Tailoring microenvironment for enhanced electrochemical CO2 reduction on ultrathin tin oxide derived nanosheets. (January 2023)

• Record Type: Journal Article
• Authors: Liu, Hai; Su, Yaqiong; Liu, Zhihui; Chuai, Hongyuan; Zhang, Sheng; Ma, Xinbin
• Is Part Of: Nano energy. Volume 105(2023)
• Publication Date: 2023-01
• Subjects: CO2 reduction -- SnO2 nanosheets -- Triple phase boundaries -- Gas diffusion electrode -- Microenvironment; Nanoscience -- Periodicals; Nanotechnology -- Periodicals; Nanostructured materials -- Periodicals; Power resources -- Technological innovations -- Periodicals; Nanoscience; Nanostructured materials; Nanotechnology; Power resources -- Technological innovations; Periodicals; 621.042
• DOI: 10.1016/j.nanoen.2022.108031
• Languages: English
• ISSNs: 2211-2855

Abstract

Abstract: Electrocatalytic CO2 reduction powered by renewable electricity has been considered as a promising approach for sustainable energy storage and chemicals production. Herein, ultrathin few-layer SnO2 nanosheets exposed with (001) facets were synthesized and exhibited a rather broad potential window (0.8 V) for selective CO2 conversion to formate. Both DFT calculations and operando spectroscopic characterizations were carried out to identify key intermediate *OCHO. Systematically tailoring microenvironment in the catalyst layer of gas diffusion electrode (GDE) indicate that both flexible Nafion and solid polytetrafluoroethylene (PTFE) nanoparticles are essential to create abundant and robust triple-phase boundaries (TPB) with more active sites, where CO2 and H2 O meet at nanosheet surface to output a high formate partial current density of 380 mA·cm -2 with the selectivity of 88.4%. Moreover, such novel Nafion/PTFE/SnO2 TPB porous structures above largely enhance the single-pass carbon efficiency up to 29.3% in 1 M KOH. This study implies that engineering TPB active sites is an effective approach to the design of advanced CO2 electrolyzers. Graphical Abstract: Flexible Nafion polymer and solid PTFE particles coated on tin oxide nanosheets are synergistic to construct effective TPB active sites, where CO2 molecules are coupled with electrons and protons to produce chemicals. ga1 Highlights: Engineering microenvironment is an effective approach to advanced CO2 electrolyzers. Both Nafion and polytetrafluoroethylene are essential to form triple-phase boundaries. Nafion/PTFE/SnO2 outputs a high formate partial current density of 380 mA·cm -2 .