FIELD OF THE INVENTION

5 The instant invention concerns a bulk catalyst precursor and a method for obtaining it. More particularly it concerns the field of hydrodesulfuration.

PRIOR ART

The environmental regulations are becoming increasingly stringent. Significant 10 reductions in the sulfur content of transportation fuels are going to be required. For example, by the end of this decade, maximum sulfur levels for distillate fuel will be limited to 10 wppm in Europe and Japan and 15 wppm in North America.

To meet these ultra-low sulfur requirements without expensive modifications to existing refineries, it is necessary to design new catalysts having increased 15 properties, in particular very high activity for desulfurization, more particularly for distillate fuels at low to medium pressure.

Supported bimetallic nickel tungsten catalysts and their use in hydrotreatment of hydrocarbon feedstock are long known in the art. GB 820536 describes a process for the manufacture of mechanically strong supported catalyst particles comprising 20 combinations of cobalt, nickel, molybdenum, vanadium or tungsten in which a spray- dried alumina hydrate microspherical carrier material is used in an amount between 60 and 99 wt% relative to the total weight of the catalyst.

The use of a supported catalyst may present the benefit of dispersing the active phase, increasing therefore the accessibility of the active sites. However, the intrinsic 25 activity of these sites may be reduced due to a strong interaction of the active phase with the support.

For a long time bulk catalyst for hydrodesulfurization (HDS) were thought to be poorly active. However, some recent works have been done in the last years.

The international application WO 2009/061295 discloses a method for preparing 30 bulk bimetallic Group Vl ll/Group VIB catalyst precursor at a pressure of less than 1 atmosphere. This leads to bulk catalyst having a rather low specific surface area.

The international application WO 2007/048598 discloses a method for preparing bulk metallic Group Vlll/Group VIB catalyst at high temperature, wherein the first and second metal compound remains at least partly in the solid state. The prior art method for preparing bulk catalyst may be insufficient in terms of efficacy, cost efficiency, may be difficult to upscale to industrial scale, may not be friendly enough toward environment, for example by using solvents which are toxic or which can have adverse effects on the environment, may consume too much energy, may not be able to produce catalyst precursors and/or catalysts effective enough, may not be continuous, and/or may reject a lot of reagents.

The prior art catalysts and/or catalyst precursors may be insufficient in terms of specific surface area, efficiency, for example activity, selectivity, temperature needed for catalysis, the vol ume and/or quantity needed , not resistant enough to degradation , and/or their activity may decrease too rapidly or they may be too sensitive to poisoning.

SUMMARY OF THE INVENTION

Following a first aspect, the invention has for subject matter a bulk catalyst precursor comprising Group VI 11 B and/or Group VIB metal, in particular of the NiMo, CoMo, NiW, CoW, CoNiMo or CoNiW type, having a specific surface SBET, superior or equal to 80 m ² /g, in particular superior or equal to 90 m ² /g, more particularly superior or equal to 100 m ² /g.

In this description the SBET is the specific surface according to Brunauer, Emmet and Teller. This specific surface is as defined in S. Brunauer, P. H. Emmett and E. Teller, J. Am. Chem. Soc, 1938, 60, 309.

Following a second aspect, the invention has for subject matter a method for preparing a bulk catalyst precursor, in particular comprising at least one metal from Group VI 11 B and/or one metal of Group VI B, more particularly of the NiMo, CoMo, NiW, CoW, CoNiMo or CoNiW type, comprising the following steps:

a) reacting precursors of the desired catalyst precursor in a mixture comprising, or consisting of, precursors and at least one solvent comprising, or consisting of, water and/or alcohol, said mixture being under a pressure superior or equal to 5 bars and a temperature superior or equal to 100°C, and

b) recovering catalyst precursor, in particular as particles.

BRIEF DESCRIPTION OF THE FIGURES

Figures 1 , 3, 5, 7, and 1 1 present XRD of catalyst precursors according to the invention. Figures 2, 4 and 6 show the scanning electron microscopy pictures of catalyst precursor particles according to the invention.

Figures 8, 9 and 10 show comparison of conversion obtained with catalysts according to the invention and with commercial catalysts.

