The catalysis market is responsible for more than 35% of the world’s GDP and it is involved in the most successful industrial sectors: energy generation, chemicals, and pharmaceuticals. Despite the remarkable advances in catalytic technologies, the industry still faces thermal management issues and accumulation of heat on reactor walls. To overcome thermal transport problems, heat can be generated in situ with the utilization of iron oxide (Fe3O4) nanoparticles. Traditionally, Fe3O4 is heavily used in magnetic hyperthermia studies where radio waves (RF) are used to generate heat within the particle, which has not yet been applied to catalysis. The utilization of Fe3O4 nanoparticles in catalysis is beneficial since its purpose would be twofold: an improvement in energy transport and the utilization of the particles as catalysts as well. For dehydrogenation reactions, for example, Fe3O4 acts as a great reducing agent, and its structure can be tuned such that it is functionalized according to the catalytic necessities of each reaction. In this work, ~20 nm anisotropic iron oxide nanoparticle spheres, cubes, and truncated octahedrons of tunable sizes are investigated for RF induced catalysis. By varying surfactant to precursor ratio in thermal decomposition reactions, exposed Fe3O4 facets are controlled. These facets allow surface activity control and heat generation, key parameters in the development of high selectivity catalysis. Specific Absorption Rate (SAR) measurements of these nanoparticles were performed in organic solvents achieving values as high as 200 W/gFe, which is 34% higher than commercially available nanoparticles tested under similar conditions. After surface functionalization, particles were also dispersed in alcohols to perform the catalytic production of acetaldehydes and ketones. These reactions were performed in the presence of RF and the results were compared to thermally activated systems. This RF driven catalytic reaction has also been investigated via in situ neutron scattering to identify the reaction pathway and particle-molecule interactions for the dehydrogenation of ethane. Furthermore, the Fe3O4 valence levels are probed via ultraviolet photoelectron spectroscopy to identify particle-molecule interactions. Although further optimization is required, future work includes surface functionalization to apply this technology to a range of catalytic reactions.

Catalytic activity of anisotropic magnetic nanoparticles activated via RF induction heating

255th National Meeting (2018)

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