论文部分内容阅读
选择四种不同配位基团的双齿配位分子乙二胺(EN)、乙醇胺(EA)、乙二醇(EG)和丙二酸(MA)对CoMo/γ-Al_2O_3催化剂改性,比较了它们对二苯并噻吩HDS性能的影响。结果表明,其活性顺序为CoMo(EN)>CoMo(EA)>CoMo(EG)≈CoMo(MA)>CoMo,反应以直接脱硫路径为主,随反应温度升高,加氢路径的占比增加,加入配合物后可以促进加氢路径脱硫,CoMo(EN)催化剂具有最高的加氢活性。采用UV-vis、EA、XPS和HRTEM等手段对催化剂进行表征,结果表明,-NH_2与Co~(2+)有强络合作用,-COOH主要是静电作用,而-OH与钴离子没有相互作用。配位基团和Co~(2+)的相互作用,与HDS活性直接相关。配合物与Co~(2+)的结合可以有效生成Co-Mo-S活性相,且配合物碳化减弱载体与活性相的相互作用,有利于生成有更高本征活性的II型活性相。
The bidentate ligands of four different coordination groups, ethylenediamine (EN), ethanolamine (EA), ethylene glycol (EG) and malonic acid (MA) were selected to modify and compare CoMo / γ-Al_2O_3 catalysts Their impact on dibenzothiophene HDS performance. The results showed that the order of the activity was CoMo (EN)> CoMo (EA)> CoMo (EG) ≈CoMo (MA)> CoMo. The reaction was mainly direct desulfurization. , Adding the complex can promote the hydrogenation path desulfurization, CoMo (EN) catalyst has the highest hydrogenation activity. The catalysts were characterized by means of UV-vis, EA, XPS and HRTEM. The results showed that -NH_2 and Co 2+ strongly interacted with each other, -COOH was mainly electrostatic, but -OH and cobalt did not interact with each other effect. The interaction between coordination group and Co ~ (2+) is directly related to the activity of HDS. The Co-Mo-S active phase can be effectively formed by the combination of the complex and Co 2+, and the carbonation of the complex decreases the interaction between the carrier and the active phase, which is favorable for the formation of the type II active phase with higher intrinsic activity.