A method for preparing an IZM-2-based catalyst by specific heat treatment and the use of the catalyst for isomerization of paraffin-based feedstock in the middle distillate.

Abstract

The present invention relates to a method for preparing a bifunctional catalyst using IZM-2 zeolite, a hydrogenation function and a matrix. The preparation method according to the invention uses a specific thermal treatment of the catalyst to improve the selectivity of the isomerization of paraffinic feedstocks in middle distillates.

Description

[Technical Field]

[0001] To meet the demand for middle distillates, i.e., fractions that can be incorporated into the pool of kerosene and / or gas oil, various methods may be used to produce middle distillates based on the use of petroleum, natural gas, or renewable resources.

[0002] The middle distillate base may thus be produced from crude or pre-treated renewable sources, particularly paraffinic feedstocks obtained from feedstocks derived from vegetable oils or animal fats, and also from mixtures of such feedstocks. Specifically, the feedstocks derived from renewable sources contain triglycerides or free fatty acids or ester-type chemical structures, and the structure and length of the hydrocarbon-based chains of these feedstocks are compatible with the hydrocarbons present in the middle distillate. After hydrogenation, the feedstocks derived from renewable sources produce paraffinic feedstocks that are free of sulfur compounds and aromatic compounds. These paraffinic feedstocks are typically composed of linear paraffins containing 9 to 25 carbon atoms.

[0003] The middle distillate base may be generated from natural gas, coal, or renewable sources via Fischer-Tropsch synthesis. In particular, "low-temperature" Fischer-Tropsch synthesis using a cobalt catalyst makes it possible to generate essentially paraffinic linear compounds with a large variable number of carbon atoms, typically 1 to 100 or even more. Separation steps may allow for the recovery of paraffinic feedstock containing 9 to 25 carbon atoms.

[0004] However, these middle distillate bases obtained after hydrogenation of vegetable oils or after the low-temperature Fischer-Tropsch synthesis method generally cannot be directly incorporated into kerosene or gas oil pools due to particularly poor low-temperature properties. Specifically, the linear or very unbranched high molecular weight paraffins present in these middle distillate bases result in a high pour point, and therefore solidify at low temperatures. For example, the pour point of a linear hydrocarbon containing 20 carbon atoms per molecule, typically found in middle distillate fractions, whose boiling point is equal to about 340°C, is about +37°C, which makes its use impossible. The specification for gas oil is -15°C. To lower the pour point value, these linear or very unbranched paraffins must be completely or partially removed.

[0005] This operation may be carried out by extraction with a solvent, such as propane or methyl ethyl ketone, a method known as propane dewaxing or methyl ethyl ketone (MEK) dewaxing. However, these techniques are expensive, redundant, and not always easy to implement.

[0006] Selective decomposition of the longest linear paraffin chains leads to the formation of compounds with lower molecular weights, some of which may be removed by distillation. Such selective decomposition of the longest linear paraffin chains is one solution for reducing the pour point value. Given their shape selectivity, zeolites are among the most widely used catalysts in this type of method. The most widely used catalyst in the category of dewaxing by selective decomposition is the MFI-framed zeolite ZSM-5, which has three-dimensional porosity with medium pores (openings containing 10 oxygen atoms, 10MR). However, the decomposition induced in such methods leads to the formation of large quantities of products with lower molecular weights, such as butane, propane, ethane, and methane, which significantly reduces the yield of the desired product.

[0007] Another solution to improve low-temperature behavior involves isomerizing long linear paraffins while minimizing decomposition as much as possible. This can be achieved by performing a hydrogenation isomerization method using a bifunctional catalyst. The bifunctional catalyst includes a Brønsted acid phase (e.g., zeolite) and a hydrogenation-dehydrogenation phase (e.g., platinum), as well as a matrix (e.g., alumina). The appropriate choice of acid phase makes it possible to promote the isomerization of long linear paraffins while minimizing decomposition. Thus, the shape selectivity of medium-pore (10MR) one-dimensional zeolites, such as zeolites ZSM-22, ZSM-23, NU-10, ZSM-48, and ZBM-30, makes them particularly suitable for use in obtaining catalysts that are selective for isomerization.

[0008] Recently, the applicant discovered that the use of IZM-2 zeolite is also suitable for obtaining catalysts that are selective for the isomerization of long paraffins. [Background technology]

[0009] (Conventional technology) However, it is well known that factors other than the acid phase influence the activity and selectivity of bifunctional catalysts. Since its initial study by Weisz or Coonradt and Garwood in the 1960s, the hydrogenation isomerization and hydrocracking of normal paraffins have been the subject of numerous academic studies. The most commonly accepted mechanism involves, firstly, dehydrogenation of the n-paraffin to an n-olefin on the hydrogenation-dehydrogenation phase, followed by protonation to a carbenium ion after diffusion into the acid phase. Following structural rearrangement and / or β-cleavage, the carbenium ion is desorbed from the acid phase in the form of an olefin after deprotonation. Then, after diffusion into the hydrogenation-dehydrogenation phase, the olefin is hydrogenated to form the final reaction product. When maximum isomerization selectivity is desired, the decomposition reaction on the acid phase should be limited. Therefore, it is desirable to rapidly hydrogenate the olefin intermediate with a hydrogenation / dehydrogenation function that is sufficiently active for the acid function and sufficiently close to the acid function. A bifunctional catalyst is considered "ideal" when the overall reaction rate is controlled solely by the acid-catalyzed process. In this case, the catalyst's activity and isomerization selectivity for a given acid function are determined by the properties of the acid phase. This case is well-known and has been reported in the academic literature in the case of isomerization of long paraffins, such as n-hexadecane (see, for example, Non-Patent Literature 1 and its references). However, the hydrogenation / dehydrogenation function can also catalyze reactions such as the hydrodelysis of paraffins. This reaction is undesirable because it can lead to a decrease in the isomerization selectivity of the bifunctional catalyst. Industrial bifunctional catalysts using a zeolite acting as the acid phase and a noble metal acting as the hydrogenation group are typically prepared by forming the zeolite with a matrix, which may be alumina, to obtain a formed support, and then depositing the metal phase on the support by impregnation. Generally, heat treatment processes related to shaping a support and depositing metallic functional groups involve contacting a solid with a gas that may contain oxygen (in the case of calcination) or hydrogen (in the case of reduction).Generally, these heat treatment processes are carried out in a gaseous medium in the absence of chlorine or chlorinated compounds and water to preserve the crystalline structure of the zeolite and avoid its dealuminization. The resistance of zeolites to dealuminization depends on their structure, their (acidic or non-acidic) form, temperature, and the presence of chlorine or chlorinated compounds and water (see Non-Patent Documents 2 and 3). Heat treatment using chlorine or chlorinated compounds in a gaseous medium has been reported in the context of regenerating spent catalysts using precious metals and zeolites. These treatments aim to redisperse precious metals that may have been sintered during the catalyst's use. These so-called oxychlorination heat treatments are carried out after the initial controlled calcination heat treatment of the spent catalyst and aim to remove coke present on the spent catalyst.

