NameLee, JeongYong (author), Li, Jing (chair), Hall, Eugene (internal member), Warmuth, Ralf (internal member), Pan, Long (outside member), Rutgers University, Graduate School - New Brunswick,
SubjectChemistry and Chemical Biology,
DescriptionOne of the strategic goals of seeking for renewable energy sources/carriers that are clean and abundant is to replace fossil fuel with alternative fuel such as hydrogen gas. The U.S. Department of Energy has set forth specific cost and performance targets for utilizing hydrogen and natural gas for commercial purpose. In this study, a series of porous [M(L)(P)0.5] materials (where, M2+=Zn, Co, Ni, Cu; L (or linker) = obba, bdc, ndc; P (or pillar) = bpy or ted) were synthesizes via solvothermal reactions and evaluated on their ability of hydrogen and methane storage. By incorporating L groups with different length, microporous metal-organic framework (MOF) structures having controlled pore sizes were constructed. Single crystal X-ray diffraction study showed that they possess up to 60 % free space and the diameters of the pores are in the range of 3.5 ?? ~ 9 ??. The tunable and permanent porosity and gas storage capacity of these materials were explored by low and high pressure sorption study. At low pressure high resolution argon sorption experiments revealed that these MOF materials have very high surface area, up to 3282 m2/g. The hydrogen sorption study showed that reversible hydrogen adsorption/desorption can be achieved with pore size larger than 6 ??. From the high pressure hydrogen study, a 5.48 wt% of hydrogen uptake was achieved at 77 K and ~60 bar on [Ni(ndc)(ted)0.5], and 36 g/L of high volumetric density was also observed for [Zn(bdc)(ted)0.5] at the same temperature and ~40 bar. The interaction between hydrogen and MOF materials was analyzed in terms of isosteric heat of adsorption. Generally, a range of 5.0 ~ 7.5 kJ/mol of heat of adsorption energy was found for the structures investigated. These findings suggest that physisorption is the primary force of hydrogen adsorption on the internal surface of MOF materials. Crystals of [Zn(bdc)(ted)0.5] exhibit high methane storage capability at 298 K, as well as separation capability between hydrogen and methane gas, as several other selected MOF materials.
NoteIncludes bibliographical references.
CollectionGraduate School - New Brunswick Electronic Theses and Dissertations
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