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Synthesis and Performance Characterizations of Transition Metal Single Atom Catalyst for Electrochemical CO2 Reduction
Published on: April 10, 2018
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Nickel Incorporation into Fresh Iron Sulfide Precipitates Modulates Selectivity in Nitrite, Carbon Dioxide, and
C Felipe Garibello1,2, Shawn Erin McGlynn2,3,4, Yamei Li2
1Department of Chemistry and Biotechnology, School of Science, Computing and Engineering Technologies, Swinburne University of Technology, Victoria 3122, Australia.
Inorganic Chemistry
|November 13, 2025
Summary
Coprecipitated nickel-iron sulfides show varying catalytic abilities for reducing carbon dioxide, nitrite, and protons. Their structure and composition dictate reactivity, mirroring biological metal use in early metabolism.
Area of Science:
- Geochemistry
- Biogeochemistry
- Prebiotic Chemistry
Background:
- Nickel and iron sulfides are vital in Earth's biogeochemical cycles.
- These metals are crucial in metalloenzyme active sites and proposed prebiotic catalysts.
Purpose of the Study:
- Investigate how coprecipitated Ni-Fe sulfides' catalytic abilities for CO2, NO2-, and proton reduction vary.
- Relate these catalytic differences to structural and compositional properties.
Main Methods:
- Synthesized sulfides via direct precipitation.
- Characterized samples using X-ray absorption spectroscopy (XAS) at Ni and Fe K-edges.
Main Results:
- Low Ni:Fe ratios formed Ni-substituted mackinawite ([Ni_nFe_m]Sx).
- High Ni content favored NiS2-like structures, suppressing FeS.
- Increased Ni content enhanced CO2 and proton reduction, and NO2- reduction.
- Fe-rich samples favored NO2- reduction but suppressed H2 evolution.
Conclusions:
- Observed reactivity trends suggest distinct reduction mechanisms for protons, CO2, and nitrite.
- Reactivity mirrors biological metal utilization, highlighting Ni-Fe sulfides as potential protoenzymatic catalysts in early metabolism.
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