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Updated: Jan 21, 2026
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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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Local Structure and Coordination Define Adsorption in a Model Ir1 /Fe3 O4 Single-Atom Catalyst
Zdenek Jakub1, Jan Hulva1, Matthias Meier1,2
1Institute of Applied Physics, TU Wien, Wiedner Hauptstr. 8-10/134, 1040, Vienna, Austria.
Angewandte Chemie (International Ed. in English)
|July 25, 2019
Summary
Single-atom catalysts (SACs) show CO binds stronger at specific iridium sites on iron oxide supports. Iridium incorporation into the support deactivates these advanced catalysts.
Area of Science:
- Surface science
- Catalysis
- Coordination chemistry
Background:
- Single-atom catalysts (SACs) integrate homogeneous and heterogeneous catalysis principles.
- The electronic and structural environment of metal atoms in SACs dictates reactant adsorption and reactivity.
- Understanding the influence of support interactions on SACs is crucial for catalyst design.
Purpose of the Study:
- To investigate the CO binding behavior at distinct iridium single-atom sites on a Fe3O4(001) support.
- To elucidate the structural and electronic properties of iridium adatoms under varying thermal conditions.
- To identify key deactivation pathways for single-atom catalysts.
Main Methods:
- Atomically resolved scanning-probe microscopy
- X-ray photoelectron spectroscopy
- Temperature-programmed desorption
- Density Functional Theory (DFT) calculations
Main Results:
- Two- and five-fold coordinated Ir adatoms bind CO more strongly than metallic Ir.
- Iridium adatoms adopt square-planar Ir(I) and octahedral Ir(III) configurations.
- Ir incorporation into the Fe3O4 subsurface occurs at 450 K, leading to deactivation.
- Above 900 K, Ir adatoms form nanoparticles encapsulated by the iron oxide support.
Conclusions:
- SACs exhibit a direct correlation with coordination complex behavior.
- Subsurface incorporation represents a significant deactivation mechanism for SACs.
- Precise control over metal-support interactions is vital for maintaining SAC activity.
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