An investigation of paddle wheel Cu₂(μ₂-O₂CCH₃)₄ for gas molecule adsorptions

Abstract

Metal organic frameworks (MOFs) have been well-known and extensively researched due to the high storage /good selectivity for gas molecules. Herein, the structures and electron paramagnetic resonance (EPR) spectra for dicopper paddle wheel MOF compound (Cu₂(µ₂-O₂CCH₃)₄ with various gas molecule are theoretically investigated by density functional theory (DFT) calculations. The adsorption energies and isotherms (including pure gas molecules and the mixed ones) are calculated for the gas molecules interacting with the unsaturated Cu₂(µ₂-O₂CCH₃)₄. Both quantities exhibit the roughly consistent orders (e.g. H₂S > NH₃ > CO₂ > CO > H₂O > N₂ > NO > H₂ for isotherms and H₂S > NH₃ > N₂ > CO₂ > NO > H₂O > H₂ > CO for adsorption energies), possibly suggesting that this material may act as a potential adsorbent of these gas molecules. The catalytic property of Cu₂(µ₂-O₂CCH₃)₄ for oxidation of CO and NO into non-toxic molecules and splitting of H₂O into H₂ and O₂ in the solvent condition are uniformly discussed. Simulation of Grand Canonical Monte Carlo (GCMC) in MS 8.0 and calculations in Langmuir model reveal that Cu₂(µ₂-O₂CCH₃)₄ has good selectivity for CH₄ in natural gas (CH₄/CO₂/N₂) and SO₂ in fog (SO₂/NO/NO₂/H₂O/O₂), which would exhibit potential environmentally friendly applications.

GRAPHICAL ABSTRACT

KEYWORDS:

• Density functional theory (DFT)
• electron paramagnetic resonance (EPR)
• Cu₂(µ₂-O₂CCH₃)₄
• adsorption behaviours

Acknowledgements

This work was financially supported by the National Natural Science Foundation of China Granted No. 11764028 and the Sichuan Province Academic and Technical Leaders Support Fund [Y02028023601041]. Great thanks are also given to Prof. Kai-Lai Xu of Key Laboratory of Green Chemistry & Technology of Ministry of Education, Sichuan University for her help in MS 8 calculations.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was financially supported by the National Natural Science Foundation of China [granted number 11764028] and the Sichuan Province Academic and Technical Leaders Support Fund [grant number Y02028023601041]. Great thanks are also given to Prof. Kai-Lai Xu of Key Laboratory of Green Chemistry & Technology of Ministry of Education, Sichuan University for her help.