HDS activity of carbon-supported Ni–Mo catalysts derived from thiomolybdate complexes

Brito, Joaquı́n L.; Severino, F.; Delgado, N. Ninoska; Laine, J.

doi:10.1016/s0926-860x(98)00179-3

Cited by 32 publications

(15 citation statements)

References 22 publications

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“…To explain this result one should therefore consider the different behavior of the two precursors during the thermal decomposition reaction. It was suggested that intermediately formed MoS 3 plays an important role in the formation of the active catalyst supported on so-called activated-carbon [32]. It is well-established that the thermal decomposition of ATM proceeds via intermediately formed MoS 3 , whereas TMATM is decomposed directly to a carbon containing [12]; k CoMo/Al 2 O 3 from reference [22] Preparation and Characterization of SBA-15 Supported Cobalt-Molybdenum Sulfide Catalysts for HDS Reaction 31 Mo sulfide [16].…”

Section: Discussionmentioning

confidence: 99%

Preparation and Characterization of SBA-15 Supported Cobalt–Molybdenum Sulfide Catalysts for HDS Reaction: An All Sulfide Route to Hydrodesulfurization Catalysts

et al. 2008

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MoS 2 hydrodesulfurization (HDS) catalysts promoted with Co supported on SBA-15 were synthesized from sulfur-containing Mo sources [ammonium thiomolybdate (ATM), and tetramethylammonium thiomolybdate (TMATM)] and Co complexes cobalt dimethylthiocarbamate by using different synthesis strategies in order to achieve active catalysts. The (Co)-MoS 2 /SBA-15 catalysts were characterized with X-ray diffraction, N 2 -physisorption and High-Resolution Transmission Electron Microscopy. The catalytic performance in the HDS reaction of dibenzothiophene was examined at T = 623 K and P H2 = 3.4 MPa. The results of the experiments suggest that the sequence of impregnation steps has no significant influence on the HDS activity. On the other hand, the use of different thiomolybdate precursors significantly affects the catalytic activity. The catalysts derived from TMATM show lower HDS activities compared to the catalysts synthesized from ATM which is probably due to the presence of pronounced pore blocking as well as the generation of big needle-like aggregates of the Co-MoS 2 phase. It seems that the formation of intermediate MoS 3 is not a prerequisite for the generation of catalytic active CoMoS phases. The high activity and high selectivity for the direct desulfurization pathway of catalysts prepared with ATM despite the large MoS 2 stacking could be due to the generation of a large number of coordinately unsaturated sites.

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Section: Discussionmentioning

confidence: 99%

Preparation and Characterization of SBA-15 Supported Cobalt–Molybdenum Sulfide Catalysts for HDS Reaction: An All Sulfide Route to Hydrodesulfurization Catalysts

et al. 2008

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“…Table 3 and Figure 1 show that the oxidized spent catalyst was almost completely dissolved in HCl after 3 h at 70 o C despite the insolubility of WO 3 in acids. 13,14 The insoluble fraction contains mainly phosphorus ( Taking into account the composition of the oxidized spent catalyst ( Table 1) the amount of phosphorus is much greater than that necessary to react with WO 3 . H 2 SO 4 was a poorer leachant than HCl ( Figure 1, Table 3).…”

Section: Alkaline Fusion and Acidic Leachingmentioning

confidence: 99%

“…Nickel phosphate is more insoluble in water than its hydroxide, whereas iron phosphate is more soluble than its hydroxide. 28,29 Aluminum (Al(OH) 4 -) was precipitated as Al(OH) 3 after adjusting pH to 6.5-7 by adding 2 mol L -1 HCl. The precipitate was filtered and washed with 0.01 mol L -1 NH 4 OH (4 mL g -1…”

Section: Processing Of Acidic Leachatementioning

confidence: 99%

“…Samples were almost fully dissolved but tungsten was present as PW 12 O 40 3-ions. Processing of the acidic leachate allowed recovery of tungsten (APT) and nickel (Ni 3 (PO 4 ) 2 ), whereas aluminum was precipitated as Al(OH) 3 with minor amounts of AlPO 4 and iron. Processing of the alkaline leachate allowed recovery of tungsten by LLE without the presence of phosphorus but the latter and magnesium were co-precipitated with aluminum.…”

