NANO MFI ZEOLITE: SYNTHESIS AND CHARACTERIZATION

OSCAR A. ANUNZIATA; MARIA L. MARTINEZ; MARCOS GÓMEZ COSTA

Cancún, México

Congreso; XVIII International Materials Research Congress. “New Catalytic Materials”; 2009

Materials Research Society

The synthetic zeolites are used widely as catalysts or adsorbents in petrochemicals production, fine Chemistry, environmental process, etc. Thus, the search of new properties of known zeolites continues to be a subject of scientific research, where a recent trend is the synthesis of zeolitic materials with a low dimensionality size range. The properties and applications depend on the chemical composition, crystal size, crystal thickness and surface chemistry [1]. Therefore, assessing the critical parameters of the nanosized zeolite crystallites is crucial for future applications of these materials. Thus, this work focuses on the synthesis of MFI type crystallites with low dimensions in the size range between 10 - 30 nm. Nanometric MFI Zeolites were synthesized using smooth reaction conditions: 80 - 100 °C, 1 atm, diluted in tetrapropylammonium hydroxide (TPAOH), fumed silica (CAB-O-SIL) and Al2(SO4)3 and 15-Crown-15 ether as a co-template. XRD, FTIR, NMR-MAS and HRTEM indicated that ZSM-5 nanocrystals exhibited an aluminosilicate framework with a disc form, Pnma symmetry and dimension of pore, i.e., along [010] around 0.56 nm. The mean crystallite sizes along [020] and [200] were 20 and 46 nm, respectively. By NMR-MAS of 27Al we obtained the AIV/AVI ratios after 2, 4 and 9 days of synthesis,i.e., AIV/AVI = 0.85; 0.9 and 1, respectively. [1] L. Tosheva, V. P. Valtchev, Chem. Mater., (2005) 17, 2494-2513. [1] L. Tosheva, V. P. Valtchev, Chem. Mater., (2005) 17, 2494-2513. [1] L. Tosheva, V. P. Valtchev, Chem. Mater., (2005) 17, 2494-2513. [1] L. Tosheva, V. P. Valtchev, Chem. Mater., (2005) 17, 2494-2513.