Curvature of NCNTs induced selectivity of CO2 electroreduction into CO

Abstract Nitrogen‐doped carbon nanotubes (NCNTs) are usually selective and robust electrocatalysts for CO 2 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 CO 2 RR performance. Herein, we investigated the CO 2 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 CO 2 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 CO 2 RR, thereby enhancing the catalytic activity of CO 2 electroreduction to CO.