Pore-structure-enhanced electrochemical reduction of CO2 to formate on Sn-based double-layer catalysts

• Published in: Electrochemistry communications Vol. 128; p. 107056
• Main Authors: Xu, Keyi, Liu, Song, Cao, Ziqiang, Mao, Yuanxin, Mao, Qing
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-07-2021; Elsevier
• Subjects: CO2 electrochemical reduction reaction (CO2RR); CO2RR process simulation; Electrode kinetics analysis; Formate/Formic acid; Sn-based catalyst; Sn-based catalyst; CO2RR process simulation; Electrode kinetics analysis; Formate/Formic acid; CO2 electrochemical reduction reaction (CO2RR)
• ISSN: 1388-2481; 1873-1902
• DOI: 10.1016/j.elecom.2021.107056

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•Double-shell SnOx nanospheres with apertures of different sizes are synthesized.•A three-step reaction mechanism model is proposed for reduction of CO2RR to formate.•Appropriate geometrical design of Sn-based catalysts enables a high loading of CO2,ads in the CO2RR.
Sn-based materials can be used as electrocatalysts for the CO2 electroreduction reaction (CO2RR), preferentially producing formate. Although some Sn-based catalysts with a high faradaic efficiency for formate have been reported, the sensitivity of CO2RR activity to the catalyst structure remains elusive. Herein, a correlation between CO2RR activity and the geometric configuration of Sn-based catalysts was discovered using both double-shell SnOx nanospheres with apertures of different sizes, and CO2RR simulations using a three-step mechanism model. The kinetics analysis and simulation results suggest that a high loading of intermediate CO2,ads is the key to achieving high CO2RR performance with production of formate in the potential range −0.89 V ~ −1.26 V (vs. RHE). This understanding led to the design of double-shell SnOx nanospheres with enclosed apertures to increase the mesoporosity of the structure and hence its CO2 adsorption capability. Such a mechanism-guided approach to the design of catalysts not only enables a deep understanding of the CO2RR kinetics, but also sets a clear direction for the design of catalysts for scaled CO2RR applications.