(633a) Synthesis and Characterization of Thermally Stable Nanoporous Gallium Oxide Phases

Gallium oxide represents a promising material mainly for catalytic, sensing and semiconductor applications. For example, crystalline gallium oxide has been used as a catalyst for the dehydrogenation of alkanes (ethane and propane) to alkenes (ethene and propene) in the presence of carbon dioxide. Also, gallium oxide which is a wide-band-gap semiconductor (Eg = 4.9 eV) exhibits luminescence and conduction properties and have potential applications in optoelectronic devices, high-temperature stable gas sensors and high- temperature/high-power electronic devices.

Here in, we report the synthesis of pure mesoporous gallium oxide by self assembly of inorganic species in the presence of supramolecular liquid crystalline phases. Gallium nitrate was used as the inorganic precursor and triblock co-polymers and CTAB as structure directing agents. The resulting thermally stable Ga2O3 phases were characterized by BET, N2 adsorption-desorption isotherms, pore size distribution, SEM, XRD, FTIR, Raman, and TGA. The use of P123, F127 and charged template CTAB as the structure directing agents led to the formation of mesoporous phases with BET surface area as high as 300 m2 g-1 displaying unimodal pore sizes in the 2 to 15 nm range. We found that, as the amount of templating agent increased (0.15-0.5g) the BET surface area increased and the pore size decreased. Hydrothermal treatment of the inorganic solution at 180-200oC and calcination at 600 K led to the formation of 4-5 µm mesoporous gallium oxide spheres. The resultant mesophases will be evaluated as catalysts in the oxidation of lower alkanes.

Keywords: Mesoporous Gallium Oxide, Catalytic applications.

*Corresponding author: macarr15@louisville.edu