| More and more attentions on the hydrogenation of C9 petroleum resin have been attracted in recent years. At present the research of petroleum resin hydrogenation is mainly focused on the hydrogenation of C5 petroleum resin. The hydrogenation technology of petroleum resin in abroad has been used in industry, however, the studies on petroleum resin hydrogenation is still in stage of laboratory domestically. Therefore, it is urgent to develop catalytic hydrogenation technology of C9 petroleum resin. In this study, three types of commercialγ-Al2O3 were used as support of Pd catalysts. And the effects of structural properties ofγ-Al2O3, surface acid properties and active metal components of Pd/γ-Al2O3 catalysts on the catalytic activity and stability for the C9 petroleum resin hydrogenation were investigated, and theγ-Al2O3 supports and supported Pd catalysts were characterized in detail by N2 adsorption, CO chemisorption, XRD (X-ray diffraction), SEM (Scanning Electron Microscope), TEM (transmission electron microscopy), NH3-TPD (temperature-programmed desorption) techniques. The experimental results indicated that pore size of supported hydrogenation catalysts is of an significant influence on the catalytic hydrogenation of C9 petroleum resin. And the adequate macro-pores of catalyst is favorable to increase the catalytic activity and stability in catalytic hydrogenation of macromolecule. The pores ofγ-Al2O3 (W251) are majorly distributed in the range of macroprous size, which is favor to palladium precursor easily accessed to macroprous interior, it consequently promoted Pd dispersion and formed "egg white" catalysts.Furthermore, the deactivation of Pd/γ-Al2O3 catalysts in hydrogenation of C9 petroleum resin could be attributed to the carbon deposition and sulfur poisoning. Mg-modifiedγ-Al2O3 support has stable magnesia alumina spinel (MgAl2O4 structure at matricesγ-Al2O3 surface layer, it is demonstrated that the existence of MgAl2O4 spinel can decrease total amount of both strong acid sites and weak acid sites remarkably. It is extraordinary avail for preventing catalyst carbon deposit. At the sane time, PdPt bi-component catalyst also enhanced the resistance to sulfur poisoning. |
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