279898 Mesopore Formation During Zeolite Dry Gel Syntheses: A FIB/SEM Study

Wednesday, October 31, 2012
Hall B (Convention Center )
Gregory T. Neumann, Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, IN and Jason C. Hicks, Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, IN

Mesopore Formation during Zeolite Dry Gel Syntheses: A FIB/SEM Study

Gregory T. Neumann, and Jason C. Hicks*

Department of Chemical and Biomolecular Engineering, University of Notre Dame, IN

As a method to upgrade large molecular weight feedstocks, such as heavy oil, biomass and pyrolysis oil, zeolite materials have been synthesized to contain both mesopores and micropores within the crystalline particles.  These hierarchical materials have been reported to enhance the diffusion of many larger molecular weight molecules while maintaining catalytic activity and selectivity.  Several synthesis methods exist that introduce mesopores within the catalyst particles: 1) destructive, post synthesis silicon etching, 2) constructive, dual templating methods using either hard or soft mesoporous templates, and 3) constructive, assembly of zeolite nanocrystals around mesopore templates.  Here we report the results of mesopore formation in HZSM-5 using a dual templating dry gel synthesis method followed by steam assisted crystallization.  Using the combination of focused ion beam (FIB) coupled with scanning electron microscopy (SEM), mesopore formation was investigated for materials steamed at various times using different soft mesopore templates and additives.  Additionally, these materials were characterized by X-ray diffraction (XRD), N2 physisorption, and NH3 temperature-programmed desorption (NH­­3-TPD).


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