Abinash Agrawal (Committee Member), Andrew Hsu (Other), George Huang (Other), Sharmila Mukhopadhyay (Advisor), Raghavan Srinivasan (Committee Member)
Master of Science in Engineering (MSEgr)
The effectiveness of metal-based catalysts can be significantly enhanced by increasing the available surface area relative to the volume through the creation of hierarchical nanostructures. The catalyst demonstrated here is palladium, which is a widely recognized heterogeneous catalyst suitable for a variety of industrial applications such as water purification, hydrogen storage, and electrochemical devices. In this study, a novel multi-scale supporting material developed in this group, has been used as support. It consists of micro-porous graphitic carbon with strongly attached carbon nanotubes. This can increase the surface area by orders of magnitude without increasing the size or weight while still maintaining structural integrity. This allows miniaturization of palladium catalysts structures that are lighter, smaller and more compact than conventional ones. Fabrication issues of these structures have been successfully addressed. Detailed micro-structural as well as spectroscopic analysis of the nanoparticles have been performed. Variations of palladium nanoparticles distribution with processing conditions, and the possible ways of controlling this distribution will be presented. Surface spectroscopic analysis indicates that these are zero-valent metallic palladium and do not degrade with time. The catalytic activity of palladium nanoparticles has been tested via bench-scale experiments for reductive dechlorination of carbon tetrachloride. It is seen that palladium functionalized carbon nanotubes is highly effective in the degradation of carbon tetrachloride and similar organic pollutants found commonly in drinking water sources. It was also demonstrated that palladium functionalized carbon nanotubes can be used repeatedly as the valence state of palladium does not change, and thus can be cost-effective. Future scope of these results and their connection to future device applications will be discussed.
Department or Program
Department of Mechanical and Materials Engineering
Year Degree Awarded
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