Preparation of layer structure-controlled Ru-Sn-Al2O3 catalysts and their reactivity

In order to achieve functional group selective hydrogenation, the layer str ucture of Ru-Sn-Al2O3 catalysts was controlled by using sol-gel, powder imp regnation and combined sol-gel impregnation methods. The properties of the catalysts and effectiveness in hydrogenation of dimethyl terephthalate were examined. The surface Sn contents of the catalysts characterized by X-ray photoelectron spectroscopy depended on the preparation method, in spite of almost the same bulk Ru and Sn compositions measured by X-ray fluorescence analyses. TPR and CO adsorption of the catalysts also depended on the prepa ration method. With regard to the conversion rate of dimethyl terephthalate and the rate of product conversion from methyl 4-hydroxy methylbenzoate to p-xylene via methyl p-toluate, Ru impregnation catalysts had higher rates than the other catalysts.