[0010] A patent application (Patent Document 1) discloses a regeneration procedure for a reforming catalyst using a group VIII metal and a zeolite. This regeneration procedure includes a combustion step to remove coke, followed by a heat treatment in the presence of water, a chlorine source, oxygen, and an inert gas.

[0011] Patent Document 2 discloses a method for regenerating a catalyst comprising at least one zeolite having a skeletal code EUO and at least one hydride-dehydrogenated metal. This method comprises the steps of removing most of the coke by combustion in the presence of an oxygen-containing gas at a temperature below 600°C, and oxychlorination in the presence of a gas mixture containing at least water, oxygen, and chlorine and / or at least one chlorinated compound.

[0012] Patent Document 3 discloses a catalyst regeneration procedure comprising an alumina matrix, a noble metal, and a zeolite having a silica-to-alumina molar ratio of at least 20. This procedure includes the steps of reducing the catalyst under hydrogen and redispersing the metal phase in the presence of a gas containing 1% to 20% by volume of oxygen and 0.001% to 10% by weight of hydrogen halide.

[0013] Patent Document 4 teaches a method for improving the catalytic activity of a catalyst containing L-type zeolite and at least one group VIII metal. This method involves contacting the catalyst with a gaseous medium containing water, a chlorine source, oxygen, and an inert gas at 450°C to 550°C. The product thus obtained is then contacted with a gaseous medium containing water, oxygen, and an inert gas at 450°C to 550°C to reduce the chlorine content on the catalyst to less than 2% by weight. Finally, the solid is reduced with a gas containing hydrogen and an inert gas at 350°C to 550°C to obtain the metal in its reduced form.

[0014] During research conducted to improve the selectivity and activity of long-chain paraffin isomerization of a bifunctional catalyst using IZM-2 zeolite as an acidic functional group, the applicant discovered a remarkable effect of the catalyst preparation procedure on the isomerization selectivity of the bifunctional catalyst using IZM-2 zeolite, while at least maintaining the activity of the catalyst.

[0015] Thus, the present invention relates to a method for preparing a bifunctional catalyst using IZM-2 zeolite, a hydrogenation functional group containing at least one noble metal from Group VIII, and a matrix.

[0016] Another subject of the present invention relates to catalysts obtained by the above method.

[0017] Another subject of the present invention relates to a method for isomerizing hydrogenated vegetable oils and / or animal oils or paraffinic feedstocks derived from low-temperature Fischer-Tropsch synthesis, the method using the bifunctional catalyst.

[0018] Remarkably, the preparation method of the present invention makes it possible to improve the isomerization selectivity of the catalyst while maintaining its activity. [Prior art documents] [Patent Documents]

[0019] [Patent Document 1] International Publication No. 94 / 05419 [Patent Document 2] Specification of French Patent Invention No. 2874516 [Patent Document 3] Specification of US Patent No. 4645761 [Patent Document 4] International Publication No. 9847615 [Non-Patent Document]

[0020] [Non-Patent Document 1] Written by P. S. F. Mendes et al., "AIChE Journal", Vol. 63, 2017, No. 7, pp. 2864 - 2875 [Non-Patent Document 2] Written by R. Lopez-Fonseca et al., "Applied Catalysis B: Environmental", Vol. 30, 2001, pp. 303 - 313 [Non-Patent Document 3] Written by Z. Konya et al., "Applied Catalysis B: Environmental", Vol. 8, 1996, pp. 391 - 404 [Summary of the Invention] [Means for Solving the Problems]

[0021] (Summary of the Invention) The present invention relates to a method for preparing a bifunctional catalyst comprising an acid functional group composed of IZM-2 zeolite, a hydrogenation functional group containing at least one noble metal selected from Group VIII of the periodic table, platinum and palladium, and a matrix. The method includes at least the following steps: i) A step of preparing a carrier for the catalyst by shaping IZM-2 zeolite with a matrix; the weight percentage of zeolite is preferably 1% to 50% relative to the weight of the carrier. ii) A step of depositing at least one noble metal from Group VIII of the periodic table by impregnating a carrier prepared in step i) that enables the acquisition of a solid with an aqueous solution containing at least the following compounds: - At least one ammonia-based compound selected from platinum(II) tetramine salts of formula Pt(NH3)4(OH)2, Pt(NH3)4(NO3)2 or Pt(NH3)4X2, platinum(IV) hexamine salt of formula Pt(NH3)6X4; platinum(IV) halopentamine salt of formula (PtX(NH3)5)X3; platinum N-tetrahalodiamine salt of formula PtX4(NH3)2; and halogenated compounds of formula H(Pt(acac)2X); palladium(II) salts Pd(NH3)4SO4 or Pd(NH3)4X2, where X is a halogen selected from chlorine, fluorine, bromine and iodine, and X is preferably chlorine, and "acac" represents the acetylacetonate group (of the empirical formula C5H7O2), and is a compound derived from acetylacetone. iii) At least one heat treatment step; the solid prepared in step ii) is brought into contact with at least one gas mixture containing oxygen, water, chlorine and / or at least one chlorinated compound, and the temperature during the heat treatment step is 200°C to 1100°C.

[0022] The advantage of the present invention is to provide a method for preparing a bifunctional catalyst comprising an acid phase based on IZM-2 zeolite and a hydrogenation functional group based on a noble metal from Group VIII, which allows for improvement of the isomerization selectivity of the long-chain paraffin of the catalyst by performing the heat treatment in step iii), while at least maintaining the activity of the catalyst.

[0023] Without wishing to be bound by any theory, the applicant believes that the improvement of the isomerization selectivity of the catalyst to long-chain paraffins and the maintenance of its activity can be achieved by the combination of steps carried out in the method according to the present invention, specifically steps ii) and iii). The systematic improvement in the maximum isomerization yield observed appears to be related to the reduction in the hydrocracking activity of the catalyst according to the present invention.

[0024] Another advantage of the present invention is to provide a method for isomerizing hydrogenated vegetable oils and / or animal oils or paraffinic feedstocks derived from low-temperature Fischer-Tropsch synthesis using the bifunctional catalyst thus obtained, wherein the use of the heat treatment in step iii) allows for better selectivity for the middle distillate, and the activity of the catalyst is at least maintained. [Modes for carrying out the invention]

[0025] (Detailed description of the invention) According to the present invention, the present invention relates to a method for preparing a bifunctional catalyst comprising an acid functional group composed of IZM-2 zeolite, a hydrogenation functional group containing at least one noble metal from Group VIII of the periodic table, selected individually or as a mixture from platinum and palladium, and a matrix.

[0026] (catalyst) The catalyst prepared according to the present invention includes IZM-2 zeolite, which constitutes the acidic functional group of the catalyst. The IZM-2 zeolite has a crystalline structure.

