonded carbon-supported Sn-based catalyst layer provides a promising approach for formate production. The ERCF performance is largely dependent on the carbon supports. However, the key influencing factors of the carbon supports for the ERCF performance have not yet been elucidated. We employed a variety of carbon supports with different pore structure features (activated carbon, acetylene black, and ordered mesoporous carbon) to explore the main factors influencing ERCF performance. The results showed that the pore size distribution was crucial for the ERCF performance. The ideal pore size was 5–20 nm. As it had the highest specific surface area within this pore size range among all the carbon supports examined, the ordered mesoporous carbon support obtained the highest ERCF performance (Faraday efficiency and current density for formate were 97.45 ± 2.97% and 80.12 ± 5.91 mA cm −2, respectively). Further analyses revealed that the increased ERCF performance was likely due to the large electroactive surface area, enhanced surface adsorption and activation capability of CO2, mesopore-induced proton transfer limitations for the hydrogen evolution reaction, and excellent charge transfer. This work is of significance for the further design of high-performance gas diffusion electrodes for the ERCF process. Graphical abstract: Image, graphical abstract