Sulfur-Dopant-Promoted Electroreduction of CO2 over Coordinatively Unsaturated Ni-N2 Moieties.
Chen JiaXin TanYong ZhaoWenhao RenYibing LiZhen SuSean C SmithChuan ZhaoPublished in: Angewandte Chemie (International ed. in English) (2021)
Atomically dispersed nickel-nitrogen-carbon (Ni-N-C) moieties are promising for efficient electrochemical CO2 -to-CO conversion. To improve the intrinsic electrocatalytic activity, it is essential but challenging to steer the coordination environment of Ni centers for promoting the CO formation kinetics. Here, we introduce alien sulfur atoms to tune the local electronic density of unsaturated NiN2 species. A coordinated structure evolution is detected and S vacancies are generated at high overpotentials, as confirmed by X-ray absorption spectroscopy. The sulfur dopants enhance CO selectivity and activity over normal unsaturated NiN2 structure, reaching a high CO Faradaic efficiency of 97 % and a large CO current density of 40.3 mA cm-2 in a H-cell at -0.8 V and -0.9 V (vs. RHE), respectively. DFT calculations reveal both doped S atoms and evolved S vacancies in the NiN2 coordination environment contribute to the reduced energy barriers for CO2 electroreduction to CO.
Keyphrases
- metal organic framework
- single cell
- density functional theory
- high resolution
- reduced graphene oxide
- gold nanoparticles
- cell therapy
- quantum dots
- genome wide
- molecular docking
- ionic liquid
- magnetic resonance imaging
- stem cells
- gene expression
- dna methylation
- mass spectrometry
- dual energy
- genetic diversity
- structural basis