Curvature of NCNTs induced selectivity of CO2 electroreduction into CO. Issue 2 (7th September 2022)

• Record Type: Journal Article
• Authors: Lv, Kuilin; Wan, Detian; Pan, Ruina; Suo, Weiqun; Zhu, Ying
• Is Part Of: Carbon neutralization. Volume 1:Issue 2(2022)
• Page Start: 189
• Page End: 197
• Publication Date: 2022-09-07
• Subjects: CO selectivity -- CO2 electroreduction -- curvature -- NCNTs; Carbon sequestration; Carbon dioxide mitigation; Carbon dioxide -- Environmental aspects; Clean energy; Periodicals; 363.73874
• DOI: 10.1002/cnl2.23
• Languages: English
• ISSNs: 2769-3325

Abstract

Abstract: Nitrogen‐doped carbon nanotubes (NCNTs) are usually selective and robust electrocatalysts for CO2 reduction to CO in aqueous media. However, the electronic property of NCNTs is strongly dependent on their curvature, the change of curvature has a great impact on the electrocatalytic performance. Therefore, it is highly desirable to clarify the curvature effect of NCNTs for CO2 RR performance. Herein, we investigated the CO2 RR performances of NCNTs with different curvatures, which were obtained by doping N into CNTs under high temperatures. And low curvature of l ‐NCNT‐1000 presented the highest CO FE (88.5%), which was much higher than that of the mid curvature of M‐NCNT‐1000 (71.1%) and the high curvature of S‐NCNT‐1000 (58%). According to density functional theory (DFT) calculations, the pyridine‐N site was considered a catalytic active site for CO2 RR regardless of the low, mid or high curvature structure. Moreover, the low curvature surface of NCNTs had a relatively large binding energy with the HOCO* intermediate that is the principal intermediate for the CO2 RR, thereby enhancing the catalytic activity of CO2 electroreduction to CO. Abstract : l ‐nitrogen‐doped carbon nanotubes (NCNT)‐1000 exhibited a superior CO2 RR performance with the highest CO FE of 88.5%, which was much higher than M‐NCNT‐1000 of 71.1% and S‐NCNT‐1000 of 58%. Moreover, DFT calculations indicated that the C‐N bond length (1.437A) of HOCO* and pyridine‐N on l ‐NCNT‐1000 with low curvature was shorter than that of S‐NCNT‐1000 with high curvature (1.456A) and M‐NCNT‐1000 with mid curvature (1.446A). The experiment and DFT simulation both showed that the diameter curvature of NCNT had an effect on selectivity and the CO FE for CO2 RR, which might provide a guide for the design of CNT‐based catalysts.