Nickel Single Atom Density-Dependent CO 2 Efficient Electroreduction

• Published in: Small (Weinheim an der Bergstrasse, Germany) Vol. 20; no. 16; p. e2308080
• Main Authors: Zhang, Fengwei, Zhang, Han, Jia, Zhenhe, Chen, Shuai, Li, Siming, Li, Jijie, Zan, Wen-Yan, Wang, Qiang, Li, Yawei
• Format: Journal Article
• Language: English
• Published: Germany 01-04-2024
• Subjects: CO2 electroreduction; NiN4 active site; precise regulation; N‐doped graphene‐like carbon; single atom density
• ISSN: 1613-6810; 1613-6829
• DOI: 10.1002/smll.202308080

The transition metal-nitrogen-carbon (M─N─C) with MNx sites has shown great potential in CO
electroreduction (CO
RR) for producing high value-added C
products. However, a comprehensive and profound understanding of the intrinsic relationship between the density of metal single atoms and the CO
RR performance is still lacking. Herein, a series of Ni single-atom catalysts is deliberately designed and prepared, anchored on layered N-doped graphene-like carbon (x Ni
@NG-900, where x represents the Ni loading, 900 refers to the temperature). By modulating the precursor, the density of Ni single atoms (D
) can be finely tuned from 0.01 to 1.19 atoms nm
. The CO
RR results demonstrate that the CO faradaic efficiency (FE
) predominantly increases from 13.4% to 96.2% as the D
increased from 0 to 0.068 atoms nm
. Then the FE
showed a slow increase from 96.2% to 98.2% at -0.82 V versus reversible hydrogen electrode (RHE) when D
increased from 0.068 to 1.19 atoms nm
. The theoretical calculations are in good agreement with experimental results, indicating a trade-off relationship between D
and CO
RR performance. These findings reveal the crucial role of the density of Ni single atoms in determining the CO
RR performance of M─N─C catalysts.