Nanoporous materials for hydrogen and carbon dioxide adsorption

Nanostructured materials including metal-organic frameworks (MOF), ordered mesoporous carbon (OMC), clathrates and partially truncated fullerene were synthesized, characterized, and evaluated for H2 or CO2 adsorption to address the pressing energy and environmental issues. MOF-5 and MOF-177 were synthesized with modified approaches aiming at increasing the H2 storage capacity. Crystallographic, morphologic and structural properties of MOFs were examined and H2 adsorption equilibrium and kinetics on MOFs were determined volumetrically and gravimetrically at various conditions. MOF-5 adsorbs 11.8 wt.% of H2 at 120 bar and 77K, and MOF-177 adsorbs 19.6 wt.% of H2 uptake at 120 bar and 77K, both are probably the highest H2 adsorption amounts ever reported. The mixed crystals of MOF-5 and MOF-177 were also investigated for H 2 storage. The structural stability of MOF-177 was studied by monitoring its phase structure changes in ambient air and exposure to water with XRD and TGA.;Ordered mesoporous carbon was synthesized by a self-assembly or soft-templating approach and doped with Pd, Pt, Ni and Ru to explore the feasibility of storing H2 at ambient temperatures. The carbon adsorbents were characterized with XRD, Raman scattering, electron microscopy imaging and nitrogen adsorption for their physical and chemical properties. It was found that the H2 adsorption was enhanced after metal doping and the 1% Ni doped OMC has the highest H2 uptake of 2.14 wt.% at 300 bar and 298K.;Formation of tetrahydrofuran-H2 binary clathrate hydrates inside porous media was explored for H2 storage. OMC and other porous materials with various median pore sizes were used to determine the H2 clathrate formation kinetics. It was observed that the H 2 uptake increased due to the combined effect of physical adsorption and clathrate formation and the clathrate formation time was greatly reduced. Only 27 minutes were needed to form the tetrahydrofuran-H2 clathrate hydrates inside a porous medium with a median pore of 49A, which is probably the shortest time ever reported.;Partially truncated C60 fullerene was synthesized by controlled oxidations to open the buckyball structure and to explore its application in H2 storage. The H2 adsorption capacity was increased from 4 wt.% on the perfect C60 fullerene to 13 wt.% on the partially truncated C60 fullerene at 300 bar and 77K.;Adsorption equilibrium and kinetics of CO2, CH4, N2O and N2 on MOF-5 and MOF-177 and zeolite 5A were determined to assess their efficacy for CO2, CH4 and N2O removal from air and separation of CO2 from CH 4 in pressure swing adsorption processes. Zeolite 5A is a better adsorbent for removing CO2 and N2O from air and separation of CO2 from CH4 while MOF-177 is the adsorbent of choice for removing CH4 from air. However, both MOP adsorbents have larger adsorption capacities for CO2 and CH4 than zeolite 5A at elevated pressures, suggesting MOF-5 and MOF-177 are better adsorbents for CO2 and CH4 storage.