Preparation, Characterization And Catalytic Application Of Pd Catalysts In Hydrogenation Of C5 Petroleum Resin

Hydrogenation of C5 petroleum resin is the arisen innovation of foreign country in recent years. This process begins with in 1970s at overseas and just breaks away in inland. All of catalysts in c5 petroleum resin hydrogenation are dependence on import in our country. So, it is very necessary to develop this catalyst which its performance same as catalysts of import. The main progress and research results have been obtained as follows:1. Preparation, characterization and catalytic application of Pd catalysts in hydrogen -nation of C5 petroleum resin.A series of catalysts were prepared using noble metal Pd as active constituent andγ-Al₂O₃ as underlying carrier by impregnating-co precipitation meas. By Comparison to abroad catalysts, catalyst Pd/ MgAl₂O₄—γ-Al₂O₃ has higher activation and stability in hydrogenation of C5 petroleum resin. The effects of supports, preparation condition and addition on the catalytic performance of C5 petroleum resin hydrogenation were studied. The catalysts of Pd/MgAl₂O₄—γ-Al₂O₃å’ŒPd/γ-Al₂O₃ were characterized in detail by XRD, SEM, EDS,TPD, BET, FT-IR techniques. The main conclusions obtained are listed as follow:â‘ Compared with foreign catalyst, Pd catalyst supported Mg-modifiedγ-Al₂O₃ that we prepared had better catalytic activity and the thermal stability for C5 petroleum resin hydrogenation.â‘¡The preparation condition of Pd/MgAl₂O₄—γ-Al₂O₃ catalyst obtained are listed as follow:Precipitant: 5%NaOH;PH of the predecessor solution: 4～5;Firing condition: 500℃, 2h;Reduction mode: hydrogen gas reduction;Reduction condition: 300℃, 3h.â‘¢he morphology and surface structure of MgAl₂O₄—γ-Al₂O₃ carrier andγ-Al₂O₃ were characterized by XRD, SEM and N₂ adsorption/desorption. According to the experimental result, at matricesγ-Al₂O₃ surface layer they form stable magnesia alumina spinel (MgAl₂O₄) structure. We also observe the addition of Mg intoγ-alumina leading to a "gully-like" surface morphology. This surface texture not only enlarged the average pore diameter, but also helped to anchor the Pd active phase by incipient wetness impregnation. This larger pore diameter structure of "gully-like" contributes to hydrogenation of C5 petroleum resin macromolecule.â‘£Surface acid properties of Pd/MgAl₂O₄—γ-Al₂O₃ were characterized by NH₃-TPD mean. It is demonstrated that the use of MgAl₂O₄ spinel can decrease remarkablely total amount of both strong acid sites and weak acid sites. It is extraordinary avail for preventing catalyst carbon deposit.⑤d/MgAl₂O₄—γ-Al₂O₃ catalyst was characterized by EDS technique. It is demonstrated that Pd dispersion degree is very high. We also find distribution trend of Pd like Mg's, conclude Pd mostly dispersed over MgAl₂O₄, instead of matricesγ-Al₂O₃.2. Conceptual analysis of catalysts deactivationThe morphology, surface structure and other properties of import catalysts of fresh and F601 were characterized by XRD, SEM, ICP, FT-IR and BET techniques. According to the experimental result, it is demonstrated that surface sintering, carbon formation and Pd bleeding were major factors for deactivation of C5 petroleum resin hydrogenation catalyst.