有机添加物对活性相形貌调控及原生积炭对加氢脱硫活性的影响

Control of Active Phase Morphology by Organic Additives and Effects of Protogenesis Carbon Deposits on Hydrodesulfurization Activity

为了探究有机添加物对活性相形貌调控以及原生积炭对加氢脱硫活性的影响,通过在浸渍液中引入具有不同官能团的有机物制备了相应的Mo/Al2O3催化剂,并采用拉曼、N2吸附-脱附、透射电镜、X射线光电子能谱和程序升温氧化-质谱等手段对催化剂进行表征。结果发现:与未引入有机物的样品相比,引入有机物在一定程度上减弱了钼物种与氧化铝表面的相互作用,从而促进钼物种的硫化;而且引入具有不同官能团的有机物对MoS2片晶生长可起到“模板导向”和“空间限制”的作用,实现了对MoS 2形貌结构的调变。其中,引入十六烷基三甲基溴化铵不仅显著提高了钼的硫化度,诱导形成具有合适尺寸和层数的MoS2片晶,而且形成的“毗邻”活性相的炭物种最少,从而有利于改善4,6-二甲基二苯并噻吩与活性中心的可接近性并提高加氢脱硫活性。

To study the morphology control of active phase by organic additives and effects of protogenesis carbon deposits on hydrodesulfurization activity,organic additives with different functional groups were introduced into the impregnating solution during the Mo/Al2O3 preparation processing.The catalysts were characterized by laser Raman spectroscopy(LRS),N 2 physisorption,transmission electron microscopy(TEM),X-ray photoelectron spectroscopy(XPS)and temperature-programmed oxidation(TPO)-MASS,etc.The characterization results show that compared with the reference samples without organic additives,the addition of organic additives partly weakens the interaction between Mo species and alumina surface,this promoting their sulfidation performance.Moreover,the addition of organic additives with different functional groups plays important roles in the formation of MoS2 via their template-directed and space-confined effect,for realizing the morphology control of MoS2 slabs.Promisingly,the catalyst modified by hexadecyl trimethyl ammonium bromide(CTAB)exhibits the best hydrodesulfurization activity,due to the highest degree of Mo sulfidation,the least carbon deposits in the vicinity of active phase and the easiest accessibility of 4,6-dimethyldibenzothiophene to the active sites.