DETAILED DESCRIPTION OF THE INVENTION

The solvent(s) of the reaction mixture comprises, or consists of, water and/or alcohol. The alcohol may be chosen from the group consisting of methanol, ethanol, n-propanol, iso-propanol and their mixtures.

In particular the solvent is a mixture of water and alcohol.

The molar ratio water/alcohol may range from 99/1 to 1 /99, in particular from 95/5 to 5/95, more particularly from 90/10 to 10/90, even more particularly from 80/20 to 20/80.

More particularly, the molar ratio water/alcohol ranges from 70/30 to 30/70, in particular from 65/35 to 35/65, more particularly from 60/40 to 40/60, even more particularly from 55/45 to 45/50.

Following an embodiment the molar ratio water/alcohol ranges from 53/47 to 47/53, in particular from 52/48 to 48/52, more particularly from 51/49 to 49/51 , even more particularly the molar ratio water/alcohol is 50/50.

The precursor(s) in the solvent(s) may be a suspension, a dispersion or a solution.

Following a first embodiment, the mixture is homogeneous. In particular the mixture solubilises the precursors of the desired catalyst precursor, in this case the mixture, in particular comprising or consisting of precursor(s) and the solvent, is a solution.

This may be advantageous in terms of conservation of the devices used, it can lead to less harsh conditions and/or it may allow keeping the device into good or working condition longer.

In particular, the mixture is free of C0 ₂ . This means in particular that the amount of C0 ₂ is inferior or equal to 0, 1 % by weight, in particular to 100 ppm by weight, more particularly to 10 ppm by weight, and even more particularly to 1 ppm by weight relative to the total weight of the mixture, except the C0 ₂ which may arise from a precursor which is carbonated.

The mixture may also be free of surfactant. This means in particular that the amount of surfactant is inferior or equal to 0,1 % by weight, in particular to 100 ppm by weight, more particularly to 10 ppm by weight, and even more particularly to 1 ppm by weight relative to the total weight of the mixture.

The mixture may also be free of alumina and/or zeolite and/or the mixture may be free of particles.

The pressure may be superior or equal to 50 bars, in particular superior or equal to 75 bars, more particularly superior or equal to 100 bars, and even more particularly superior or equal to 125 bars.

The temperature may be superior or equal to 150°C, in particular superior or equal to 1 75°C, more particularly superior or equal to 200°C, and even more particularly superior or equal to 225 °C.

The temperature and pressure may be superior or equal to 75 bars and 175°C, in particular to 100 bars and 200°C, more particularly to 125 bars and 225°C.

In particular, the mixture is under supercritical conditions, more particularly the reaction proceeds or is started while the mixture is under supercritical conditions.

Following a specific embodiment embodiment, the conditions are such as to get the mixture, in particular the solvents into supercritical, more particularly the pressure and temperature are such as to get the mixture into supercritical conditions.

In particular in case of ethanol a pressure superior or equal to 64 bars and a temperature superior or equal to 243°C, and in case of water a pressure superior or equal to 221 bars and a temperature superior or equal to 374°C may be used.

The precursors are soluble in alcohol and/or water.

The precursors may be chosen from metal complexes of the Group VI 11 B and/or of the Group VI, in particular Ni, Mo, Co and/or W, with acetylacetonate (acac), acetates, carbonates, nitrates, chlorides, hydroxides, alcoxydes, in particular methoxyde, ethoxyde and propoxyde, and their mixtures.

In particular the Group VI 11 B metal is a non-noble metal.

The molar ratio of the precursor(s) of the Metal of Group VI I I B / the precursor(s) of the Metal of the Group VI may range from 10/1 to 1/10, in particular from 7/3 to 3/7, more particularly from 6/4 to 4/6, and even more particularly is about 1/1.

The molar ratio of the precursor(s) of the Metal of Group VI I I B / the precursor(s) of the Metal of the Group VI may range from 70/30 to 30/70, in particular from 65/35 to 35/65, and more particularly from 60/40 to 40/60, even more particularly from 55/45 to 45/55. In particular an excess of the Metal of Group VI 11 B may be used. For example the molar ratio of the Metal of Group VII IB / the precursor(s) of the Metal of the Group VI may range from 70/30 to 50/50, in particular from 68/32 to 55/40, and more particularly from 67/33 to 60/40.