[0027] IZM-2 zeolite is a crystalline, microporous solid having the crystal structure described in patent application FR 2 918 050. A method for preparing IZM-2 zeolite is also described in the same patent application.

[0028] The aforementioned solid IZM-2 is expressed on an anhydrous basis and has a chemical composition defined by the following general formula with respect to the moles of oxide: XO2:aY2O3:bM2 / nO, where X represents at least one tetravalent element, Y represents at least one trivalent element, and M is at least one alkali metal and / or at least one alkaline earth metal with valency n.

[0029] X is preferably selected from silicon, germanium, titanium, and mixtures of at least two of these tetravalent elements. More preferably, X is silicon, and Y is preferably selected from aluminum, boron, iron, indium, and gallium. More preferably, Y is aluminum. M is preferably selected from lithium, sodium, potassium, calcium, magnesium, and mixtures of at least two of these metals, and more preferably, M is sodium. Preferably, X represents silicon; the crystalline solid IZM-2 according to the present invention is a completely silicic solid when element Y is not present in the composition of the solid IZM-2. It is also advantageous to use a mixture of several elements X as element X, in particular a mixture of silicon and another element X selected from germanium and titanium, preferably germanium. Thus, when silicon is present as a mixture with another element X, the crystalline solid IZM-2 according to the present invention is a crystalline metallosilicate and exhibits the same X-ray diffraction pattern as those described in Table 1 when it is in its calcined form. More preferably, in the presence of element Y, X is silicon and Y is aluminum: therefore, the crystalline solid IZM-2 according to the present invention is an aluminosilicate.

[0030] Preferably, the IZM-2 zeolite is in the form of an aluminosilicate.

[0031] Preferably, the molar ratio Si / Al (silicon atoms to aluminum atoms) is less than 200, preferably less than 150, and very preferably less than 120.

[0032] The IZM-2 zeolite incorporated in the composition of the support for the catalyst prepared according to the present invention is, advantageously, replaced by at least one treatment with a solution of at least one ammonium salt to obtain the ammonium form of the IZM-2 zeolite, which, once calcined, is acid (H +This leads to the ) type. This exchange step may be performed at any step in the preparation of the catalyst, namely after the step of preparing the IZM-2 zeolite, after the step of forming the IZM-2 zeolite with the matrix, or even after the step of introducing the hydride-dehydrogenated metal.

[0033] The IZM-2 zeolite incorporated in the composition of the support for the catalyst used in the method according to the present invention is, advantageously, at least partially, preferably substantially completely, of an acidic type, i.e., acid (H + It is of the ) type.

[0034] According to the present invention, the prepared catalyst comprises at least one matrix, which may be amorphous or crystalline.

[0035] Preferably, the matrix is ​​advantageously selected from the group formed by alumina, silica, silica-alumina, clay, titanium oxide, boron oxide, and zirconia, and may be used alone or in mixtures, or alternatively, an aluminate may be selected. Preferably, alumina is used as the matrix. Preferably, the matrix contains alumina in all its forms known to those skilled in the art, such as alpha, gamma, eta, and delta type alumina. The alumina differs, in particular, in their specific surface area and their pore volume.

[0036] The shaped mixture of matrix and IZM-2 zeolite constitutes the support for the catalyst.

[0037] (Step i): Preparation of the carrier) According to the present invention, the method includes step i) forming the IZM-2 zeolite with a matrix such that the weight percentage of the zeolite is advantageously 1% to 50%, preferably 2% to 30%, and preferably 5% to 20%, relative to the weight of the carrier.

[0038] (Shaping) The carrier for the catalyst used in the method according to the present invention may be shaped by any technique known to those skilled in the art. Shaping may be carried out by, for example, extrusion, pelletization, oil droplet method, rotary plate granulation, or any other method known to those skilled in the art. The carrier thus obtained may be of various shapes and sizes. Preferably, step i) is carried out by kneading and extrusion.

[0039] During the formation of the carrier by kneading and extrusion, the IZM-2 zeolite may be introduced during the dissolution or suspension of an alumina compound or alumina precursor, such as boehmite. The IZM-2 zeolite may be in the form of, for example, a powder, a ground powder, a suspension, or a suspension that has undergone deagglomeration treatment, for example, but not limited to these. For example, the zeolite may be advantageously placed in an acidified or non-acidified suspension at a concentration adjusted to the target final IZM-2 content in the catalyst according to the present invention. This suspension, commonly called a slip, is then mixed with the alumina compound or alumina precursor.

[0040] Furthermore, the use of additives may be advantageously done to facilitate the shaping of the carrier and / or to improve the final mechanical properties, as is well known to those skilled in the art. Examples of additives that may be specifically mentioned include cellulose, carboxymethylcellulose, carboxyethylcellulose, tall oil, xanthan gum, surfactants, flocculants, such as polyacrylamide, carbon black, starch, stearic acid, polyacrylic alcohol, polyvinyl alcohol, biopolymers, glucose, polyethylene glycol, and the like.

[0041] Water may be added or removed, advantageously, to adjust the viscosity of the paste to be extruded. This step may be performed, advantageously, at any stage in the mixing process.

[0042] To adjust the solid content of the paste to be extruded and to make the paste extrudeable, compounds that are mainly solids, preferably oxides or hydrates, may be added. Hydrates are preferably used, and aluminum hydrate is even more preferably used. The ignition loss of this hydrate is advantageously greater than 15%.

[0043] The extrusion of the paste derived from the mixing process may be advantageously carried out by any conventional commercially available tool. The paste derived from mixing may be advantageously extruded through a die, for example, using a piston or a single-screw or twin-screw extruder. The extrusion may be advantageously carried out by any method known to those skilled in the art.

[0044] The catalyst support prepared in step i) of the present invention is generally in the form of a cylindrical or multi-lobed extruder, for example, a straight or twisted two-lobed, three-lobed, or multi-lobed extruder, but may be manufactured and used in the form of a pulverized powder, tablet, ring, bead, and / or disc. Preferably, the catalyst support according to the present invention is in the form of a sphere or an extruder. Advantageously, the support is in the form of an extruder having a diameter of 0.5 to 5 mm, more specifically 0.7 to 2.5 mm. The shape may be cylindrical (which may be hollow or not) and / or twisted and / or multi-lobed (e.g., 2, 3, 4, or 5 lobes) cylindrical and / or ring-shaped. A multi-lobed shape is advantageously preferred.

[0045] (Drying) The carrier thus obtained at the end of shaping step i) may be subject to a drying step, which may be performed by any technique known to those skilled in the art.

[0046] Preferably, drying is carried out under a flow of air. The drying may be carried out under a flow of any oxidizing, reducing, or inert gas. Preferably, drying is carried out at a temperature advantageously between 50°C and 180°C, preferably between 60°C and 150°C, and most preferably between 80°C and 130°C.

[0047] (Firing) The carrier is, in some cases, dried and then preferably subjected to a calcination process.

