Controlled Synthesis Of Porous Silver Catalyst Platinum / Iron Oxide Based Catalyst Hybrid Structure, Characterization, And Catalytic Properties

Noble metal nanocrystal has been one of the most important topics in recent years due to their excellent electronic, optical, and catalytic properties. Their applications in various areas were strongly dependent on their size and shape of the resultant nanocrystals, therefore, controlled and scablable synthesis of noble metal nanocrystals with optimal sizes and shapes become a great challenge for material scientists presently, which maybe due to their limited resources and high-cost, In this thesis, monolithic hierarchical porous silver monoliths can be obtained via facile solution based approaches, which can be considered as a good catalyst candidate in catalytic fields; in addition, we also successfully prepared a kind of iron oxide based Pt hybrids by simple solution synthetic method, the specific hybrids serve as novel magnetically separately catalysts can display excellent catalytic activity and high selectivity in hydrogenation reactions for different substrates. Detailed research results can be seen the following:1、Different of silver intermediate was firstly prepared via facile process by combining an aging treatment with a thermal-induced reduction reaction. The prepared samples are well characterized by means of SEM, XRD, FTIR and TGA to analysis the structure, morphology and mechanism. Hierarchical porous Ag was obtained after calcination, which are identified the purity of Ag sample and high crystallinity. Remarkably, the as-made porous Ag exhibit superior activity and durability in catalyze over reduction of4-NP. Their catalytic performance did not lose after10recycle.2、A kind of Ag nanowires were prepared by adjusting the amount of precursors and reductant, which is high-quality compared with these silver products obtined by using conventional hydrothermal synthesis methods. The experimental results show that Ag nanowires is also exerts highly catalytic activity over reduction of4-NP when the NaBH4as the reductive agent.3、A kind of unique Fe2O3/Pt hybrids consisting of uniform platinum nanoparticles deposited on nanoflake-shaped iron oxide support was prepared by using a facile solution synthetic route. Pt NPs are well-dispersed on the surface of flake-like Fe2O3and found to be narrow size distribution by SEM, TEM and size distribution. And numerous Pt NPs with an average size that ranged from3to6nm. Furthermore, the catalytic activity of the prepared Fe2O3/Pt catalyst was tested over the hydrogenation for a variety of nitro and unsaturated compounds. Results demonstrated that the Fe2O3/Pt catalyst displays high selective catalytic activity for the aromatic nitro and unsaturated compounds substrates. Furthermore, the prepared FeO3/Pt heterogeneous catalyst could be easily separated from the product mixture by using a magnet and could be recycled for10times without catalytic activity loss.