Abstract
The thesis focused on the preparation of mesoporous SBA-15 silica based nanocomposite and their application in the propylene partial oxidation. In the first part, various metal salts were deposited in the micropores of the SBA-15 support and the influences of the nano-confinement of micropores on the structural and textural properties of the resulting nanocomposite materials after heat treatment at temperatures up to 800 °C were studied. The observations were discussed based on the surface free energy of metal oxides and the phase diagrams of metal oxide with silica. In the second part, a nanostructured Au/TiO2@SBA-15 catalyst has been prepared and applied in propylene epoxidation with a mixture of O2/H2. The nanocomposite catalysts exhibited relatively stable propylene oxide (PO) production with small amounts of propanal and acetone byproducts. The unique catalytic behavior is related to the unique structure of very small Au nanoparticles on nanosized TiO2 phases located in the micropores and the hydrophobicity of the mesopores, which avoids further conversion of the reaction product PO. In the third part, SBA-15-supported high loaded and highly dispersed copper catalysts were prepared by vacuum-thermal treatment and applied in the propylene partial oxidation by using molecular oxygen as oxidant. They exhibited excellent activity and high yield of acrolein. The high activities were associated with the high dispersion of the copper species. The results of this thesis indicated that the SBA-15 with hydrophobic mesopores is a unique support to prepare oxide-containing nanocomposite materials and showed that the rational catalyst design would possibly improve the catalytic performance.