[0048] The calcination process is preferably carried out at a temperature of more than 200°C and less than or equal to 1100°C, preferably by flashing with air, for example, in the presence of molecular oxygen. The calcination process may preferably be carried out in a transverse floor, a swept floor, or a static atmosphere. For example, the oven used may be a rotary oven or a vertical oven with radially transverse layers. Preferably, the calcination process is carried out over a period of more than 1 hour at 200°C and less than 1 hour at 1100°C. For shaped and optionally dried carriers, calcination may be carried out preferably in the presence of water vapor and / or acidic or basic vapors. For example, calcination may be carried out under partial pressure of ammonia.

[0049] (Post-firing treatment) Post-calcination treatment may, in some cases, be performed to improve the properties of the calcined carrier, particularly its microstructure.

[0050] Therefore, the catalyst support used in the method according to the present invention may be subjected to hydrothermal treatment in a sealed atmosphere. The term "hydrothermal treatment in a sealed atmosphere" means treatment in an autoclave in the presence of water at a temperature above ambient temperature, preferably above 25°C, and preferably above 30°C.

[0051] In this hydrothermal treatment process, the carrier may be impregnated, advantageously prior to its autoclave treatment (autoclave treatment may be performed in either the vapor or liquid phase, and this vapor or liquid phase of the autoclave may be acidic or not). This impregnation may be advantageously acidic or not prior to the autoclave treatment. This impregnation may be advantageously dry or by immersing the carrier in an acidic aqueous solution prior to the autoclave treatment. The term "dry impregnation" means placing the carrier in contact with a solution of a volume less than or equal to the total pore volume of the carrier. Preferably, the impregnation is carried out dry. The autoclave is preferably a rotary basket type autoclave, for example, as defined in patent application EP 0 387 109 A. The temperature during the autoclave treatment may be 100°C to 250°C over a period of 30 minutes to 3 hours.

[0052] (Step ii): Deposition of hydrogenation-dehydrogenation functional groups) According to the present invention, the deposition of the hydrogenation-dehydrogenation functional group is performed after the shaping step i).

[0053] According to the present invention, the method includes step ii) depositing at least one noble metal from Group VIII of the periodic table by impregnating a carrier prepared in step i) which enables obtaining a solid, and optionally undergoing drying and / or calcination and / or post-calcination treatment, with an aqueous solution containing at least the following compounds: - At least one ammonia-based compound selected from platinum(II) tetramine salts of formula Pt(NH3)4(OH)2, Pt(NH3)4(NO3)2 or Pt(NH3)4X2, platinum(IV) hexamine salt of formula Pt(NH3)6X4; platinum(IV) halopentamine salt of formula (PtX(NH3)5)X3; platinum N-tetrahalodiamine salt of formula PtX4(NH3)2; and halogenated compounds of formula H(Pt(acac)2X); palladium(II) salts Pd(NH3)4SO4 or Pd(NH3)4X2, where X is a halogen selected from chlorine, fluorine, bromine and iodine, and X is preferably chlorine, and "acac" represents the acetylacetonate group (of the empirical formula C5H7O2), and the compound is derived from acetylacetone.

[0054] The hydrogenation-dehydrogenation functional group may be introduced advantageously before or after, preferably after, the calcination of the support.

[0055] According to the present invention, the carrier is impregnated with an aqueous solution. The carrier is preferably impregnated by a "dry" or "incipient wetness" impregnation or over-impregnation method, which are well known to those skilled in the art. The impregnation may be advantageously carried out in a single step with a solution containing all of the constituent elements of the final catalyst. Preferably, a "dry" or "incipient wetness" impregnation method is used.

[0056] By performing step ii) by impregnating a support with an aqueous solution containing a specific ammonia-based metal salt claimed by the patent, it becomes possible to produce a two-functional catalyst containing an acidic phase based on IZM-2 zeolite and a hydrogenation functional group based on a Group VIII noble metal, wherein the Group VIII metal is localized on the outer surface of the IZM-2 zeolite crystal and / or in the microporous regions of the IZM-2 zeolite, i.e., within the IZM-2 zeolite crystal.

[0057] According to the present invention, the bifunctional catalyst prepared by the present invention comprises at least one Group VIII noble metal selected from platinum and palladium, either alone or as a mixture, and platinum is very preferably selected.

[0058] Preferably, step ii) consists of depositing at least one precious metal, preferably platinum, which is done by impregnating the carrier prepared in step i) with an aqueous solution containing an ammonia-based compound selected from the following: platinum(II) tetramine salt of formula Pt(NH3)4(OH)2, Pt(NH3)4(NO3) or Pt(NH3)4X2; platinum(IV) hexamine salt of formula Pt(NH3)6X4; platinum(IV) halopentamine salt of formula (PtX(NH3)5)X3; platinum N-tetrahalodiamine salt of formula PtX4(NH3)2; and halogenated compounds of formula H(Pt(acac)2X); preferably platinum(II) tetramine salt of formula Pt(NH3)4(OH)2, Pt(NH3)4(NO3) or Pt(NH3)4X2, where X and "acac" have the meanings described above.

[0059] Preferably, step ii) is carried out by depositing a noble metal, preferably platinum, on the carrier in a weight relative to the total mass of the catalyst, with a content of 0.01% to 4%, preferably 0.05% to 2%, and more preferably 0.05% to 1%.

[0060] Preferably, the impregnation solution may contain, individually or in mixtures, at least one ammonium salt that does not contain noble metals, selected from ammonium nitrate (NH4NO3), ammonium chloride (NH4Cl), ammonium sulfate (NH4)2SO4, ammonium hydroxide (NH4OH), ammonium bicarbonate (NH4HCO3), and ammonium acetate (NH4H3C2O2), preferably individually or in mixtures from ammonium nitrate (NH4NO3), ammonium chloride (NH4Cl), and ammonium acetate (NH4H3C2O2).

[0061] In cases where the impregnation solution also contains ammonium salts that do not contain noble metals, the concentrations of various species in the solution are set such that the molar ratio between the ammonium salts that do not contain noble metals and the noble metals is 0.1 to 400, preferably 0.2 to 200, and very preferably 0.3 to 150.

[0062] The platinum concentration in the impregnation solution is adjusted to obtain the desired content of the precious metal in the final catalyst.

[0063] Castan microprobes allow checking whether an element (platinum in this case) is uniformly distributed in the catalyst by calculating the distribution coefficient (see L. Sorbier, Determining the Distribution of Metal by Electron Probe Micro Analysis, in: H. Toulhoat, P. Raybaud (Eds.), Catalysis by Transition Metal Sulphides, Ed. Technip, Paris, 2013, pp. 407-411 and cited references). The macroscopic distribution coefficient for platinum obtained from its profile determined by the Castan microprobe is defined as the ratio of the platinum concentration at the core of the extruded to the concentration at the edge of the same extruded, and is between 0.7 and 1.3, preferably between 0.8 and 1.2. A value of this ratio in the range of 1 is evidence of the homogeneity of the platinum distribution in the catalyst.

