二苯并噻吩在CoMo/CNT催化剂表面上的吸附行为研究  

Study of Adsorption Behavior of Dibenzothiophene on the Surface of CoMo/CNT Catalyst

作　　者：商红岩[1] 刘晨光[1] 柴永明[1] 邢金仙[1] 

机构地区：[1]石油大学化学化工学院重质油国家重点实验室中国石油天然气集团公司催化重点实验室,东营257061

出　　处：《化学学报》2004年第9期888-894,M004,共8页Acta Chimica Sinica

基　　金：中国石油股份有限公司CNPC集团公司催化重点实验室资助课题 (No.0 3A50 50 1 0 1 )

摘　　要：用等体积浸渍法分别制备了碳纳米管 (CNT)、活性炭 (AC)、γ Al2 O3 负载的CoMo加氢脱硫催化剂 .用器外预硫化的方法制备了相应的硫化态的CoMo催化剂 .采用程序升温脱附 (TPD)技术表征了载体、负载的氧化态CoMo催化剂和硫化态CoMo催化剂的表面酸性 .采用热重 (TG)和XRD等分析手段研究了二苯并噻吩 (DBT)在碳纳米管载体、碳纳米管负载的氧化态CoMo催化剂以及硫化态CoMo催化剂上的吸附行为 .对DBT在样品表面的吸附行为与表面酸性进行了关联 .研究发现 :DBT分子在载体、负载的催化剂表面的吸附行为遵循如下的规律 :硫化态CoMo催化剂对DBT的吸附能力 >相应氧化态CoMo催化剂对DBT的吸附能力≥相应载体对DBT分子的吸附能力 .研究表明 :载体的比表面积的大小不是决定DBT吸附量的主要因素 .DBT分子的吸附量与载体或催化剂的表面酸性以及其他表面性质有一定的内在联系 ,随着表面酸性的增强 ,吸附量也相应增大 .加氢脱硫产物分布结果表明 ,DBT分子在硫化态CoMo/CNT催化剂的表面可能以端点吸附为主 ;而在硫化态CoMo/AC和CoMo/γ Al2 O3 催化剂上存在两种竞争的吸附态 ,部分DBT分子端点吸附 。Adsorption properties of dibenzothiophene from toluene solution over the CNT, CoMoS/CNT and CoMoO/ CNT were studied. The consecutive desorption of adsorbed DBT molecules was measured by TGA. The AC, CoMoO/ AC, CoMoS/AC, gamma-Al2O3, CoMoO/gamma-Al2O3 and CoMoS/gamma-Al2O3 samples were also subjected to analyses for comparison. The acidic properties of the samples were characterized by using NH3-TPD technique. The relationship between the adsorption properties of DBT and the acidic properties of catalysts was correlated. The experimental results revealed that the adsorption ability of DBT molecules on the surface of various samples follows the trend: sulfide CoMo catalyst > corresponding oxidic CoMo catalyst greater than or equal to corresponding support. It was found that adsorption amount of DBT on the sulfide CoMo catalysts was the greatest among all the oxide state CoMo catalysts, sulfide CoMo catalysts and different supports studied. It was suggested that the size of surface area of samples did have little effect on the adsorption ability to DBT molecules. It was indicated that there is a certain relation between the surface acidic properties of the samples and adsorption ability to DBT. Based on the experimental results it was suggested that almost all the DBT molecules adsorbed on the surface of CoMoS/CNT prefer in an end-on adsorption state. It was also suggested that adsorption of DBT molecules on the surfaces of CoMo/AC and CoMoS/gamma-Al2O3 may include two states, one is the end on manner through the adsorption sulfur atom and the other is the flat manner through the adsorption of pi electrons of DBT molecules.

关 键 词：等体积浸渍法 碳纳米管负载钴钼催化剂 器外预硫化 程序升温脱附 吸附 加氢脱硫 碳纳米管 热重分析 二苯并噻吩 柴油 

分 类 号：O643.3[理学—物理化学]