Buffering electrolyte alkalinity for highly selective and energy-efficient transformation of CO2 to CO

Autor: Liangyou Hu, Bowen Deng, Zhengshan Yang, Dihua Wang
Jazyk: angličtina
Rok vydání: 2020
Předmět:
Zdroj: Electrochemistry Communications, Vol 121, Iss , Pp 106864- (2020)
Druh dokumentu: article
ISSN: 1388-2481
DOI: 10.1016/j.elecom.2020.106864
Popis: Electroreduction of CO2 to value-added products is a promising strategy for renewable energy storage using a carbon-neutral cycle. In this work, we report a feasible electrochemical approach to achieving highly efficient CO2-to-CO conversion by buffering electrolyte alkalinity in borate-containing molten salts, where borates acting as a buffer system can regulate the concentration of sequentially released O2− (defined as a base) in the electrolyte, changing the thermodynamic reaction pathway of the CO2 reduction reaction (CO2RR). Taking the CO2RR in LiBO2-containing molten LiCl–Li2CO3 as an example, CO is more preferentially generated in this medium compared with a borate-free electrolyte (where mainly carbon products are produced). The faradaic efficiency for producing CO was over 90% at a current density of 100 mA/cm2, with a very low energy consumption of 1.06 kWh/Nm3-CO at a relatively low temperature (650 °C). This facile and energy-efficient strategy suggests an approach to steering the CO2RR toward desired products with improved energy efficiency.
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