Synthesis And Catalytic Properties Of Platinum-based Nanoalloy

Noble metals were high-profile because of their excellent physical chemical properties performed in optical,mechanical,magnetic,electrical,catalytic and sensing fields.However,the large-scale application of noble metal nanomaterials were largely limited owing to the restriction of their nature as well as their rare storages.Therefore,it's hopeful to find a strategy improving performance of noble metal nanomaterials,at the same time reducing their dosage.In recent years research shows that alloyed with other metals,control-synthesis the specific size,composition,morphology and structure of metal nano materials could change physical and chemical properties such as light,electricity,magnetic,catalytic and mechanical significantly.Therefore,the deeper study for the size,composition,morphology and architectural control-synthesis of noble metal alloy nanomaterials has been carried out.The interaction of different metal atoms in the alloy produces a specific surface active center or electronic structure.Because of the synergistic effect,alloy nano materials exhibit physicochemical properties that are unique and often superior to nano materials comprised of the individual metals,and nobal metals and non noble metal alloed could reduced the usage amount of noble metals to lower the costs,which is consistent with the trend that industrial production to reduce the quantity of noble metal utilization.As catalysts for heterogeneous reactions,the noble metal nanomaterial exhibited outstanding performance in stability and recycling as well as consistent with the concept of green chemistry.However,there are still challenges in the application of noble metal alloy nano materials.The synthesis process is inconvenient,the control-synthesis is difficult to achieve the repeatability,the catalytic mechanism is not clear,and so on.In this paper,based on the previous studies,we have synthesized the alloy nano materials based on the noble metal Pt,and made some research on the composition,size,morphology and catalytic activity:1.AuPt alloy nanoparticles(NPs)were facilely synthesized with oleylamine as the stabilizing ligand and characterized by high-resolution transmission electron microscopy,powder X-ray diffraction,inductively coupled plasma-atomic emission spectrometer analysis,and so on.In addition,the AuPt alloys supported by the nano CeO2 exhibit high selectivity and efficiency in hydrogenation of benzylidene acetone under ambient temperature and pressure.By analyzing the catalytic performance over the NPs with different Au:Pt compositions,we found that the TONPt values(based on the number of Pt atoms)vary in the same trend with the change of conversion.Despite that gold itself shows no catalytic activity,the improved conversion and TONPt with the alloy catalysts clearly show the promotion effect of gold on the catalytic activity of the platinum.The inactive metal significantly improves the catalytic activity of active metal,which shows that the AuPt alloy exhibits an interesting synergistic effect.2.Pt alloy nano materials have been widely used in catalysis because of their excellent properties.In this paper,high temperature synthesized the PtCu alloy nanoparticles used oil amine as standing ligands and reducing agent with nitrogen atmosphere,then stirring at room temperature,oxide the copper exposed on the alloy surface to copper ions by the oxygen in the air,PtCu alloy material has been nano flower shape.The results show that PtCu alloy has a uniform size and morphology,and exhibits good catalytic activity and selectivity in catalytic hydrogenation of unsaturated carbonyl compounds.