This may allow obtaining a catalyst precursor having alpha, hydrated and beta phases. This may in particular partly stabilise beta phase among alpha phase at room temperature, this beta phase being more active toward hydrogenation.

The catalyst precursor may comprise one, two or three of these three phases, I particular it comprises a high level of hydrated phase and a low level of alpha phase. The hydrated phase may be as shown on XRD of Figure 1 , the alpha phase as shown on XRD of Figure 5, and the beta phase as shown on XRD of Figure 1 1.

In particular the alpha, beta and hydrated phases from NiMo and/or CoMo are as disclosed in the following articles.

The articles from G. W. Smith, "The crystal structure of cobalt molybdate, comoo4 and nickel molybdate nimoo4," Acta Cr stallographica, vol. 15, pp. 1054- 1057, 1962, and from G. W. Smith and J. A. Ibers, "The crystal structure of cobalt molybdate, comoo4," Acta Crystallographica, vol. 19, pp. 269-275, 1969 disclose the alpha phase.

The articles from S. C. Abrahams and J. M. Reddy, "Crystal structure of the transition-metal molybdates. i. paramagnetic alpha-mnmoo4," The Journal of Chemical Physics, vol. 43, no. 7, pp. 2533-2543, 1965. [Online]. Available: http://- link.aip.org/link/?JCP/43/2533/1 and from A. W. Sleight and B. L. Chamberland, "Transition metal molybdates of the type amoo4," Inorganic Chemistry, vol. 7, no. 8, pp. 1672-1675, Aug. 1968. [Online]. Available: http://dx.doi.org/10.1021/ic50066a050 disclose the beta phase.

The articles from J. A. Rodriguez, S. Chaturvedi, J. C. Hanson, A. Albornoz, and J. L. Brito, "Electronic properties and phase transformations in comoo4 and nimoo4: Xanes and time-resolved synchrotron xrd studies," The Journal of Physical Chemistry B, vol. 102, no. 8, pp. 1347-1355, Feb. 1998. [Online]. Available: http://- dx.doi.org/10.1021/jp972137q, from J. A. Rodriguez, S. Chaturvedi, J. C. Hanson, and J. L. Brito, "Reaction of h2 and h2s with comoo4 and nimoo4: Tpr, xanes, time- resolved xrd, and molecular-orbital studies," The Journal of Physical Chemistry B, vol. 103, no. 5, pp. 770-781 , Feb. 1999. [Online]. Available: http://dx.doi.org/10.1021/- jp9831 15m, from Y. Ding, Y. Wan, Y. L. Min, W. Zhang, and S. H. Yu, "General synthesis and phase control of metal molybdate hydrates mmoo4-nh2o (m = co, ni, mn, n = 0, 3/4, 1 ) nano/microcrystals by a hydrothermal approach: Magnetic, photocatalytic, and electrochemical properties," Inorganic Chemistry, vol. 47, no. 17, pp. 7813-7823, Sep. 2008. [Online]. Available: http://dx.doi.org/10.1021/ic8007975, and from K. Eda, Y. Kato, Y. Ohshiro, T. Sugitani, and M. S. Whittingham, "Synthesis, crystal structure, and structural conversion of ni molybdate hydrate nimoo4 nh2o," Journal of Solid State Chemistry, vol . 1 83, no. 6, pp. 1334 - 1339, 2010. [Online]. Available: http://www.sciencedirect.com/science/article/B6WM2-4YV82W1 -3/2/- fa092f778e15544c3dd65f80c507a3a4 disclose the hydrated phase.

The method may in particular comprise a step of heating, also called annealing step, the precursor. This step may allow increasing the al pha phase. Thus the process allows tuning the ratios of the different phases.

