Hydrogen Activation via Dihydride Formation on a Rh1/Fe3O4(001) Single-Atom Catalyst
Chunlei Wang1, Panukorn Sombut1, Lena Puntscher1
1Institute of Applied Physics, TU Wien, Vienna, Austria.
Angewandte Chemie (International Ed. in English)
|February 19, 2026
Summary
Isolated rhodium atoms on iron oxide activate hydrogen via a dihydride intermediate, mimicking homogeneous catalysts and bridging homogeneous and heterogeneous catalysis mechanisms without hydrogen spillover.
Area of Science:
- Heterogeneous catalysis
- Surface science
- Single-atom catalysis
Background:
- Hydrogen activation is crucial for hydrogenation reactions.
- Heterogeneous catalysis typically involves dissociative adsorption on metal nanoparticles.
- Homogeneous catalysts activate H2 via dihydride or dihydrogen intermediates at a single metal center.
Purpose of the Study:
- To investigate hydrogen activation by isolated Rh adatoms on Fe3O4(001).
- To elucidate the mechanism of hydrogen activation at the single-atom level.
- To establish a mechanistic link between homogeneous and heterogeneous catalysis.
Main Methods:
- Temperature-programmed desorption (TPD)
- X-ray photoelectron spectroscopy (XPS)
- Scanning tunneling microscopy (STM)
- Isotope-exchange experiments
- Density-functional theory (DFT) calculations
- Random-phase approximation (RPA) calculations
Main Results:
- Isolated Rh adatoms on Fe3O4(001) activate hydrogen, forming stable dihydride species.
- Hydrogen adsorption is strong (≈1 eV) and localized exclusively at isolated Rh sites.
- No atomic hydrogen spillover was observed.
- DFT and RPA calculations confirmed a barrierless conversion to the dihydride and its stability.
Conclusions:
- Single Rh atoms cleave hydrogen via a dihydride pathway, similar to homogeneous catalysts.
- This study establishes a mechanistic bridge between homogeneous and heterogeneous catalysis.
- Isolated single atoms can exhibit unique reactivity distinct from nanoparticles.
Keywords:
density functional theoryhydrogen adsorptionmetal‐oxide surfacesscanning tunneling microscopysingle‐atom catalysisMore Related Videos
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