Synthesis Of Mesoporous Ce0 ₂ -C Complex By Lyotropic Liquid Crystal Template Technique

Cerium oxide has been shown to be an important catalyst and carrier because of the oxygen vacancy defects in their surface. However, continuous operation at high temperature generally leads to sintering of MNPs. Therefore, the work of this paper focused on the use of carbon-based carrier, stably loading cerium oxide nanocatalyst and further load precious metal nanoparticles.The thesis is composed of four chapters. The first chapter is a literature review, including the synthesis and applying of mesoporous material, and the structure and property of cerium oxide.The second chapter presents synthesis of a new type of Mesoporous Ce O2 –C nano materials, using the triblockcopolymer F127 as a structure-directing agent,ethanol as solvent, low molecular weight phenolic resin as carbon source, Cerium nitrate hexahydrate as cerium source, we can get Mesoporous Ce O2 –C with small Ce O2. So the stability and catalytic activity of the Ce O2 can be improved. Adjust the dosage of the Ce(NO3)3·6H2O, different content of Ce O2 nano materials are obtained. Small-angle XRD, TEM and N2 sorption results reveal that the catalysts have the ordered 2-D hexagonal mesostructure, high surface areas(~833 m2/g), large pore volumes(~0.53 cm3/g), uniform pore sizes(~3.6 nm). And the 2-3 nm Ce O2 nanoparticles are highly dispersed in the mesoporous carbon wall, No obvious particle reunion and phase separation phenomenon.The FTIR indicats a hydrogen-bondinginteraction between the ethoxy groups of the Pluronics and coordinated water molecules of metal ions(Ce-O(H)H----O(CH2CH2)2),confirming that Ce ions are in the lyotropic liquid crystal template agent, Metal ions in the PEO block.In chapter three, We use the obtained Ce O2- C carrier, further load noble metal Pd, Au nanoparticle. But 19 nm Au nanoparticle has been obtained through Sediment precipitation method and ordered structure can not be obtained when we use Sol gel method. During One-step method, thiol has been used to control the size of gold(9 nm) and we obtain the Au-Si O2-Ce O2-C catalyst. Pd/Ce O2-C has been synthesised through the impregnation method. And its application is to be used in the Suzuki coupling reaction.The last chapter is summary of the whole work.