In particular the precursor does not comprise the three phases, and more particularly:

- the precursor may comprise hydrated and beta phases, in a ratio hydrated/beta of more than 10. More particularly it comprises alpha phase in a ratio hydrated / alpha > 100. This precursor may correspond to a precursor directly obtained through the method of the invention, in particular with the supercritical conditions, and without an annealing step, more particularly with Ni and Mo as metals, and optionally other metals,

- the precursor ma y comprise only al pha phases. Thi s may m ean the ratio alpha/beta and alpha/hydrated are each > 100. This precursor may correspond to a precursor obtained through the method of the invention, in particular with the supercritical conditions, and with an annealing step and with a Ni/Mo ratio less or equal to 1 , and

- the precursor may comprise only alpha and beta phases. This may mean the ratio alpha/hydrated and beta/hydrated are each > 100. This precursor may correspond to a precursor obtained through the method of the invention, in particular with the supercritical conditions, and with an annealing step and with a Ni/Mo ratio > 1 .

The ratio of the different phases may be measured with XRD.

A precursor having a pure beta phase is shown on Figure 1 1 . This pure beta phase precursor may be obtained by annealing (3h at 400°C) a compound obtained according to the invention, in particular according to Examples 1 or 2. The XRD measure from Figure 1 1 is performed in an apparatus allowing to measure at the end of the annealing and at the annealing temperature. According to an embodiment, the catalyst precursor does not comprise a hexagonal phase or a metastable phase, i n particular such as disclosed in WO2007/048593 and WO2007/048598.

Such a catalyst precursor may lead, for example once sulfided, to a more efficient catalyst for HDS and/or deep-HDS (hydrodesulfuration).

Following one embodiment, the at least two, in particular all, precursors, are all in the same mixture, in particular solution, which is then brought to specific pressure and temperature conditions, in particular to supercritical conditions.

Following another embodiment at least two mixtures, in particular solutions, more particularly one mixture per precursor, is brought to specific pressure and temperature conditions, in particular to supercritical conditions and then are mixed together. This embodiment may prevent a reaction between precursors and/or precipitation before the precursors are brought to specific pressure and temperature conditions, in particular to supercritical conditions.

In order to solubilise a precursor in a mixture of water and alcohol, it is possible to proceed by first solubilise it in water and once solubilised in water to add alcohol or to first solubilise it in alcohol and once solubilised in alcohol then water is added.

In particular once the precursor is solubilised in a mixture of water and alcohol, the mixture is the one intended to be submitted to specific pressure and temperature conditions, more particularly to supercritical pressure and temperature conditions.

The bulk catalyst precursor presents a S _B ET superior or equal to 80 m ² /g, in particular superior or equal to 90 m ² /g, more particularly superior or equal to100 m ² /g, and more particularly a S _B ET inferior or equal to 1000 m ² /g, even more particularly inferior or equal to 500 m ² /g, and still even more particularly inferior or equal to 200 m ² /g.

The bulk catalyst precursor may present an alpha phase, a hydrated phase and/or a beta phase. More particularly the catalyst precursor presents a beta-phase, in particular it presents a beta-phase and an alpha phase. The bulk catalyst precursor may comprise a beta-phase in the alpha phase.

The alpha phase is also called the low temperature phase and the beta phase is also called the high temperature phase.

The structures are disclosed in the ICBD-PDF, formerly known as JCPDS. ICBD meaning International Centre for Diffraction Data and PDF meaning Powder Diffraction Files. These files may thus allow to characterize the phase(s) of the precursor of the invention. The presence of alpha and beta and hydrated phases, and even their ratios, may be determined by XRD (X-Ray Diffraction).

In particular, the bulk catalyst precursor comprises a hydrated phase. The hydrated phase may be characterised by the fact that it comprises water in the lattice of the crystal. More particularly it may comprise H ₂ 0 in an amount ranging from 10 to 200 mol%, more particularly from 25 to 150 mol%, still more particularly from 50 to 1 00 mol%, and even more particularly around 75 mol% compared to the catalyst precursor, such as NiMo, CoMo, NiW, CoW, CoNiMo or CoNiW type.

The catalyst precursors, and the catalysts obtai ned with these catalyst precursors, may exhibit a higher concentration of active sites compared to supported equivalent catalysts and catalyst precursors.

