Chem. Mater. 2004, 16, 2869-2880
2869
SiC/MCM-48 and SiC/SBA-15 Nanocomposite Materials Piotr Krawiec,† Claudia Weidenthaler, and Stefan Kaskel*,† Max-Planck-Institut fu¨ r Kohlenforschung, Kaiser-Wilhelm-Platz 1, D 45470 Mu¨ lheim an der Ruhr, Germany Received August 8, 2003. Revised Manuscript Received December 5, 2003
Silicon carbide (SiC) was infiltrated into the ordered mesoporous molecular sieves MCM48 and SBA-15 using chemical vapor infiltration (CVI) of dimethyldichlorosilane (DDS) and hydrogen as the carrier gas. The infiltration process was followed ex situ using nitrogen physisorption measurements, small- and wide-angle X-ray diffraction, X-ray photoelectron spectroscopy, IR spectroscopy, and transmission electron microscopy. For MCM-48, infiltration at lower temperatures (1023 K) affords a thin, X-ray amorphous, SiC-based coating on the inner surface of the molecular sieve and the pore size of the mesoporous host decreases from 2.4 nm into the micropore regime (