Physisorption and Chemisorption of SF6 by Transition Metal-Porphyrin Structure Embedded on Graphene Surface with Different Hapticities

The adsorption of sulfur hexafluoride (SF6) by a transition metal-porphyrin structure embedded on the surface of graphene (MN4-graphene) was evaluated using first-principles density functional theory calculations by constructing the adsorption energy profile. The mutual balance between physisorption and chemisorption was assessed by analyzing the characteristics of the interaction between each central metal atom as an adsorption center and the SF6 molecule. CaN4- and CrN4-graphene had moderate adsorption energies of about -1.5 eV. The results indicate the feasibility of these species as reusable SF6 adsorbents, even under ambient conditions. This study provides deeper insight into the adsorption of SF6 and the potential of transition metal-porphyrin structures as SF6 capture materials for mitigating global warming.