The bulk catalyst precursor may be recovered as particles. The particles of bulk catalyst precursor may be recovered through a filter, in particular a refrigerated filter. For example the filter may be refrigerated by an ice-bath.

The particles may also be recovered as dispersion or suspension in solution.

The method may be processed continuously. This may be advantageous in terms of easiness of production, of quantity produced and/or this may shorten the time of production, in particular as compared with batch methods.

In the method, the reaction may proceed in less than 10 minutes, in particular less than 5 minutes, and more particularly less than 1 minute.

The method may comprise a further step of calcinating the particles of catalyst precursor.

According to an embodiment, the invention has for subject matter a method for preparing a bulk catalyst precursor, in particular comprising at least one metal from Group VI 11 B and/or one metal of Group VI B, more particularly of the NiMo, CoMo, NiW, CoW, CoNiMo or CoNiW type, comprising the following steps:

a) reacting precursors of the desired catalyst precursor in a mixture comprising, or consisting of, precursors and at least one solvent comprising, or consisting of, water and/or alcohol, said mixture being under supercritical conditions, and b) recovering catalyst precursor, in particular as particles.

In particular, this method:

1 . is performed continuously,

2. is done with the mixture comprising water and alcohol, in particular chosen from methanol, ethanol, n-propanol, iso-propanol and their mixtures,

3. is performed with the reacting precursors in solution, 4. allows the "tuning of the precursor's phase, in particular through annealing, and/or

5. allows a short processing time, for example less than 1 0 minutes, in particular less than 5 minutes, and more particularly less than 1 minute.

More particularly the method comprises 1 , 2, 3, 4 or 5 of the preceding characteristics, and they may be defined more precisely according to the instant description.

Annealing and calcination have the same meaning in the present application.

The bulk catalyst precursor may be obtained or may be obtainable with the method disclosed in this description.

The bulk catalyst precursor comprising Group VI 11 B and/or Group VI B metal, in particular of the NiMo, CoMo, NiW, CoW, CoNiMo or CoNiW type, may have a S _B ET superior or equal to 80 m ² /g , in particular superior or equal to 90 m ² /g , more particularly superior or equal to 1 00 m ² /g. It may also have a S _B ET inferior or equal to 1 000 m ² /g, more particularly inferior or equal to 500 m ² /g, and even more particularly inferior or equal to 200 m ² /g.

The bulk catalyst precursor may have a content of C lower or equal to 1 % w/w, lower or equal to 0.5 % w/w.

The bulk catalyst precursor may have a content of N lower or equal to 0. 1 % w/w, lower or equal to 0.01 % w/w, or even lower than 0.001 % w/w.

These ratios may be measured with elemental analysis, also called CHNS.

The bulk catalyst precursor may comprise molar ratios of Metal of Group VI I IB / Metal of Group VI ranging from 1 0/1 to 1 /1 0 , in particular from 7/3 to 3/7 , more particularly from 6/4 to 4/6, and even more particularly is about 1 /1 .

It is to be noted that the molar ratio Group VI 1 1 B metal and/ Group VIB metal, such as Ni/Mo, Co/Mo, Ni/W, Co/W, CoNi/Mo or CoNi/W, may be different from 1 .

This ratio may depend on the initial ratio of precursors.

The bulk catalyst precursor may comprise alpha, beta and/or hydrated phase.

It may be advantageous to have catalyst precursor with a ratio of Group VI 1 1 B metal and/ Group VI B metal , such as N i/Mo, Co/Mo, N i/W, Co/W, CoN i/Mo or CoNi/W, superior to 1 , as it may lead to a catalyst precursor having an hydrated, an alpha and a beta phase.

Following another aspect, the invention has for subject matter a method for preparing a bulk catalyst comprising the step consisting to activate the catalyst precursor to catalyst. In particular, the bulk catalyst is obtained or obtainable from a bulk catalyst precursor.

In particular the catalyst precursor is activated by being sulfided. It may be sulfided by conventional methods, in particular those typically used in the art.