[0064] The preferential localization of noble metals from Group VIII within and / or on the outer surface of the IZM-2 zeolite crystal may also be demonstrated by a Castan microprobe. Several extrudes are coated with resin (Struers, Ballerup), then polished, and metallized with carbon. The sample volume is then introduced into a Jeol JXA8100 instrument to analyze the local composition of silicon, aluminum, and platinum at various points. Starting with the local compositions of aluminum and silicon, and knowing the silicon composition of the zeolite, the alumina / (IZM-2+alumina) mass ratio may be estimated for each point analyzed. The change in the local composition of platinum in response to the local mass ratio of alumina / (IZM-2+alumina) can thus be plotted, and the preferential localization of platinum on alumina or zeolite can be checked. If the local composition of platinum increases in response to an increase in the local mass ratio of alumina / (IZM-2+alumina), platinum preferentially localizes on the alumina. If the local composition of platinum decreases in response to an increase in the local mass ratio of alumina / (IZM-2+alumina), platinum preferentially localizes on the zeolite.

[0065] The dispersion of one or more noble metals from Group VIII is determined by chemiadsorption, for example by H2 / O2 titration or carbon monoxide chemiadsorption, to be 10% to 100%, preferably 20% to 100%, and more preferably 30% to 100%.

[0066] In one embodiment, the aqueous solution from step ii) or a different aqueous solution from step ii) may contain a precursor of a metal preferably selected from gallium, indium, tin, and rhenium, from groups IIIA, IVA, and VIIB of the periodic table. All such precursors of metal may be suitable for use.

[0067] In cases where a different solution is used than that in step ii), the deposition of various elements is carried out sequentially.

[0068] According to one modification, the metal precursor may be impregnated on a carrier derived from step i) separately from the precious metal precursor from Group VIII.

[0069] If at least one metal from Group IIIA, Group IVA, and Group VIIB is added separately, it is preferable that it be added after the Group VIII metal. In this case, the second optional step of impregnation with at least one aqueous solution containing a precursor of a metal from Group IIIA, Group IVA, and Group VIIB may be advantageously performed after step ii).

[0070] Additional metals selected from Group IIIA, Group IVA, and Group VIIB may be introduced by aqueous solutions containing compounds selected from chlorides, bromides, and nitrates of metals from Group IIIA, Group IVA, and Group VIIB. For example, in the case of indium, nitrates or chlorides are favorably used, and in the case of rhenium, perrhenic acid is favorably used. Additional metals selected from Group IIIA, Group IVA, and Group VIIB may also be introduced via a solution containing a complex of the said metal, preferably a polyketone complex of the said metal, and at least one organic compound selected from the group consisting of hydrocarbyl metals selected from alkyl, cycloalkyl, aryl, alkylaryl, and arylalkyl metals. In the latter case, the introduction of the metal is favorably carried out using a solution of the organometallic compound of the said metal in an organic solvent. Organohalogen compounds of the metal may also be used. Organic compounds of metals that may be mentioned particularly include tetrabutyltin in the case of tin and triphenylindium in the case of indium.

[0071] If additional metals selected from Group IIIA, Group IVA, and Group VIB are introduced before the Group VIII metal, the Group IIIA, Group IVA, and / or Group VIB metal compounds used are generally selected from the group consisting of metal halides, nitrates, acetates, tartrates, carbonates, and oxalates. The introduction is advantageously carried out in an aqueous solution containing the compound. However, it may also be introduced using an organometallic compound of the metal, such as a solution of tetrabutyltin. In this case, calcination in air is performed before introducing at least one Group VIII metal.

[0072] In cases where several sequential impregnation steps are performed, intermediate drying and / or firing and / or reduction steps may be advantageously performed between the sequential impregnation steps with various metals.

[0073] Preferably, the deposition (one or more times) is carried out to deposit metals from Group IIIA, Group IVA, and Group VIIB onto the carrier in a content of 0.01% to 2% by weight, preferably 0.05% to 1% by weight, relative to the total mass of the catalyst.

[0074] At least one drying step may be advantageously performed after the impregnation step (one or more times), preferably after step ii). The drying step may be advantageously performed by any technique known to those skilled in the art.

[0075] Preferably, drying is carried out under a flow of air. The drying may be carried out under a flow of any oxidizing, reducing, or inert gas. Preferably, drying is carried out at a temperature advantageously between 50°C and 180°C, preferably between 60°C and 150°C, and most preferably between 80°C and 130°C.

[0076] (Step iii): Heat treatment of the solid obtained from step ii) According to the present invention, the method comprises at least one heat treatment step iii), wherein the solid obtained from step ii) is brought into contact with at least one gas mixture containing oxygen, water, chlorine and / or at least one chlorinated compound, and the heat treatment step is carried out at a temperature of 200°C to 1100°C.

[0077] According to the present invention, at least one heat treatment step of the solid obtained in step ii) is carried out after step ii), preferably after at least one drying step.

[0078] According to the present invention, the heat treatment is carried out by bringing the solid obtained from step ii) into contact with a gas containing molecular oxygen, water, chlorine and / or at least one chlorinated compound at a temperature of over 200°C and 1100°C or less, preferably over 250°C and less than 800°C, more preferably over 300°C and less than 700°C, and very preferably over 400°C and less than 600°C.

[0079] The weight content of oxygen in the gas during the heat treatment in step iii) is preferably 10% to 50% by weight, and preferably 15% to 35% by weight.

[0080] The weight content of water in the gas during the heat treatment in step iii) is preferably 0.02% to 10% by weight, and preferably 0.02% to 5% by weight.

[0081] The weight content of chlorine and / or chlorinated compounds in the gas during the heat treatment in step iii) is preferably 0.02% to 5% by weight, and preferably 0.1% to 3% by weight.

[0082] The chlorinated compound may be an inorganic or organic chlorinated compound. The inorganic chlorinated compound is preferably hydrochloric acid (HCl). The organic chlorinated compound is preferably selected from chloroalkanes, preferably from carbon tetrachloride, dichloropropane, dichloroethane, and chloroform.

[0083] Preferably, the method may advantageously include a step between step ii) and the heat treatment step iii) in which the solid obtained from step ii) is brought into contact with a gas that contains oxygen but does not contain chlorine and / or at least one chlorinated compound.

[0084] In this case, the solid obtained from step ii) is brought into contact with the gas containing oxygen but not containing chlorine and / or at least one chlorinated compound until it reaches the desired temperature for carrying out step iii), i.e., the temperature for injecting water and chlorine and / or at least one chlorinated compound.

[0085] The temperature for the injection of water and chlorine and / or at least one chlorinated compound is preferably above 200°C and 1100°C or less, preferably above 250°C and less than 800°C, more preferably above 300°C and less than 700°C, and very preferably above 400°C and less than 600°C.

