Abstract
This thesis includes the review on the recent progress of mesoporous silicas and metal-containing mesoporous materials as well as the report on preparation and characterization of highly dispersed palladium nanoparticles containing mesoporous silicas MCM-41 and MCM-48 which were prepared through one-pot synthesis. The complex-surfactant aggregates [CTA]2[PdBr4] were considered to be generated in the presence of a large amount of CTAB. The synthesis of MCM-41 mesophase templated by CTA+ surfactant and the generation of PdO species through the reaction between [PdBr4]2□ and hydroxide anion may occur simultaneously. Those PdO nanoparticles were reduced to Pd metal by hydrogen treatment and found to stay inside the mesochannels of MCM-41 as detected by TEM, XAS, and PXRD. In hydrothermal synthesis of Pd/MCM-48, Pd nanoparticles of average size 7 nm were found to be deposited on the MCM-48, probably derived from ethanol reduction of Pd (II) complex. Moreover, the template removal from MCM-41 was observed to be catalyzed by Pd(0) nanoparticles.