The Impact Of The Synergistic Effect On The Material Structure And Properties And Application Research On The Field Of Catalysis

The synergistic effect on the performance of materials has been intensely studied.This thesis developed a butyllithium co-reduction method and a one-pot method tosynthesize two kinds of new materials, and studied the synergistic effect on thecatalytic performance of the obtained materials.This work have successfully synthesized size-controllable bimetallic nanoparticlesof Au3M (M=Ni, Co, Fe) using butyllithium as reducing agents and oleylamine asprotecting agents, and used Au3M nanoparticles as precursors to prepare oxides supportedAu-MxOy/SiO2heteroaggragate nanocatalysts. The influence of pretreatment conditions onthe structure of Au-MxOy/SiO2and the influence of the structure on the catalytichydrogenation of p-nitrophenol were investigated. The relevant characterizations forAu3M alloy nanoparticles, Au-MxOy/SiO2and Au/SiO2catalysts, such as XRD, XPS,TEM, FT-IR and UV-vis, were conducted. The results showed that compared to thecontrol Au/SiO2, the Au-MxOy/SiO2catalysts illustrated better thermal stability andsignificantly higher catalytic activity for p-nitrophenol hydrogenation reaction thanAu/SiO2. This work revealed that the improvement of thermodynamic stability andcatalytic performance is due to the formation of Au-MxOyheteroaggregate with strongmetal-oxides interaction by in situ phase transformation of Au3M alloy nanopartilces.This work employed a one-pot method to successfully synthesizemolybdenum-doped mesoporous SBA-15(Mo-SBA-15), mesoporous silica supportedMoO3/SBA-15, and traditional silica supported MoO3/SiO2catalysts, and studied theircatalytic performance for metathesis reaction of1-butene and ethene to propene. Theobtained materials were comprehensively characterized by XRD, TEM, BET, UV-DRS,Raman, XPS and IR. For Mo-SBA-15catalysts, the well-ordered mesoporous structure of SBA-15was maintained in the Mo-SBA-15, and Mo species were highly dispersed andincorporated into framework with high concentration of Mo5+species. The mesoporoussilica supported MoO3/SBA-15showed a significant reduction of BET surface area due tothe deposition of MoO3nanoparticles into the channels of SBA-15and the traditionalsilica supported MoO3/SiO2catalysts also showed the lowest BET surface area, and theMo6+species was only observed in both of them. The catalytic studies for metathesisreaction revealed that the doped Mo-SBA-15illustrated a superior performance to thesupported MoO3/SBA-15catalysts as well as the supported MoO3/SiO2catalysts. Theorigin of catalytic performance enhancement for Mo-SBA-15was assigned to theincorporation of Mo species into SBA-15framework. This study demonstrated theinfluence of the catalytic synergetic effect on catalytic performance and was helpful todesign metathesis catalysts.