Tuning Al₂O₃Surface With SnO₂Via Monolayer Dispersion Method To Prepare Improved Supports For Pd

γ-Al2O3, with a large specific surface area and stable crystal structure, is widely used as a rigid support in the industrial field. SnO2is a semiconductor material with a small specific area but abundant active lattice and surface active oxygen species, which has a potential application in catalysis field. In this work, the surface properties of γ-Al2O3was modified with SnO2via monolayer dispersion method, with the expectation to prepare novel supports with both active oxygen species and improved thermal stability and surface areas. The catalytic performance of the composite oxides was studied.Part Ⅰ, A series of SnO2/γ-Al2O3with various SnO2loadings on γ-Al2O3support were prepared by a deposition-precipitation method. The catalysts were characterized by N2-BET, H2-TPR, XRD and XPS techniques. With XRD extrapolation method, the monolayer dispersion capacity of SnO2on γ-Al2O3was found to be0.172mmol/100m2. CO Oxidation was used as a probing reaction to investigate the catalytic performance of SnO2/γ-Al2O3. The results show that the catalytic activity of CO oxidation increased with the increase of SnO2loading. Supported Pd catalysts were prepared by impregnation method, using the SnO2/γ-Al2O3as supports, and their catalytic activities for CO oxidation were also investigated.Part Ⅱ, the SnO2/γ-Al2O3support, with SnO2in monolayer dispersion capacity, was chosen to further modified with La、Ce、Y by the deposition-precipitation method. XRD, N2-BET, H2-TPR were used to explore the physical and chemical properties of the catalysts. The results show that the Ce-modified SnO2/γ-Al2O3catalyst exhibited the best performance, and its activity is close to pure SnO2at high-temperature region. Afterward, the impregnation method was used to prepare supported Pd catalyst with the above-mentioned supports. The catalytic activity of the catalysts were characterized by CO oxidation and CH4oxidation reactions.