(177a) Tuning External Surface and Textural Properties of Unit-Cell Thick Pillared MFI and Pillared MWW Zeolites By Atomic Layer Deposition and Its Consequence on Catalytic Reactions

Authors: 
Liu, D., University of Maryland
Zhang, J., Oak Ridge National Laboratory
The pillared MWW (PMWW or MCM-36) and pillared MFI (PMFI) zeolites are 2-dimensional (2D) catalytically active materials made by pillaring of layered MCM-22(P) and multilamellar MFI precursors, respectively. The single- or near single-unit-cell thick 2D microporous layers in PMWW and PMFI expose comparable external surface areas to those in micropores, which become important or dominant contributor to the catalytic properties. Although the acidity and catalytic activities of PMWW and PMFI have been studied, modification of their external surfaces and its implications on catalytic reactions are not available. In this talk, we will present the tailoring of external surfaces of PMWW and PMFI zeolites by atomic layer deposition (ALD) of silicon (ALD-Si), titanium (ALD-Ti) and aluminum (ALD-Al), respectively. The textural, acidic and catalytic properties of the ALD modified pillared zeolites were investigated using a variety of characterization methods. The effects of ALD-Al, ALD-Ti and ALD-Si modifications on the pillared MFI and pillared MWW zeolites were comparatively quantified and analyzed.