More precisely, it may be sulfided in a flow of pure hydrogen sulfide, in a mixture of hydrogen sulfide and hydrogen and/or in a flow of hydrogen and a mixture of light hydrocarbons containing at least one sulfur compound, at a temperature ranging from 150 to 800°C.

Following one embodiment, the catalysts is obtained by charging the catalyst precursor in a reactor and submits it to a hydrocarbon feedstock comprising at least one sulfur compound and hydrogen at a temperature above 100°C. In particular the reactor is the reactor in which the catalyst is used to process the reaction it catalyses, for example dehydrosulfuration.

The bulk catalyst comprises Group VI 11 B and/or Group VIB metal, in particular of the NiMo, CoMo, NiW, CoW, CoNiMo or CoNiW type, and may have a SBET superior or equal to 80 m ² /g, in particular superior or equal to 90 m ² /g, more particularly superior or equal to 100 m ² /g. It may also have a SBET inferior or equal to 1000 m ² /g, more particularly inferior or equal to 500 m ² /g, and even more particularly inferior or equal to 200 m ² /g.

Of course, the catalyst may be obtained or be obtainable with the method disclosed above.

The invention also has for subject matter a catalyst as defined above for hydroprocessing of a hydrocarbon feedstock, in particular comprising sulfur and/or nitrogen containing organic compounds.

The invention also has for subject matter the use of a catalyst as defined above for hydroprocessing of a hydrocarbon feedstock, in particular comprising sulfur and/or nitrogen containing organic compounds.

The invention also has for subject matter a method for deep or ultra deep hydrodesulfuration of sulfur and/or nitrogen containing hydrocarbon feed comprising contacting the feed with a bulk catalyst as above.

The following examples are presented in order to illustrate the invention.

EXAMPLES Example 1 : Ni-Mo oxides directly after synthesis in sc-H ₂ 0/EtOH (1 :1 molar)

The method to synthesize bulk catalyst precursor i s based on a ch em i ca l transformation of metallic precursors. The process falls into different steps:

A determined amount of the precursors is solubilized in the solvent, which is a mixture water/EtOH (molar ratio 1 : 1 ). That permits to solubilize metal l ic, i n this case molybdenum and nickel, precursors.

Mo02 ²⁺ [CH ₃ COCHCOCH ₃ ]2 is di rectly sol ubi l ized i n the m ixtu re whereas the Ni ²⁺ [OOC-CH ₃ ] ₂ is first put into distillate water before adding the proper quantity of alcohol.

The solutions are put into an ultrasonic bath to improve and quicken this step. The two solutions are then put together for a one-line injection or kept separate for a two- line injection process.

Practical ly, the molybdenum concentration is [Mo] = 7.2.10 ^"3 mol. L ^"1 and nickel concentration is the same to have the wished stoichiometry ( 1 : 1 molar in this example).

The solutions of precursors are injected, the mixture containing the precursors then reaches its supercritical condition, 290°C and 230 bars, in the reactor, and the chemical reaction takes pl ace l ead i ng to the n u cl eati on and g rowth of the nanoparticles. The time of residence being 55 seconds.

The nanoparticles thus formed in the reactor follow their way to the filter deepened in the ice bath to quench the growth of nanoparticles.

The system is then brought back to room temperature and atmospheric pressure by injecting water in the reactor to help cooling down and to wash the product.

Finally, once the experiment is over, the filter is cleaned with distilled water and the product is recovered by vacuum filtration of the resulting slurry, washed with distilled water, and the product is dried at room temperature and crushed in a mortar to condition it as a powder.

The catalyst precursor obtained exhibit the following properties:

S _BET : 134 ± 14 m ² .g ^"1 ,

CHNS: 0.34 ± 0.13 w% C ; 0.99 ± 0.26 w% H ; 0 w% N ; 0 w% S, and

ICP: Ni/Mo = 1 ± 0.08

The XRD of the obtained particles of NiMo catalyst precursor is shown on figure 1 and a scanning electron microscopy (SEM) picture of catalyst precursor particles is shown on figure 2. Example 2: Ni-Mo oxides after synthesis in sc-H ₂ 0/iPrOH (1 :1 molar)

The same protocol than in example 1 is used for example 2, except that Ethanol is changed for Isopropanol.

