Structural Design,Preparation And Catalytic Application Of Ruthenium-Based Nanomaterials

Volatile organic compounds(VOCs)as an important resource of atmospheric pollution have a significant influence on the development of society and human health at present.In order to eliminate the pollution from VOCs,the most common way is to decompose them into CO2 and H2O by suitable catalysts.Hence,it has a vital importance to design and prepare highly efficient catalysts for the oxidation of VOCs.The relatively cheap metal Ru reduces the manufacturing cost of the catalyst in comparison with those of the traditional precious Pt and Pd catalyst.Owing to highly catalytic properties for the oxidation of VOCs over those of non-noble metal catalysts,Ru-based catalysts have become a hot research topic in the field.It is well known that the structure of the catalysts has a significant effect on their catalytic properties,therefore,tailoring of the structure is considered to be a key method for the improvement of their catalytic properties.In this thesis,the core-shell Ag-Ru nanoparticles with an Ag core and a Ru shell have been synthesized via "seed-mediated growth",then Ru nanoparticles with hollow interior were also gained based on the etching of Ag nanoparticles.Finally,core-shell Ag-Ru/Al2O3 and hollow Ru/Al2O3 were prepared by impregnation method.For the oxidation of benzene,both of the core-shell Ag-Ru and hollow Ru show enhanced catalytic activity,owing to the synergistic effect between Ag and Ru as well as large surface area of hollow structure.It should be noted that core-shell Ag-Ru nanoparticles exhibited the highest catalytic activity.In addition,in order to investigate the interaction between active metal and support,the CeO2 was used as the support to gain Ru/CeO2 catalyst system.Compared with Ru/Al2O3 catalyst system,Ru/CeO2 catalysts show higher catalytic activities for the oxidation of benzene,which should be attributed to the interaction between Ru metal and CeO2 support.Considering the enhanced effect between metal and support,we synthesized a series of CeO2 with different morphologies as support to expect the obatenment of more highly efficient catalytic.In the end,the core-shell Ag-Ru nanoparticles were loaded on different support.The influence of the kinds of support on the diffusion of Ag core in core-shell Ag-Ru nanoparticles was discovered through the observation of the outward diffusing rate of Ag core.