archives@tulane.edu / Porous materials possess voids of varying size of and uniformity and are of great significance in many areas such as adsorption, separations, sensors, gas storage, and catalysts. Organic-inorganic hybrid materials, as one type of porous materials, combines hard and soft matter synergistically, and have attracted considerable attention. As the scientific community pushes the boundaries of hybrid materials, more complicated architecture have been developed to achieve the desired functionality. Multifunctional materials with elaborate designs of architecture, especially actives sites for certain applications are needed.
Dendrimer-encapsulated nanoparticles (DENs) have attracted interest since they were first introduced. This synthetic approach leads to well-defined sizes, compositions and structures of nanoparticles controlled by the dendrimer template. Melamine-based dendrimers were successfully grafted to OMS supports through an aminosilane handle. More recently the supported dendrimers were used as templates to form Palladium nanoparticles, resulting in encapsulated palladium/dendron-OMS materials. Multiple characterizations were used to validate both the structural integrity of the dendrimers and the nature of the metal nanoparticles formed. Probe reactions have shown the accessibility of both metal sites and amine sites from dendron. In this work, we used the organic architecture tethered to the support to not only make the metal nanoparticles while attached to the solid surface, but also utilize the metal and ligand functionalities of the resulting material. Multiple active sites indicate the dendron encapsulated palladium nanoparticles can be further used as multifunctional catalysts.
Support topology and dendron structure of the encapsulated palladium/dendron-OMS play important roles in the catalysis and capture performance. We studied how the pore structures influence the loading of dendron, further influence carbon dioxide capture properties. We also studied how the different types of amines in the dendron unit participate in binding multiple types of small molecules by designing similar dendrons with different peripheral nitrogen. Carbon dioxide uptake is controlled by the peripheral amines with little interior contribution. However, interior nitrogen atoms participate in metal binding and catalysis, though involved with different kinds of nitrogen types.
Sustainably meeting the growing energy needs of the planet is one of the 21st century’s grand challenges. Many pathways to meeting our energy needs while reducing fossil-fuel consumption have been posited, all with challenges. One possible route is to convert biomass into fuels. We utilized encapsulated palladium/dendron-OMS as multifunctional catalyst, they are used for multistep reaction. We designed a three-step process that includes hydrogenation of phenol, aldol condensation, and hydrogenation of aldol reaction product to produce fuels from oxygenates using palladium containing dendrons supported on OMS. The operating conditions of low temperature and low pressure hydrogen in aqueous media is consistent with green chemistry goals. / 1 / Yueyun Lou
| Identifer | oai:union.ndltd.org:TULANE/oai:http://digitallibrary.tulane.edu/:tulane_108427 |
| Date | January 2019 |
| Contributors | Lou, Yueyun (author), Shantz, F. Shantz (Thesis advisor), School of Science & Engineering Chemical and Biomolecular Engineering (Degree granting institution) |
| Publisher | Tulane University |
| Source Sets | Tulane University |
| Language | English |
| Detected Language | English |
| Type | Text |
| Format | electronic, pages: 182 |
| Rights | No embargo, Copyright is in accordance with U.S. Copyright law. |
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