[0086] According to the first embodiment, at least one temperature holding can be performed to reach the temperature required for the heat treatment step iii).

[0087] According to the second embodiment, temperature holding until the temperature for heat treatment step iii) is reached is not performed.

[0088] According to the present invention, heat treatment step iii) is carried out in the presence of water. Preferably, water is introduced either together with a gas that contains oxygen but does not contain chlorine or chlorinated compounds, or when chlorine and / or chlorinated compounds are introduced.

[0089] Preferably, water is introduced when chlorine and / or chlorinated compounds are introduced.

[0090] The heat treatment step iii) may be advantageously carried out on a transverse floor, on a swept floor, or in a static atmosphere. For example, the oven used may be a rotary oven or a vertical oven with radially transverse layers.

[0091] The temperature reduction can be advantageously carried out under a gas mixture containing oxygen, optionally water vapor, and free of chlorine. The solid is advantageously cooled in contact with the gas mixture, preferably from a temperature of 400°C or lower.

[0092] In a first preferred embodiment of this method, the solid obtained from step ii) is first brought into contact with a first gas mixture containing oxygen at room temperature, wherein the weight content of oxygen in the gas is 10% to 50% by weight, preferably 15% to 35% by weight. The gas mixture does not contain chlorine and / or chlorinated compounds, and its water content is less than 4% by weight. Heating in contact with the gas mixture is generally carried out gradually until the target temperature is reached. Typically, the heating rate is 1°C to 10°C per minute. Several holdings at various temperatures may be carried out if the first gas mixture is used before reaching the temperature for performing the heat treatment step iii). During step iii), the solid is brought into contact with a second gas mixture containing oxygen, chlorine and / or at least one chlorinated compound, and water. The second gas mixture is advantageously obtained by continuously injecting water and chlorine and / or at least one chlorinated compound into the first gas mixture.

[0093] The temperature is preferably 400°C to 600°C, and the duration of this holding is preferably 1 to 10 hours. The weight content of water in the second gas mixture is preferably 0.02% to 10% by weight, and more preferably 0.02% to 5% by weight. The amount of chlorine and / or chlorinated compounds in the second gas mixture is preferably 0.02% to 5% by weight, and more preferably 0.1% to 3% by weight. The oxygen content in the second gas mixture is preferably 10% to 50% by weight. Once the holding in contact with the second gas mixture is completed, the solid is then cooled to a temperature preferably below 400°C in contact with the second gas mixture. The solid is then cooled to room temperature in contact with a third gas mixture that does not contain chlorine and contains oxygen and optionally water vapor, preferably dry air. The third gas mixture preferably consists of the first gas mixture with the continuous injection of water and chlorine and / or at least one chlorinated compound omitted.

[0094] In a second preferred embodiment of the present method, the solid obtained from step ii) is first brought into contact with a first gas mixture containing oxygen at room temperature, wherein the weight content of oxygen in the gas is 10% to 50% by weight, preferably 15% to 35% by weight. The gas mixture does not contain chlorine and chlorinated compounds, and its weight content of water is less than 4% by weight. Heating in contact with the gas mixture is generally carried out gradually until the target temperature is reached. Unlike the first embodiment, once the temperature for the first gas mixture to be used to perform heat treatment step iii) is reached, no temperature holding is performed. Preferably, the heating rate is 1°C to 10°C per minute. The target temperature is preferably 400°C to 600°C. Once the desired temperature is reached, the solid is brought into contact with a second gas mixture containing oxygen, chlorine and / or chlorinated compounds, and water. The second gas mixture preferably consists of the first gas mixture to which water and chlorine and / or at least one chlorinated compound are continuously injected.

[0095] The temperature is preferably 400°C to 600°C, and the duration of this holding is preferably 1 to 10 hours. The weight content of water in the second gas mixture is preferably 0.02% to 10% by weight, and more preferably 0.02% to 5% by weight. The weight content of chlorine and / or chlorinated compounds in the second gas mixture is preferably 0.02% to 5% by weight, and more preferably 0.1% to 3% by weight. The weight content of oxygen in the second gas mixture is preferably 10% to 50% by weight. Once the holding in contact with the second gas mixture is completed, the solid is then cooled to a temperature preferably below 400°C in contact with the second gas mixture. The solid is then cooled to room temperature in contact with a third gas mixture that does not contain chlorine and contains oxygen and optionally water vapor, preferably dry air. The third gas mixture preferably consists of the first gas mixture with water and the continuous injection of chlorine and / or at least one chlorinated compound omitted.

[0096] Prior to its use in the isomerization method according to the present invention, the catalyst obtained at the end of the preparation method according to the present invention is preferably subjected to a reduction step. This reduction step is advantageously carried out by treatment under hydrogen, at a temperature of 150°C to 650°C, and at a total pressure of 0.1 to 25 MPa. For example, the reduction consists of holding at 150°C for 2 hours, followed by heating to 450°C at a rate of 1°C / min, and then holding at 450°C for 2 hours; throughout this reduction step, the hydrogen flow rate is 1000 standard m³ of hydrogen per ton of catalyst weight. 3 The total pressure is maintained at a constant 0.2 MPa. Any ex situ reduction method may be advantageously assumed. Pre-reduction of the final catalyst outside the situ may be carried out under a hydrogen flow, for example, at a temperature of 450°C to 600°C for a period of 0.5 to 4 hours.

[0097] The catalyst may also advantageously include sulfur. In cases where the catalyst of the present invention contains sulfur, the sulfur may be introduced in any step of the catalyst preparation, or alternatively, before the catalytic reaction, by in situ and / or ex situ sulfidation. In the case of in situ sulfidation, reduction is performed before sulfidation if the catalyst has not been reduced beforehand. In the case of ex situ sulfidation, reduction is performed, followed by sulfidation. Sulfidation is preferably carried out in the presence of hydrogen using any sulfidating agent well known to those skilled in the art, such as dimethyl sulfide or hydrogen sulfide.

[0098] The catalysts according to the present invention are available in various shapes and sizes. They are generally used in the form of cylindrical extrudes and / or multi-lobed extrudes, e.g., straight and / or twisted two-lobed, three-lobed, or multi-lobed extrudes, but may also be manufactured and used in the form of pulverized powder, tablets, rings, beads, and / or discs. Preferably, the catalyst used in the method according to the present invention is in the form of a sphere or an extruded. Advantageously, the catalyst is in the form of an extruded having a diameter of 0.5 to 5 mm, more specifically 0.7 to 2.5 mm. The shape may be cylindrical (which may be hollow or not) and / or twisted and / or multi-lobed (e.g., 2, 3, 4, or 5 lobes) and / or ring-shaped. Multi-lobed shapes are advantageously preferred. The deposition of metal does not alter the shape of the carrier.

[0099] The preparation method according to the present invention makes it possible to obtain a two-functional catalyst containing an acidic phase based on IZM-2 zeolite and a hydrogenation functional group based on a Group VIII noble metal.

