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Mijoin, Jérôme; Pérot, G.; Bataille, F.; Lemberton, J.L.; Breysse, M.; Kasztelan, S.

doi:10.1023/a:1009055205076

Cited by 56 publications

(30 citation statements)

References 12 publications

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“…As previously mentioned, HYD is a thermodynamically un-favored reaction route [8]. Consequently, only those catalysts in which DBT desulfurization is kinetically controlled, for example un-promoted MoS 2 and Pd, HYD reaction rates have been reported to be comparable to DDS ones [4,19]. On the other hand, it must be remarked that the total nominal metallic content of all Pd-Pt catalysts is 2 wt% which is far from those contents reported by Kabe et al [10].…”

Section: Catalytic Testsmentioning

confidence: 99%

“…alkyl-dibenzothiophenes substituted in 4-and 6-positions such as 4,6-dimethyldibenzothiophene (4,6-DMDBT)) [1][2][3]. In spite of the large amount of reports claiming new more active CoMo and NiMo sulfided catalysts, none of them have proven preferential conversion of DBT via HYD so far [1][2][3][4][5][6]. This is due to the fact that the role of Co and Ni as promoters is mainly to enhance the direct C-S bond scission function of the MoS 2 active phase [4].…”

Section: Introductionmentioning

confidence: 99%

“…In spite of the large amount of reports claiming new more active CoMo and NiMo sulfided catalysts, none of them have proven preferential conversion of DBT via HYD so far [1][2][3][4][5][6]. This is due to the fact that the role of Co and Ni as promoters is mainly to enhance the direct C-S bond scission function of the MoS 2 active phase [4]. Also, to increase the selectivity to HYD over the direct desulfurization route (DDS), the active phase of the catalyst should be able to selectively adsorb the DBT molecule in a flat p-mode through one of its aromatic rings and perform its HYD rather than binding and breaking the S heteroatom in a ''single'' step [7].…”

Section: Introductionmentioning

confidence: 99%

“…Consequently, comparing 4,6-DMDBT and DBT, only the latter allows a direct measurement of the intrinsic catalytic selectivity of the tested material either to HYD or to DDS. It is important to recall that both DBT and 4,6-DMDBT share a common mechanistic dynamics comprising parallel HYD and/or DDS reaction routes when their HDS is performed over ''non-strongly'' acidic supported catalysts [1][2][3][4]. This is why in this work DBT was chosen as a more suitable model molecule than 4,6-DMDBT to develop highly HYD selective catalysts.…”

Section: Introductionmentioning

confidence: 99%

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Highly HYD Selective Pd–Pt/support Hydrotreating Catalysts for the High Pressure Desulfurization of DBT Type Molecules

2009

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A silica-alumina supported Pd-Pt bimetallic catalyst was found to be highly active in dibenzothiophene hydrodesulfurization with preferential selectivity to the hydrogenation (HYD) route of desulfurization at the expense of the direct removal of sulfur. In addition, it was demonstrated that for Pd-Pt catalysts selectivity to HYD can be drastically changed by a ''soft'' change in the nature of the carrier.

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Section: Catalytic Testsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Highly HYD Selective Pd–Pt/support Hydrotreating Catalysts for the High Pressure Desulfurization of DBT Type Molecules

2009

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“…C-S bond cleavage may occur by elimination as well as by homolytic C-S bond scission (hydrogenolysis), as demonstrated in the HDS of alkanethiols [1][2][3] and aromatic thiols such as benzothiophene and dibenzothiophene [4,5]. C-S hydrogenolysis has also been observed in the homogeneous reaction of aliphatic and aromatic thiols to hydrocarbons with the Cp¢ 2 Mo 2 Co 2 S 3 (CO) 4 cluster [6].…”

Section: Introductionmentioning

confidence: 97%

Mechanism of the hydrodenitrogenation of neopentylamine and adamantylamine on sulfided NiMo/Al2O3

et al. 2006

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Neopentanethiol, 1-adamantanethiol, and 2-adamantanethiol were primary products and neopentane and adamantane were secondary products in the hydrodenitrogenation of neopentylamine, 1-adamantylamine, and 2-adamantylamine, respectively, over sulfided NiMo/Al 2 O 3 . Dialkylamines and dialkylimines were formed as primary products in the reactions of 2-adamantylamine and neopentylamine as well. None of the three amines can react by ammonia elimination and a classic S N 2 substitution of the NH 2 group by H 2 S is not possible for the adamantylamines either. The formation of di(2-adamantyl)imine and di(neopentyl)imine indicates that dehydrogenation and hydrogenation reactions occur and that imine or iminium-cation intermediates play an important role. NH 2 -SH substitution takes place by dehydrogenation of the amine to an imine or iminium cation, which adds H 2 S and eliminates NH 3 . The secondary character of adamantane and neopentane demonstrates that hydrogenolysis of the aliphatic C-N bond does not take place over sulfided NiMo/Al 2 O 3 below 340°C. Even though 1-adamantylamine can neither react by classic S N 2, E1, and E2 reactions, nor via an imine or iminium cation, it formed 1-adamanethiol at 300°C. This reaction might take place by an S N 1 reaction or by adsorption of the amine at a surface vacancy, followed by a shift of the adamantyl group to a neighboring sulfur atom.

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Deep HDS of Diesel Fuel: Inhibiting Effect of Nitrogen Compounds on the Transformation of the Refractory 4,6-Dimethyldibenzothiophene Over a NiMoP/Al2O3 Catalyst

Rabarihoela-Rakotovao

Diehl

Brunet

2008

Catal Lett

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The effect of nitrogen-containing compounds (acridine and 1,4-dimethylcarbazole: 14DMCARB) on the hydrodesulfurization of 4,6-dimethyldibenzothiophene (46DMDBT) was studied on a sulfided NiMoP/Al 2 O 3 catalyst in a fixed bed microreactor (340°C, 40 bar). Both nitrogen-containing compounds inhibited the hydrodesulfurization of 46DMDBT. However, the effect of acridine (a basic compound) and mainly its hydrogenated product (presumably 1,2,3,4,5,6,7,8-octahydroacridine: OHA1) was much more significant than the effect of 14DMCARB (a non-basic compound). In the presence of acridine, the socalled direct desulfurization pathway (DDS) of the HDS of 46DMDBT was less affected than the hydrogenation pathway (HYD) and was even slightly promoted when the partial pressure of acridine increased (after a strong initial inhibition). This was ascribed to a cocatalytic contribution of the nitrogen-containing compound to the C-S bond cleavage. 14DMCARB had the same inhibiting effect on both pathways (DDS and HYD). We also demonstrated that acridine inhibited the transformation of 14DMCARB and can explain why carbazoles are generally the main nitrogen impurities present in gasole after hydrotreatment.

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Untitled

Cited by 56 publications

References 12 publications

Highly HYD Selective Pd–Pt/support Hydrotreating Catalysts for the High Pressure Desulfurization of DBT Type Molecules

Highly HYD Selective Pd–Pt/support Hydrotreating Catalysts for the High Pressure Desulfurization of DBT Type Molecules

Mechanism of the hydrodenitrogenation of neopentylamine and adamantylamine on sulfided NiMo/Al2O3

Deep HDS of Diesel Fuel: Inhibiting Effect of Nitrogen Compounds on the Transformation of the Refractory 4,6-Dimethyldibenzothiophene Over a NiMoP/Al2O3 Catalyst

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