The catalyst precursor obtained exhibit the following properties:

S _BET : 179 ± 12 m ² .g ^"1

CHNS: 0.37 ± 0.1 1 w% C ; 1.24 ± 0.21 w% H ; 0 w% N ; 0 w% S

ICP: Ni/Mo = 1 ± 0.14

The XRD of the obtained particles of NiMo catalyst precursor is shown on figure 3 and a SEM picture of the particles is shown on figure 4.

Example 3: Ni-Mo oxides after calcination 3h at 400 °C with a synthesis in sc- H ₂ 0/iPrOH (1 :1 molar)

The same protocol than in example 1 is used, except that Ethanol is changed for Isopropanol and the powder is calcined 3 h at 400 °C.

The catalyst precursor obtained exhibit the following properties:

S _BET : 1 19 ± 10 m ² .g ^"1

CHNS: 0.1 ± 0.08 w% C ; 0.56 ± 0.1 1 w% H ; 0 w% N ; 0 w% S

ICP: Ni/Mo = 1 ± 0.14

The XRD of the obtained particles of NiMo catalyst precursor is shown on figure 5a and with more details on figure 5b. This XRD is representative of a pure alpha phase, and a microscopic enlargement of the particles is shown on figure 6.

Example 4: Co-Mo oxides synthesized in sc-H ₂ 0/iPrOH (1 :1 molar)

The same protocol than in example 1 is used, except that Ethanol is changed for Isopropanol and and Ni ²⁺ [OOC-CH ₃ ] ₂ is changed for Co ²⁺ [OOC-CH ₃ ] ₂ .

The catalyst precursor obtained exhibit the following properties:

CHNS: 0.37 ± 0.1 1 w% C ; 1.24 ± 0.21 w% H ; 0 w% N ; 0 w% S

ICP: Co/Mo = 1 ± 0.14

The XRD of the obtained particles of CoMo catalyst precursor is shown on figure 7.

Example 5: Conversion of naphthalene into tetraline with MT042: (66 at% Ni, 34 at% Mo, 110 m ² .g- ¹ )

Model feedstock This example is processed on the following model feedstock having the composition of the model feedstock described in Table 1.

Table 1

Characteristics of the model feedstock

This model feedstock has a density of 671 g.L ^"1 and a mean molar mass of 123 g.mol ^"1 . It is composed of 60 wt% of paraffins (saturated hydrocarbons - namely heptanes and dodecane), 30 wt% of olefins (unsaturated hydrocarbon - namely hexene and octene), and 10 wt% of aromatics hydrocarbons (naphthalene, benzene and toluene).

Reference catalysts

A com mercial catalyst is used as reference for the tests on N i MoO : N M (4 w% NiO, 14 w% M0O ₃ /Y-AI2O3, similar to catalysts classically described in the literature), and for the tests on CoMo0 ₄ : CM (3 wt% CoO, 14 wt% M0O3/AI2O3, similar to catalysts classically described in the literature).

For these examples, the powder of the catalyst is pelletized at 3.5 t for 1 min, crushed and sieved to particles between 0.25 pm and 0.425 pm. 0.31 mL of catalyst is mixed with silicon carbide up to 2 mL to form the catalytic bed. It is then subjected to a gas flow of 10 % in volume of H ₂ S in H ₂ for 5 h at 400 °C. In order to vary conversion, experiments were performed at three different temperatures for most of the catalysts. Starting at 320 °C, we then switch to 360 °C to finish at 400 °C. The LHSV were set at 19 h ^"1 and we varied the M _G /M _L from 5 to 8.17. The products of the reaction are analyzed in a chromatograph equipped with two detectors: a FID and a PFPD.

The catalyst precursors are obtained following the procedure described in example 1. In this example 5, the catalyst precursor MT042 is obtained following the examplel procedure and with a molar ratio Ni ²⁺ [OOC-CH ₃ ] ₂ to Mo0 ₂ ²⁺ [CH ₃ COCHCOCH ₃ ]2 of 1.95/1.

