Gas adsorption and gas mixture separations using mixed-ligand MOF material
A method of separating a mixture of carbon dioxiode and hydrocarbon gas using a mixed-ligand, metal-organic framework (MOF) material having metal ions coordinated to carboxylate ligands and pyridyl ligands.
1. A method of separating carbon dioxide from a gas mixture, comprising contacting the mixture and a material having a mixed-ligand, metal-organic framework that includes dicarboxylate ligands and dipyridyl ligands wherein the material selectively adsorbs carbon dioxide.
2. The method of claim 1 wherein the material is represented by the formula Zn 2 (NDC) 2 (DPNI) where NDC represents 2,6-naphthalenedicarboxylate and DPNI represents N,N′-di-(4-pyridyl)-1,4,5,8-napthalene tetracarboxydiimide.
3. The method of claim 2 including using the material made by heating reactants in a fluid heating bath.
4. The method of claim 3 wherein the reactants comprise Zn(NO 3 ), H 2 NDC, and DPNI in a solvent.
5. The method of claim 2 including using the material made by microwave heating of reactants.
6. The method of claim 5 wherein the reactants comprise Zn(NO 3 ), H 2 NDC, and DPNI in a solvent.
7. The method of claim 1 wherein said gas mixture includes a hydrocarbon gas.
8. The method of claim 7 wherein the hydrocarbon gas comprises methane, propane, and/or propylene.
9. The method of claim 1 that separates carbon dioxide from natural gas.
10. The method of claim 1 that separates carbon dioxide from landfill gas.
11. The method of claim 1 further including the step of substantially reversible carbon dioxide desorption from the material.
12. The method of claim 1 that uses the pressure swing adsorption process for separation of the mixture.