NMP 2008

	Won Cheol Yoo
	ADVISOR: Andreas Stein Chemistry Department University of Minnesota

Study of Zeolite Growth within 3-D Ordered Macroporous (3DOM) Carbon Nanoreactor

 

Won Cheol Yoo1, Sandeep Kumar2, Alon McCormick2, Marc A Hillmyer1, R Lee Penn1, Michael Tsapatsis2, Andreas Stein1

1Department of Chemistry, University of Minnesota
2Department of Chemical engineering and Materials Science, University of Minnesota

For advanced applications of zeolites, including thin, defect-free catalytic membranes with high efficiencies, growth and aggregation of zeolite nanoparticles must be controlled to obtain monodisperse zeolite particles with desired sizes. To this effect, we have investigated the concept of zeolite growth within massively parallel arrays of "nanoreactors" with sub-100 nm interconnections that can prevent transport of solid products but still provide access to precursors into each nanoreactor. The reactors consisted of thermally and chemically stable 3-dimensionally ordered macroporous (3DOM) carbon, produced by polymerization and carbonization of resorcinol-formaldehyde or phenol-formaldehyde precursors within colloidal crystals. The macropore arrays in 3DOM carbon had typical diameters around 300 nm and interconnecting windows <100 nm in diameter. After appropriate surface functionalization of the carbon, siliceous MFI zeolite was hydrothermally grown within the pore confinement of 3DOM carbon. The development of the MFI morphology and crystallinity during seed growth were monitored by scanning electron microscope, transmission electron microscope and X-ray diffraction. After multiple seed growth steps, fully crystallized MFI filled the nanoreactors, and monodisperse MFI particles were produced by removal of the carbon framework and structure direction agent (tetrapropylammonium hydroxide) after calcination.