Metallic Nanomaterials: Synthesis And Catalytic Application

Nano-materials with a huge surface area, excellent oriented adsorption effect and quantum size effects, are expected to act as catalysts with high efficiency, high selectivity for the molecular transformation.Here, we reported the wet-chemical synthesis of Pt @ Fe₂O₃, FePt @ Cu and Pt nanowires with narrow size-distributation via thermal decomposition method. These nanowires were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), energy dispersive X - ray analysis (EDS), respectively. We further analysized the catalytic abilities of these nanowires (NWs) in the oxidation and reduction reactions.(1) Pt@Fe₂O₃ nanowires with 3 nm in diameter were firstly synthesized via thermal decomposition and surface oxidation methods for selective oxidation of olefins and alcohols. We optimize the reaction conditions on the reaction solvent, temperature, and oxidant. Compared with the previous reported Fe₂O₃ nanoparticles or Au nanoparticles, our nanowires shown higher catalytic abilities and longer stabilities.(2) FePt@Cu nanowires were successfully synthesized via surface deposition of Cu on FePt nanowires. These nanowires were acted as catalysts for epoxidation of trans-1,2-stilbene. Our study revealed that solvent acted as key role in the oxidation process and this oxidation process underwent a solvent involved free-radical oxidation mechanism. FePt@Cu nanowires were very stable and can be recycled for multiple times without activities lose. This is the first time reported the nano-copper catalysts for the double bond epoxidation.(3) Pt NWs with 2nm in diameter was successfully synthesized for alkenes and alkynes hydrogenation. These nanowires show the highest catalytic activities and more than 50% of C = C and C≡C bonds could be reduced to C-C in several minutes. Furthermore, aromatic rings such as aniline and phenol could be reduced at relatively low pressure and temperature while using acetic acid as solvent and aluminum chloride as co-catalyst.(4) Pt nanowires were further used as photocatalysts for photodecomposition of dye waste water.