[0100] Another subject of the present invention relates to a catalyst obtained by a method according to the present invention, comprising an acid functional group composed of IZM-2 zeolite, a hydrogenation functional group containing at least one noble metal from Group VIII of the periodic table selected from platinum and palladium, and a matrix.

[0101] In the catalyst obtained by the method of the present invention, the Group VIII metals are preferentially localized in and / or on the surface of the IZM-2 zeolite crystal, and the Group VIII metals are uniformly distributed on the catalyst.

[0102] The catalyst prepared according to the present invention may, advantageously, include at least one additional metal selected from the group formed by metals from Groups IIIA, IVA, and VIIB of the periodic table, preferably selected from gallium, indium, tin, and rhenium. The additional metal is preferably selected from indium, tin, and rhenium.

[0103] The catalyst also preferably includes sulfur.

[0104] The catalyst prepared according to the present invention more specifically comprises, and preferably consists of: - 1% to 50% by weight, preferably 2% to 30% by weight, and more preferably 5% to 20% by weight of IZM-2 zeolite according to the present invention, - 0.01% to 4% by weight, preferably 0.05% to 2% by weight, and more preferably 0.05% to 1% by weight, of at least one metal from Group VIII of the periodic table, preferably platinum, relative to the total mass of the catalyst. - Depending on the case, 0.01% to 2% by weight, preferably 0.05% to 1% by weight, of at least one additional metal selected from the group formed by metals from Group IIIA, Group IVA and Group VIIB. - Depending on the case, sulfur; preferably, the sulfur content should be such that the ratio of moles of sulfur to moles of Group VIII metals (one or more) is 0.3 to 20. - At least one matrix, preferably alumina, that provides the remainder to 100% in the catalyst.

[0105] (isomerization method) The subject of the present invention also relates to a method for isomerizing a paraffin-based feedstock, the method comprising placing the paraffin-based feedstock in at least contact with the catalyst according to the present invention present in a catalytic reactor.

[0106] According to the present invention, the paraffin-based feedstock used in the method according to the present invention is derived from renewable resources.

[0107] The paraffin in the paraffin-based supply raw material contains 9 to 25 carbon atoms, preferably 10 to 25, and very preferably 10 to 22 carbon atoms. The paraffin content in the supply raw material used in the method according to the present invention is advantageously more than 90% by weight, preferably more than 95% by weight, and even more preferably more than 98% by weight. Within the paraffin, the mass percentage of isoparaffin is less than 15%, preferably less than 10%, and very preferably less than 5%.

[0108] Preferably, the paraffinic feedstock is derived from renewable resources selected from vegetable oils, algae oils or algal oils, fish oils and fats of plant or animal origin, or mixtures of such feedstocks.

[0109] The vegetable oil may, advantageously, be entirely or partially crude or refined and may be derived from plants selected from rapeseed, sunflower, soybean, palm, olive, coconut, copra, castor oil plant, cotton, peanut oil, linseed oil and sea kale oil, and all oils obtained, for example, from sunflower or rapeseed through genetic modification or crossbreeding, but this list is not limited. The animal fat may, advantageously, be selected from fats consisting of fatty oils and fats consisting of residues from the food industry or residues arising from the food service industry. Frying oils, various animal oils, such as fish oil, animal fat and lard may also be used.

[0110] The original renewable resource from which the paraffinic feedstock used in the method according to the present invention is generated essentially comprises a triglyceride-type chemical structure, also known to those skilled in the art as fatty acid triesters, and free fatty acids having a fatty acid chain containing 9 to 25 carbon atoms.

[0111] The length and structure of the hydrocarbon chains of these fatty acids are compatible with those of gas oils and kerosenes, i.e., hydrocarbons present in the middle distillate fraction. Fatty acid triesters are therefore composed of three fatty acid chains. The number of unsaturated bonds per chain (also known as the number of carbon-carbon double bonds per chain) that these fatty acid chains have, in the form of triesters or free fatty acids, is between 0 and 3, but can be higher, particularly in oils derived from algae, which is generally 5 to 6 unsaturated bonds per chain.

[0112] The number of unsaturated molecules present in the renewable resources used in the present invention is expressed per triglyceride molecule and is preferably 0 to 18. In these raw materials, the degree of unsaturation is expressed as the number of unsaturated molecules per hydrocarbon fatty chain and is preferably 0 to 6.

[0113] Renewable resources generally contain various impurities, especially heteroatoms, such as nitrogen. The nitrogen content in vegetable oils is generally around 1 ppm by weight to 100 ppm by weight, depending on their properties. It may be up to 1% by weight for a particular supply.

[0114] The paraffin-based feedstock used in the method according to the present invention is, advantageously, derived from renewable resources by methods known to those skilled in the art. One possible method is the catalytic conversion of the renewable resources to a deoxygenated paraffin-based effluent in the presence of hydrogen, particularly hydrogenation.

[0115] Preferably, the paraffinic feedstock is produced by hydrogenation of the renewable resource. These methods for hydrogenation of renewable resources are well known and described in numerous patents. For example, the paraffinic feedstock used in the method according to the present invention may be advantageously produced from the renewable resource by hydrogenation, then gas / liquid separation, as described in patent FR 2 910 483 or patent FR 2 950 895.

[0116] The paraffinic feedstock used in the method according to the present invention may be a paraffinic feedstock produced by a method including an upgrade step via the Fischer-Tropsch route. In the Fischer-Tropsch method, synthesis gas (CO + H2) is catalytically converted in gaseous, liquid, or solid form into oxygenation products and essentially linear hydrocarbons. The resulting products constitute the feedstock for the method according to the present invention. Synthesis gas (CO + H2) is advantageously produced from any source of natural gas, coal, biomass, hydrocarbon-based compounds, or mixtures of these sources. Therefore, a paraffinic feedstock obtained from synthesis gas (CO + H2) produced from renewable resources, natural gas, or coal according to the Fischer-Tropsch synthesis method may be used in the method according to the present invention. Preferably, the paraffinic feedstock produced by Fischer-Tropsch synthesis and used in the method according to the present invention mainly contains n-paraffin. Therefore, the feedstock contains n-paraffin at a content of more than 60% by weight relative to the total mass of the feedstock. The supply material may contain, preferably, an oxygenated product in a content of less than 10% by weight, preferably an unsaturated substance in a content of less than 20% by weight, i.e., preferably an olefin product, and preferably an isoparaffin in a content of less than 10% by weight, relative to the total mass of the supply material.

[0117] Much more preferably, the supply material contains n-paraffin in a content of more than 70% by weight, and more preferably more than 80% by weight, relative to the total mass of the supply material. The paraffin in the paraffin-based supply material contains 9 to 25 carbon atoms, preferably 10 to 25, and very preferably 10 to 22 carbon atoms.

