Formation of ZSM-5 on Silicon Carbide Fibers for Catalytic Support

Abstract

ZSM-5 crystals were grown on the SiC fiber surface which was prepared by melt-spinning of polycarbosilane, silicon based preceramic polymer. To improve the bonding property between ZSM-5 crystals and SiC fiber, 200 nm of SiO 2 layer was formed on the fiber surface by simple oxidation before hydrothermal reaction in the autoclave because it was compositionally similar to ZSM-5 and relatively easy to form on the SiC fiber. During the process, 1 μm of zeolite crystals were very uniformly grown on the fiber surface. Weak X-ray diffraction (XRD) peaks observed between 10° and 30° showed that crystal structure of them were accorded to ZSM-5 structure. They were broken away with SiC fiber support during fracture test which mean that they were strongly bonded to fiber surface. This type of SiC based catalysts are expected for high-temperature gas-phase reaction, especially strong acid base conditions.