Porous polymeric materials for hydrogen storage
A porous polymer, poly-9,9′-spirobifluorene and its derivatives for storage of H 2 are prepared through a chemical synthesis method. The porous polymers have high specific surface area and narrow pore size distribution. Hydrogen uptake measurements conducted for these polymers determined a higher hydrogen storage capacity at the ambient temperature over that of the benchmark materials. The method of preparing such polymers, includes oxidatively activating solids by CO 2 /steam oxidation and supercritical water treatment.
1. A hydrogen storage system including an organic polymer product, characterized by the improvement that the organic polymer comprises a porous polymer prepared by cross-linking of a plurality of a stereo-contorted core monomer component having a structure selected from the group of a spiral core structure and tetrahedral core structure and forming a benzene ring from the plurality of the cross-linked stereo-contorted core monomer component.
2. The hydrogen storage system as defined in claim 1 , wherein the stereo-contoured core monomer component is selected from the group consisting of 9,9′-spirobifluorene and tetraphenyl methane and functionalized derivatives thereof having a terminal group selected from the group of acetylene, ethynnylphenyl and thienyl.
3. A hydrogen storage system including an organic polymer product, characterized by the improvement that the organic polymer comprises a porous polymer prepared by cross-linking of a plurality of a stereo-contorted core monomer component having a structure selected from the group of a spiral core structure and tetrahedral core structure and further including functionalized forms of the monomer component comprised of a terminal group selected from a group consisting of acetylene, ethynylphenyl and thienyl.
4. The hydrogen storage system as defined in claim 1 , wherein the polymer is prepared by cross-linking of monomers selected from the group consisting of 2,2′,7,7′-tetraethynyl-9,9′-spirobifluorene, tetra(4-ethynylphenyl)methane, 2,2′,7,7′-Tetrakis-(2-thieny)-9,9′-spirobifluoene.
5. A hydrogen storage system including an organic polymer, characterized by the improvement in that the organic polymer comprises a porous polymer prepared by cross-linking of a stereo-contorted core monomer having a structure selected from the group of a spiral core structure and tetrahedral core structure wherein the stereo-contorted core monomer component comprises functionalized groups including at least one of acetylene terminal groups and extended acetylene terminal groups.
6. The hydrogen storage system as defined in claim 5 wherein the stereo-contorted core monomer component is selected from the group of poly 9,9′-spirobifluorene, tetraphenyl methane and functionalized derivatives thereof having a terminal group selected from the group of acetylene, ethynylphenyl and thienyl.
7. The hydrogen storage system as defined in claim 6 wherein the functionalization of the stereo-contorted core monomer component is accomplished by reaction steps i-iii where step i comprises a bromination reaction through which Br is attached to a contorted core monomer; step ii comprises a coupling reaction between said Br in the step i and components selected from the group of (trimethylsilyl)acetylene, 4-(trimethylsilylethynyl)phenyl boronic acid, or 2-tributyltin thiophene), where the Br is replaced by R(R=trimethylsilyethynyl, 4-(trimethylsilylethynyl)phenylene, and thienyl; and step iii comprises removal of the trimethylsilyl component.
8. The hydrogen storage system as defined in claim 1 wherein the polymer is processed by a step of stabilizing the stereo-contoured core monomer component by temperature cycling treatments.
9. The hydrogen storage system as defined in claim 8 wherein the polymer is processed by a flowing CO 2 /steam source.
10. The hydrogen storage system as defined in claim 9 wherein the flowing CO 2 /steam source process includes loading the polymer in a packed bed configuration in a reactor and heated by a furnace.
11. The hydrogen storage system as defined in claim 9 wherein the CO 2 /steam source is selected from the group of a flowing CO 2 /H 2 O fed directly to the reactor and a mixture of CO 2 /H 2 O with a non-reactive gas diluent.
12. The hydrogen storage system as defined in claim 1 wherein the polymer is processed by placing the polymer in a supercritical water reactor, mixed the polymer with high purity water, closing the reactor, and increasing temperature and pressure in the reactor above water's triple point of supercriticality.
13. The hydrogen storage system as defined in claim 12 where the temperature ranges between about 375° to 500° C.
14. The hydrogen storage system as defined in claim 12 wherein the pressure is above about 221 bar.
15. The hydrogen storage system as defined in claim 12 wherein time at the temperature is about 30 minutes to 4 hours.
16. The hydrogen storage system as defined in claim 1 wherein the porous polymer includes pores having a diameter of about 0.3 nm to 1.0 nm.
17. The hydrogen storage system as defined in claim 2 wherein the functionalized derivatives are selected from the group of 2,2′,7,7-tetraethynyl-9,9-spirobifluorene, tetra(4-ethynylphenyl)methane, 2,2′,7,7′-Tetrakis-(2-thieny)-9,9′-spirobifluoene.
18. The hydrogen storage system as defined in claim 3 wherein a homo-coupling reaction is used to prepare the polymer from the monomer component containing thieny functional group.