Publications by authors named "Cameron L Roman"

Anion engineering has proven to be an effective strategy to tailor the physical and chemical properties of metal oxides by modifying their existing crystal structures. In this work, a low-temperature synthesis for rare earth (RE)-doped YOSO and YOS was developed via annealing of Y(OH) intermediates in the presence of elemental sulfur in a sealed tube, followed by a controlled reduction step. The crystal structure patterns (X-ray diffraction) and optical spectra (UV-IR) of YOSO, YOS, and crystalline YO were collected throughout the treatment steps to correlate the structural transformations (via thermogravimetric analysis) with the optical properties.

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We demonstrate that for polyethylene depolymerization with induction heating (IH), using a bifunctional (Pt- or Pt-Sn-containing zeolite) hydrocracking catalyst, we can obtain high hydrocarbon product yields (up to 95 wt % in 2 h) at a relatively low surface temperature (375 °C) and with a tunable product distribution ranging from light gas products to gasoline- to diesel-range hydrocarbons. Four zeolite types [MFI, LTL, CHA(SSZ-13), and TON] were chosen as the supports due to their varying pore sizes and structures. These depolymerization results are obtained at atmospheric pressure and without the use of H and result in an alkane/alkene mixture with virtually no methane, aromatics, or coke formation.

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Radio frequency (RF) induction heating was compared to conventional thermal heating for the hydrogenation of oleic acid to stearic acid. The RF reaction demonstrated decreased coke accumulation and increased product selectivity at comparable temperatures over mesoporous FeO catalysts composed of 28-32 nm diameter nanoparticles. The FeO supports were decorated with Pd and Pt active sites and served as the local heat generators when subjected to an alternating magnetic field.

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Heat management in catalysis is limited by each material's heat transfer efficiencies, resulting in energy losses despite current thermal engineering strategies. In contrast, induction heating of magnetic nanoparticles (NPs) generates heat at the surface of the catalyst where the reaction occurs, reducing waste heat via dissipation. However, the synthesis of magnetic NPs with optimal heat generation requires interfacial ligands, such as oleic acid, which act as heat sinks.

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