Affiliation:
1. Jiangsu Key Laboratory of New Power Batteries Jiangsu Collaborative Innovation Center of Biomedical Functional Materials School of Chemistry and Materials Science Nanjing Normal University Nanjing 210023 China
2. Advanced Institute for Materials Research (WPI‐AIMR) Tohoku University Sendai 980–8577 Japan
3. School of Chemistry and Chemical Engineering Southeast University Nanjing 210096 China
Abstract
AbstractEarth‐abundant Co X‐ides are emerging as promising catalysts for the electrocatalytic hydrogenation of quinoline (ECHQ), yet challenging due to the limited fundamental understanding of ECHQ mechanism on Co X‐ides. This work identifies the catalytic performance differences of Co X‐ides in ECHQ and provides significant insights into the catalytic mechanism of ECHQ. Among selected Co X‐ides, the Co3O4 presents the best ECHQ performance with a high conversion of 98.2% and 100% selectivity at ambient conditions. The Co3O4 sites present a higher proportion of 2‐coordinated hydrogen‐bonded water at the interface than other Co X‐ides at a low negative potential, which enhances the kinetics of subsequent water dissociation to produce H*. An ideal 1,4/2,3‐H* addition pathway on Co3O4 surface with a spontaneous desorption of 1,2,3,4‐tetrahydroquinoline is demonstrated through operando tracing and theoretical calculations. In comparison, the Co9S8 sites display the lowest ECHQ performance due to the high thermodynamic barrier in the H* formation step, which suppresses subsequent hydrogenation; while the ECHQ on Co(OH)F and CoP sites undergo the 1,2,3,4‐ and 4,3/1,2‐H* addition pathway respectively with the high desorption barriers and thus low conversion of quinoline. Moreover, the Co3O4 presents a wide substrate scope and allows excellent conversion of other quinoline derivatives and N‐heterocyclic substrates.