Mechanistic insight into the active centers of single/dual-atom Ni/Fe-based oxygen electrocatalysts

DOI: 10.1038/s41467-021-25811-0

Authors: Wenchao Wan (University of Zurich) , Yonggui Zhao (University of Zurich) , Shiqian Wei (Leshan Normal University) , Carlos A. Triana (University of Zurich) , Jingguo Li (University of Zurich) , Andrea Arcifa (Empa, Swiss Federal Institute for Materials Science and Technology) , Christopher Allen (Diamond Light Source; University of Oxford) , Rui Cao (Stanford Synchrotron Radiation Lightsource) , Greta R. Patzke (University of Zurich)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Nature Communications , VOL 12

State: Published (Approved)
Published: September 2021
Diamond Proposal Number(s): 16967

Abstract: Single-atom catalysts with maximum metal utilization efficiency show great potential for sustainable catalytic applications and fundamental mechanistic studies. We here provide a convenient molecular tailoring strategy based on graphitic carbon nitride as support for the rational design of single-site and dual-site single-atom catalysts. Catalysts with single Fe sites exhibit impressive oxygen reduction reaction activity with a half-wave potential of 0.89 V vs. RHE. We find that the single Ni sites are favorable to promote the key structural reconstruction into bridging Ni-O-Fe bonds in dual-site NiFe SAC. Meanwhile, the newly formed Ni-O-Fe bonds create spin channels for electron transfer, resulting in a significant improvement of the oxygen evolution reaction activity with an overpotential of 270 mV at 10 mA cm−2. We further reveal that the water oxidation reaction follows a dual-site pathway through the deprotonation of *OH at both Ni and Fe sites, leading to the formation of bridging O2 atop the Ni-O-Fe sites.

Journal Keywords: Catalysis; Catalytic mechanisms; Chemistry

Subject Areas: Chemistry, Energy

Diamond Offline Facilities: Electron Physical Sciences Imaging Centre (ePSIC)
Instruments: E02-JEM ARM 300CF

Added On: 27/09/2021 14:04

Documents:
s41467-021-25811-0.pdf

Discipline Tags:

Earth Sciences & Environment Sustainable Energy Systems Energy Climate Change Physical Chemistry Catalysis Chemistry

Technical Tags:

Microscopy Electron Microscopy (EM) Transmission Electron Microscopy (TEM)