A Theoretical Study on Methane C-H Bond Activation by Bare [FeO]+/0/
Yang Wang1, Xiaoli Sun1, Jun Zhang2
1Institute of Theoretical Chemistry, Jilin University , Changchun 130023, People's Republic of China.
The Journal of Physical Chemistry. A
|March 25, 2017
Summary
This study explores methane C-H bond activation by iron oxide (FeO) using computational methods. The cationic FeO species exhibits the lowest activation barrier, with mechanisms varying by charge state.
Area of Science:
- Computational Chemistry
- Quantum Chemistry
- Catalysis
Background:
- Methane C-H bond activation is crucial for converting natural gas into valuable chemicals.
- Iron oxide (FeO) is a potential catalyst for methane activation.
- Understanding the influence of charge states on FeO's catalytic activity is essential.
Purpose of the Study:
- To investigate the first C-H bond activation of methane by bare diatomic FeO in cationic, neutral, and anionic states.
- To evaluate the performance of various density functionals and high-level computational methods for this reaction.
- To elucidate the reaction mechanisms and energy barriers involved in methane activation by FeO.
Main Methods:
- Density Functional Theory (DFT) calculations using 10 popular density functionals.
- Coupled Cluster Single Double (CCSD) and CCSD(T) methods for structural optimization and energy calculations.
- Analysis of electronic structure to determine reaction mechanisms.
Main Results:
- The cationic FeO system exhibits a lower activation barrier compared to neutral and anionic systems.
- The impact of density functionals on energy calculations is generally more significant than structural variations.
- The anionic FeO system shows the least sensitivity to different density functionals.
- Cationic and neutral systems proceed via hydrogen-atom transfer (HAT) or proton-coupled electron transfer (PCET).
- The anionic system exclusively follows a proton transfer (PT) mechanism.
Conclusions:
- The charge state of diatomic FeO significantly influences methane C-H bond activation barriers and mechanisms.
- Computational method selection, particularly density functionals, impacts energy predictions.
- This fundamental understanding aids in designing advanced catalysts for methane conversion.
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