Section: Processing Of Acidic Leachatementioning

confidence: 99%

“…1 The most familiar HDT catalysts are CoMo, NiMo and NiW supported on alumina (Al 2 O 3 ), normally modified by additives that improve activity towards some HDT reactions (such as hydrogenation, cracking) or thermal resistance during its lifetime. [1][2][3][4][5] The increasing severity of environmental directives has prompted the development of a new generation of more efficient catalysts and the proposal of less drastic HDT conditions concerning energy and hydrogen consumption. [2][3][4] The amount of spent non-reusable HDT catalysts has increased markedly in recent years 1 due to a steady increase in the processing of heavier feedstocks in the petroleum refining industries.…”

Section: Introductionmentioning

confidence: 99%

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Processing of spent NiW/Al2O3 catalysts

Paulino¹,

Afonso²,

Cunha³

2013

Quím. Nova

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Recebido em 10/5/12; aceito em 26/11/12; publicado na web em 4/4/13 Spent oxidized (500 o C, 5 h) commercial NiW/Al 2 O 3 catalysts were processed using two different routes: a) fusion with NaOH (650 o C, 1 h), the roasted mass was leached in water; b) leaching with HCl or H 2 SO 4 (70 o C, 1-3 h). HCl was the best leachant. In both routes, soluble tungsten was extracted at pH 1 with Alamine 336 (10 vol.% in kerosene) and stripped with 2 mol L -1 NH 4 OH (25 o C, one stage, aqueous/organic ratio = 1 v/v). Tungsten was isolated as ammonium paratungstate at very high yield (> 97.5%). The elements were better separated using the acidic route.

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SBA-15 as Support for MoS2 and Co-MoS2 Catalysts Derived from Thiomolybdate Complexes in the Reaction of HDS of DBT

et al. 2007

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Molybdenum sulfide and cobalt-molybdenum sulfide catalysts supported on mesoporous SBA-15 were prepared by thermal decomposition of ammonium thiomolybdate (ATM). SBA-15 was synthesized at 353 K and 413 K to obtain pore diameters of about 6 and 9 nm, respectively. The (Co)-MoS 2 /SBA-15 catalysts were characterized with X-ray diffraction (XRD), N 2 -physisorption and high-resolution transmission electron microscopy (HRTEM). HRTEM images give evidence for the presence of a poorly dispersed MoS 2 phase with long MoS 2 slabs and a pronounced MoS 2 stacking. The catalytic performance in the hydrodesulfurization (HDS) reaction of dibenzothiophene (DBT) was examined at T = 623 K and P = 3.4 MPa. The Co-MoS 2 /SBA-15 materials show a relatively high catalytic activity with a strong preference for the direct desulfurization (DDS) pathway. This is an interesting result in view of the significant stacking of MoS 2 particles and the size of the slabs. The generation of the catalytically active CoMoS phase and a large number of coordinately unsaturated sites (CUS) may explain the high performance of Co promoted MoS 2 /SBA-15 catalysts in the HDS reaction.A confinement effect of the mesoporous channels of SBA-15 is observed for the unpromoted MoS 2 /SBA-15 catalysts. SBA-15 with 9 nm channel diameter with 11 wt.% Mo loading shows a higher selectivity for the hydrogenation pathway than SBA-15 with 6 nm channel and 16 wt.% Mo loading.

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HDS activity of carbon-supported Ni–Mo catalysts derived from thiomolybdate complexes

Cited by 32 publications

References 22 publications

Preparation and Characterization of SBA-15 Supported Cobalt–Molybdenum Sulfide Catalysts for HDS Reaction: An All Sulfide Route to Hydrodesulfurization Catalysts

Preparation and Characterization of SBA-15 Supported Cobalt–Molybdenum Sulfide Catalysts for HDS Reaction: An All Sulfide Route to Hydrodesulfurization Catalysts

Processing of spent NiW/Al2O3 catalysts

SBA-15 as Support for MoS2 and Co-MoS2 Catalysts Derived from Thiomolybdate Complexes in the Reaction of HDS of DBT

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