69076-07-9Relevant articles and documents
Alkyldibenzothiophenes hydrodesulfurization-promoter effect, reactivity, and reaction mechanism
Bataille, Frederic,Lemberton, Jean-Louis,Michaud, Philippe,Perot, Guy,Vrinat, Michel,Lemaire, Marc,Schulz, Emmanuelle,Breysse, Michele,Kasztelan, Slavik
, p. 409 - 422 (2000)
The promoter effect of Co or Ni on the HDS activity of sulfided Mo/alumina was studied using dibenzothiophene (DBT) and 4,6-dimethyldibenzothiophene (46DMDBT) as reactants at 340°C under a 4 MPa total pressure in a fixed-bed microreactor. The promoted and unpromoted catalysts had different characteristics concerning the two main pathways, i.e., direct desulfurization and hydrogenation (HYD), of the HDS of DBT and 46DMDBT. The origin of differences in reactivity of these compounds to steric effects upon adsorption on the catalytic surface lay in the kinetics of transformation of these two compounds. The DDS and HYD pathways could be decomposed into H2 addition steps and C-S bond cleavage by elimination steps. The rate-determining step might be different depending on the reactant and on the catalyst. On the unpromoted catalyst, DBT and 46DMDBT had comparable reactivities because the C-S bond cleavages were rate-limiting for both reactants. On the promoted catalysts, DDS became the main pathway for the HDS of DBT. The HYD of DBT into dihydrodibenzothiophene was the rate-limiting step for the two pathways. With 46DMDBT, the influence of the promoter on C-S bond cleavage was limited due to steric constraints. Thus, C-S bond cleavage remained the rate-limiting step, particularly for the DDS pathway. The presence of the methyl groups in 46DMDBT changed significantly the reactivity concerning the two pathways. The low reactivity of 46DMDBT was due to the inhibition of the DDS pathway. Several explanations were proposed for this lower reactivity. The promoter improved the C-S bond cleavage activity of the MoS2 on alumina catalyst by increasing the basicity of certain sulfur anions shared between the Mo and the promoter, e.g., Ni or Co.
The preparation of Mo/γ-Al2O3 catalysts with controllable size and morphology via adjusting the metal-support interaction and their hydrodesulfurization performance
Yuan, Pei,Cui, Chunsheng,Han, Wei,Bao, Xiaojun
, p. 115 - 125 (2016/07/12)
In this work, a series of Mo/γ-Al2O3 catalysts have been prepared by using Mo species enwrapping with dodecyltrimethylammonium bromide (DTAB) as the novel precursors for the hydrodesulfurization (HDS) of dibenzothiophene (DBT). The objective of this work is to get a deep insight into the effect of the Mo precursors on the size and morphology of the active phases and HDS activity. DTAB as the organic additive for the preparation of Mo precursors can dominate the nature of precursor solution and adjust the metal-support interaction so as to control the dispersion and morphology of the active phases. It is clearly shown that the addition of DTAB can effectively decrease the strong interaction between the Mo species and γ-Al2O3 support and favor to tune the size and morphology of MoS2 nanoparticles. The optimum molar ratio of DTAB/Mo is 3/5 and the corresponding catalyst shows the highest sulfidation degree with the most suitable stacking layer numbers and the shortest length of MoS2 and thus exhibits the best HDS performance. Our work explores the important roles of organic additive to adjust the metal-support interaction and control the morphology of active phases and provides an effective precursor which can be used widely to prepare supported catalysts.
Desulfurization of diesel fuel with nickel boride in situ generated in an ionic liquid
Shu, Chenhua,Sun, Tonghua,Guo, Qingbin,Jia, Jinping,Lou, Ziyang
, p. 3881 - 3889 (2014/08/05)
In order to improve the desulfurization efficiency, an ionic liquid (IL) was used as the solvent for the desulfurization of diesel fuel with nickel boride. The nickel boride prepared in IL-H2O showed high specific surface area. The desulfurization efficiency of model organosulfur compounds in this work was higher than that in the previous studies. The desulfurization reactivity of model organosulfur compounds followed the order of BT (DBT) > 3-MBT > 4,6-DMDBT. Furthermore, the products of model organosulfur compounds after desulfurization were analyzed by GC/MS and their corresponding reaction routes were proposed. The effectiveness of nickel salts followed the order of NiCl2 (Ni(OAc)2) > NiSO4 > Ni(NO 3)2. The desulfurization efficiency of model diesel fuels reached 90.6% under the conditions of B/S molar ratio = 9, Ni(OAc)2/S molar ratio = 3, oil/IL volume ratio = 3, water content in IL = 5%, and reaction time = 50 min. ILs maintained their original structures after regeneration. Finally, the desulfurization of real diesel fuel was carried out and a desulfurization efficiency of 88.6% was obtained in 50 min. This journal is the Partner Organisations 2014.
