Study On The Preparation Of γ-Al₂O₃ Nanoparticles And The Catalytic Performance Of Supported Ag-Cu Bimetallic Catalysts

As the improvement of industrial technology, the support quality is growing important for the performance of catalyst. Therefore, it is very important to prepare evenly dispersedγ-Al2O3 nanomaterial with special morphologies, small and appropriate pore size distribution through different methods in industry. In recent years, the preparation of nano-load IB group metal composite catalysts supported onγ-Al2O3 has attracted a great deal of attention from scientists.Herein, we prepared nanofibers (<5nm) of pseudo-boehmite (PB) with a high surface area (327.6m2/g) using AOT micelle solution template method. A hexagonal ring precursor of alumina and nanofibers ofγ-Al2O3 (the diameter is less than 10nm) were prepared by lamellar liquid crystal method and microemulsion template method respectively.Then, we selected microemulsion template method to prepare Ag-Cu/γ-Al2O3 complex catalysts. A series of Ag/Cu bimetallic nanoparticles at various molar ratios in reticulate-like y-Alumina were synthesized. XPS analysis showed that there was a strong interaction between Ag and Cu that made both Ag and Cu more likely to lose electrons. The catalytic performances of catalysts were tested by styrene epoxidation. The results showed that the styrene oxide selectivity could reach 76.6% at Ag/Cu molar ratio of 3/1, while the maximum conversion (up to 94.6%) appeared at Ag/Cu molar ratio of 1/1. The possible mechanism of the reaction:the O2- adsorbed on the silver surface can migrate to the copper surface and react with the adsorbed styrene easily.