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In-situ generated hydroxides realize near-unity CO selectivity for electrochemical CO2 reduction.
- Source :
-
Chemical Engineering Journal . Apr2022:Part 3, Vol. 433, pN.PAG-N.PAG. 1p. - Publication Year :
- 2022
-
Abstract
- [Display omitted] • OH− ions were created by the in-situ synthesis of CdCO 3 (i-CdCO 3) on the electrode. • The i-CdCO 3 delivers near-unity selectivity for the electroreduction of CO 2 to CO. • An ultrahigh mass activity of 165.1 mA mg−1 was achieved on i-CdCO 3 at − 1.26 V. • The superior CO selectivity is due to an increased local pH which inhibits HER. Electrochemical reduction of CO 2 to CO is an attractive approach for the sustainable carbon cycle. However, the activity and selectivity of the CO 2 reduction reaction (CO 2 RR) are often limited by the competitive hydrogen evolution reaction (HER) in aqueous media. In this work, in-situ generated hydroxides were introduced by the synthesis of rhombohedral CdCO 3 crystals (i-CdCO 3) under electrochemical CO 2 RR conditions. The generated hydroxides contribute to an increased local pH at the electrode/electrolyte interface, thereby effectively inhibiting HER. As a result, the obtained i-CdCO 3 exhibits remarkably higher CO Faradaic efficiency (over 90%) in a broad potential range, where a near 100% selectivity is achieved, as compared to a pre-synthesized CdCO 3 with similar morphology. Moreover, i-CdCO 3 delivers a large current density of − 24.8 mA mg−1 at − 1.26 V, together with a good stability of 36 h with negligible degradation, further demonstrating its superiority for efficient CO 2 RR. This study proposes a promising design strategy to boost the selectivity of CO 2 RR systems through in-situ producing hydroxides near the electrode to suppress the unfavorable HER. [ABSTRACT FROM AUTHOR]
- Subjects :
- *ELECTROLYTIC reduction
*HYDROGEN evolution reactions
*CARBON dioxide
*CARBON cycle
Subjects
Details
- Language :
- English
- ISSN :
- 13858947
- Volume :
- 433
- Database :
- Academic Search Index
- Journal :
- Chemical Engineering Journal
- Publication Type :
- Academic Journal
- Accession number :
- 155102472
- Full Text :
- https://doi.org/10.1016/j.cej.2021.133785