287924 Templated Growth of Three-Dimensionally Ordered Mesoporous (3DOm) Zirconia Materials As Tunable Catalysts for Biomass Conversion

Monday, October 29, 2012
Hall B (Convention Center )
Daniel Gregory and Mark A. Snyder, Department of Chemical Engineering, Lehigh University, Bethlehem, PA

Liquid phase processing of sugars into furan based compounds, as opposed to traditional vapor phase methods involved in hydrocarbon processing, demands a new breed of hydrothermally stable catalytic supports with a three dimensionally ordered mesoporous (3DOm) or hierarchically micro-mesoporous pore topology capable of accommodating the transport of bulky sugars within the catalytic framework.  Zirconia offers a promising candidate for such supports due to its hydrothermal stability and surface properties.  This work examines the use of sol-gel based zirconia precursors to prepare 3Dom zirconia through a hard templating technique. Dynamic light scattering was used to select two candidate solutions (zirconium(IV) propoxide and zirconyl chloride octahydrate) for infiltration of a pre-formed mesoporous template.  The solutions were successfully templated with 3Dom carbon, resulting in monoclinic and tetragonal 3Dom zirconia upon high-temperature sacrifice of the carbon scaffold. Crystallinity was characterized with X-Ray diffraction; while, nitrogen adsorption provided insight into pore size tunability and resistance to collapse.  Transmission electron microscopy was used to assess structural integrity and development at various stages during calcination, and suggests significant size variation of ordered, interconnected zirconia domains during high-temperature curing. As a result, the effect of synthetic preparation parameters on pore evolution is currently being investigated in order to develop zirconias with both a micro and mesoporous structure.

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