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Experimental Study of the Relationship Between Particle Size and Methane Sorption Capacity in Shale
Published on: August 2, 2018
Physisorption-induced C-H bond elongation in methane
H Oström1, H Ogasawara, L-A Näslund
1Stockholm University, AlbaNova University Center, Fysikum, SE-106 91 Stockholm, Sweden.
Physical Review Letters
|May 23, 2006
Summary
Methane physisorption on platinum surfaces creates new electronic states. This occurs due to orbital mixing and charge polarization, minimizing repulsion and slightly elongating C-H bonds without forming chemical bonds.
Area of Science:
- Surface Science
- Physical Chemistry
- Computational Chemistry
Background:
- Understanding gas-surface interactions is crucial for catalysis and materials science.
- Methane adsorption on platinum is a fundamental system with implications for various chemical processes.
Purpose of the Study:
- To investigate the electronic structure changes during methane physisorption on a platinum surface.
- To elucidate the mechanisms behind the observed electronic states and their relation to molecular geometry.
Main Methods:
- X-ray absorption spectroscopy (XAS) was employed to probe electronic states.
- Density functional theory (DFT) calculations were used to model and interpret the experimental spectra.
Main Results:
- New electronic states were observed upon methane physisorption.
- These states arise from orbital mixing, leading to charge polarization.
- A slight elongation (0.09 Å) of the C-H bond was detected in the physisorbed state.
Conclusions:
- Orbital mixing and charge polarization are key mechanisms in methane physisorption on Pt.
- These effects help minimize Pauli repulsion between methane and the Pt surface.
- The observed phenomena occur without the formation of covalent chemical bonds.
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