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Abrupt increase in hydrogen diffusion on transition-metal surfaces during hydrogenation catalysis
Juan Simonovis1, Francisco Zaera1
1Department of Chemistry and UCR Center for Catalysis , University of California , Riverside , CA 92521 , USA .
Chemical Science
|August 30, 2018
Summary
Hydrogen isotope scrambling accelerated on platinum catalysts during olefin hydrogenation. This was linked to increased hydrogen atom mobility on the catalyst surface.
Area of Science:
- Surface chemistry
- Catalysis
- Hydrogen isotope effects
Background:
- Hydrogen isotope scrambling is a key phenomenon in catalytic hydrogenation.
- Understanding surface mobility of hydrogen atoms is crucial for optimizing catalytic processes.
Purpose of the Study:
- To investigate the mechanism behind a sharp increase in hydrogen isotope scrambling during olefin hydrogenation.
- To elucidate the role of surface mobility of adsorbed species on catalytic activity.
Main Methods:
- Utilized platinum(111) catalysts for hydrogenation reactions.
- Employed mixtures of hydrogen (H2) and deuterium (D2) isotopes.
- Employed spectroscopic techniques to analyze surface species and their behavior.
Main Results:
- Observed a significant acceleration in hydrogen isotope scrambling rates.
- Spectroscopic data indicated a sudden increase in atomic hydrogen surface mobility.
- This mobility increase correlated with a decrease in the size of adsorbed hydrocarbon islands.
Conclusions:
- The observed increase in hydrogen isotope scrambling is attributed to enhanced atomic hydrogen surface mobility.
- Changes in hydrocarbon island size on the Pt(111) surface play a critical role in modulating hydrogen mobility and reaction rates.
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