Metal-organic frameworks for the adsorption and catalytic transformations of carbon dioxide
Novel crystalline porous materials known as metal-organic frameworks (MOFs) and methods for their synthesis are provided herein. The MOFs include a M 6 (μ 3 -OH) 8 (OH) 8 (μ 2 ,η 2 -(O 2 C) 2 cyclam) 8 cluster, and a metal atom coordinated to the one or more cyclam of the cluster, wherein M is Zr or Hf, and the metal atom is any one of Cu, Ni, Cr, Ru, Co, and Gd. The MOFs can be used as an adsorbent, alone or in a medium with other components, of CO 2 . The MOFs can also be used as a catalyst for the transformation of CO 2 and epoxides to cyclic carbonates. The MOFs can also be used in the electrochemical catalytic reduction of CO 2 . The MOFs can also be used for photocatalytic CO 2 reduction for the production of carbon-based fossil fuels. The MOFs can also be used for light-induced nitric oxide (NO) release. The MOFs can also be used as magnetic resonance imaging (MRI) agents.
1. A metal-organic framework (MOF), the MOF comprising:
a M 6 (μ 3 -OH) 8 (OH) 8 (μ 2 ,η 2 -(O 2 C) 2 cyclam) 8 cluster; and
a metal atom coordinated to the one or more cyclam of the cluster,
wherein
M is Zr or Hf, and
the metal atom is any one of Cu, Ni, Cr, Ru, Co, and Gd.
2. The MOF of claim 1 , wherein M is Zr.
3. The MOF of claim 2 , wherein the metal atom is Cu, Ni or Co.
4. The MOF of claim 2 , wherein the metal atom is Cu or Ni.
5. The MOF of claim 2 , wherein the metal atom is Cr or Ru.
6. The MOF of claim 2 , wherein the metal atom is Co.
7. The MOF of claim 2 , wherein the metal atom is Gd.
8. The MOF of claim 1 , wherein the MOF has a BET surface area of about 340 to about 620 m 2 /g.
9. The MOF of claim 1 , wherein the MOF has a crystal structure characterized by a I4/m space group.
10. An electrochemical CO 2 reduction system, the system comprising:
a conductive substrate; and
a film coated on a surface of the conductive substrate, the film comprising an MOF according to claim 1 .
11. A CO 2 adsorbent medium, the medium comprising an MOF according to claim 1 .
12. A method for removing CO 2 from a mixture of gases, the method comprising reacting the mixture of gases with an adsorbent medium according to claim 11 .
13. The method of claim 12 , wherein the temperature of the mixture of gases is between about 273 K and about 296 K.
14. The method of claim 12 , wherein the pressure of the mixture of gases is about 1 atm.
15. A method of synthesizing a cyclic carbonate, the method comprising:
reacting CO 2 and an epoxide in the presence of a catalyst, wherein the catalyst is a MOF according to claim 1 .
16. The method of claim 15 , further comprising recovering the catalyst after cyclic carbonate synthesis is complete.
17. The method of claim 16 , further comprising reusing the recovered catalyst in a subsequent cyclic carbonate synthesis procedure.
18. A magnetic resonance imaging (MRI) contrast agent, the MRI contrast agent comprising an MOF according to claim 1 .
19. The MRI contrast agent of claim 18 , wherein M is Zr and the metal atom is Gd.