The powder of the catalyst precursor is pelletized at 3.5 1 for 1 min, crushed and sieved to particles between 0.25 pm and 0.425 pm. 0.31 mL of catalyst is mixed with silicon carbide up to 2 mL to form the catalytic bed.

The catalyst precursor is activated with a sulfidation step to convert the metal oxides into the metal sulfides, which are the active catalysts for HDS. The catalytic bed is subjected to a gas flow of 10 % in volume of H ₂ S in H ₂ for 5 h at 400 °C.

The results are shown on figure 8. Example 6: Influence of the composition on the catalytic activity with NM, MT044 (66 at% Ni, 34 at% Mo, 110 m ² .g ^"1 ), and MT072: (62 at% Ni, 38 at% Mo, 80 m ² .g- ¹ ), LHSV = 39 h ^_

In this example 6, the catalyst precursor MT044 is obtained following the examplel procedure and with a molar ratio Ni ²⁺ [OOC-CH ₃ ] ₂ to Mo0 ₂ ²⁺ [CH ₃ COCHCOCH ₃ ] ₂ of 1.95/1 , and the catalyst precursor MT072 is obtained following the examplel procedure and with a molar ratio Ni ²⁺ [OOC-CH ₃ ] ₂ to Mo0 ₂ ²⁺ [CH ₃ COCHCOCH ₃ ] ₂ of 1.63/1.

The powder of the catalyst precursor is pelletized at 3.5 1 for 1 min, crushed and sieved to particles between 0.25 pm and 0.425 pm. 0.31 mL of catalyst is mixed with silicon carbide up to 2 mL to form the catalytic bed. The catalyst precursor is activated with a sulfidation step to convert the metal oxides into the metal sulfides, which are the active catalysts for HDS. The catalytic bed is subjected to a gas flow of 10 % in volume of H ₂ S in H ₂ for 5 h at 400 °C.

The same protocol as in example 5 is followed but this time, the amount of catalyst was of 0.16 ml_, the LHSV was set at 39 h ^"1 and we fixed the M _G /M _L at 5. A forth test were carried out back at 320 °C.

The results are shown on figure 9.

Example 7: Influence of the promoter on the catalytic activity with CM, MT081 (50 at% Co, 50 at% Mo, 40 m ² .g ^"1 ), LHSV = 150 h ^_

In this example 7, the catalyst precursor MT081 is obtained according to example 4 procedure.

The powder of the catalyst precursor is pelletized at 3.5 1 for 1 min, crushed and sieved to particles between 0.25 pm and 0.425 pm. 0.31 ml_ of catalyst is mixed with silicon carbide up to 2 ml_ to form the catalytic bed.

The catalyst precursor is activated with a sulfidation step to convert the metal oxides into the metal sulfides, which are the active catalysts for HDS. The catalytic bed is subjected to a gas flow of 10 % in volume of H ₂ S in H ₂ for 5 h at 400 °C.

The same protocol as in example 5 is followed but this time, the amount of catalyst was of 40 μΙ_, the LHSV was set at 150 h ^"1 and we fixed the M _G /M _L at 5. A forth test was carried out back at 320 °C.

The results are shown on figure 10.

The examples 5 to 7 show that the catalyst obtained from the catalyst precursor exhibits excellent properties.

In particular Bulk HDS catalysts synthesized according to the invention, for example NiMo0 or CoMo0 , perform better than the commercial references they are compared with.

The bulk material shows better aromatics hydrogenation activity than the commercial references it is compared with.

For similar conversion under similar operating conditions, a lower mass of the catalyst according to the invention can be used than with the commercial reference NM or CM, respectively.

For similar conversion with similar amount of catalysts, a lower temperature can be used with the catalyst according to the invention than with NM or CM, respectively. For similar conversion with similar amount of catalysts, a lower H ₂ partial pressure can be used with the catalyst according to the invention than with NM or CM, respectively.

The catalyst according to the invention proves to be active for converting a real feedstock chosen among the most difficult to treat and with results comparable or superior to the commercial references tested.