[0118] Preferably, the paraffin-based feedstock produced by the Fischer-Tropsch synthesis does not contain heteroatomic impurities, such as sulfur, nitrogen, or metals.

[0119] The isomerization method described above is generally carried out under the following operating conditions: - Temperature: 200°C to 500°C, preferably 210°C to 450°C, and more preferably 220°C to 430°C; - Partial pressure of hydrogen: 0.3 to 5.5 MPa, preferably 0.4 to 4.8 MPa; - Total pressure: 0.45~7MPa, preferably 0.6~6MPa; and - Feeding space velocity; expressed as the weight (kg) of feed material introduced per hour and per kilogram of catalyst weight (kg), from 0.25 to 30 hours. -1 Preferably 1 to 10 hours -1 , more preferably 2-6 hours -1 .

[0120] (List of drawings) Figure 1 shows the change in the local weight percentage of platinum for catalyst A, which does not conform to the present invention, according to the ratio of local weight %Al2O3 / (weight %Al2O3 + weight %IZM-2) obtained by Castan Microprobe.

[0121] Figure 2 shows the change in the local weight percentage of platinum for catalyst B, which conforms to the present invention, according to the ratio of local weight %Al2O3 / (weight %Al2O3 + weight %IZM-2) obtained by a Castan microprobe.

[0122] Figure 3 shows the change in the local weight percentage of platinum for catalyst C, which does not conform to the present invention, according to the ratio of local weight %Al2O3 / (weight %Al2O3 + weight %IZM-2) obtained by Castan Microprobe.

[0123] Figure 4 shows the change in the local weight percentage of platinum for catalyst D, which does not conform to the present invention, according to the ratio of local weight %Al2O3 / (weight %Al2O3 + weight %IZM-2) obtained by Castan Microprobe.

[0124] Figure 5 shows the change in the local weight percentage of platinum for catalyst E, which conforms to the present invention, according to the ratio of local weight %Al2O3 / (weight %Al2O3 + weight %IZM-2) obtained by a Castan microprobe.

[0125] Figure 6 shows the change in the local weight percentage of platinum for catalyst F, which does not conform to the present invention, according to the ratio of local weight %Al2O3 / (weight %Al2O3 + weight %IZM-2) obtained by Castan Microprobe.

[0126] Figure 7 shows the change in the local weight percentage of platinum for catalyst G, which does not conform to the present invention, according to the ratio of local weight %Al2O3 / (weight %Al2O3 + weight %IZM-2) obtained by Castan Microprobe.

[0127] The following examples illustrate the present invention, but do not limit its scope.

[0128] (Examples) (Example 1 (not conforming to the present invention): Preparation of isomerization catalyst A) (Synthesis of IZM-2 zeolite) IZM-2 zeolite was synthesized according to the teachings of patent FR 2 918 050 B. A colloidal silica suspension known under the trade name LudoxHS-40, sold by Aldrich, was incorporated into a solution composed of sodium hydroxide (Prolabo), 1,6-bis(methylpiperidinium)hexanedibromide as a structuring agent, aluminum hydroxide (Aldrich), and deionized water. The molar composition of the mixture was as follows: 1 SiO2; 0.0042 Al2O3; 0.1666 Na2O; 0.1666 1,6-bis(methylpiperidinium)hexane; 33.3333 H2O. The mixture was vigorously stirred for 30 minutes. The mixture was then transferred to a Pearl autoclave after homogenization. The autoclave was heated at 170°C with spindle stirring (30 rpm) for 5 days. The resulting product is filtered, washed with deionized water to a neutral pH, and then dried overnight in an oven at 100°C. The solid is then introduced into a muffle oven and calcined therein to remove the structuring agent. The calcination cycle includes increasing the temperature to 200°C, holding at this temperature for 2 hours, increasing the temperature to 550°C, holding at this temperature for 8 hours, and finally returning to ambient temperature. The temperature increase is carried out at a rate of 2°C / min. The solid thus obtained is then refluxed over 2 hours in an aqueous solution of ammonium nitrate (10 mL of solution per gram of solid weight, ammonium nitrate concentration 3 M) to exchange sodium alkali cations for ammonium ions. This refluxing step is repeated four times with fresh ammonium nitrate solution, and the solid is then filtered, washed with deionized water, and dried overnight in an oven at 100°C. Finally, the zeolite is acidified (protonated H) + To obtain the desired form, the firing process was carried out at 550°C for 10 hours (temperature increase rate of 2°C / min) in a transverse bed under dry air (2 standard liters per hour and per gram of solid weight). The resulting solid was analyzed by X-ray diffraction and identified as consisting of IZM-2 zeolite.

[0129] (IZM-2 / Preparation of alumina support (step i)) The IZM-2 / alumina support is obtained by kneading and extruding IZM-2 zeolite with alumina gel supplied by Axens. The kneaded paste is extruded through a 1.5 mm diameter tetrahedron die. After overnight drying in an oven at 110°C, the extruded material is calcined in a transverse bed under dry air (2 standard liters per hour and per gram of solid weight) for 2 hours at 520°C (temperature increase rate of 5°C / min). The weight content of IZM-2 zeolite on the support after calcination is 13% by weight.

[0130] (Platinum deposition (step ii), consistent with the present invention) Deposition is carried out by dry impregnation of the IZM-2 / alumina support prepared in step i) with an aqueous solution containing tetramineplatinum nitrate Pt(NH3)4(NO3)2. Typically, 20 g of the support is used and dry impregnated in a pan. After impregnation, the solid is allowed to mature in laboratory air for at least 5 hours, and then dried overnight in a ventilated oven at 110°C.

[0131] (ii) Heat treatment of the solid from (step iii), which does not conform to the present invention. After drying, the solid is then calcined in a tubular furnace under the following conditions, with a flow of dry air (the weight content of the gas is 23% by weight, the first gas mixture is chlorine-free and contains less than 0.001% by weight of moisture) per hour and per gram of solid weight: - Temperature increase from ambient temperature to 150°C at a rate of 5°C / min; - Hold at 150°C for 1 hour; - An increase of 5°C / min from 150°C to 450°C; - Holding at 450°C for 1 hour; - Decrease in ambient temperature.

[0132] At the end of step iii), various characterizations are performed on catalyst A. The Pt content measured by XRF is 0.34 wt%, and its distribution coefficient measured by Castan microprobe is 1.03.

[0133] Figure 1 shows the change in the local weight percentage of platinum in response to the local weight %Al2O3 / (weight %Al2O3 + weight %IZM-2) ratio obtained by the Castan microprobe. Locally, as the amount of alumina increases relative to the amount of IZM-2, the weight percentage of Pt decreases. This reflects the preferential deposition of platinum on the IZM-2 zeolite. Therefore, for the weight %Al2O3 / (weight %Al2O3 + weight %IZM-2) ratio which tends to approach 1, i.e., for analytical zones that do not contain IZM-2 zeolite, it is observed that the weight percentage of platinum tends to approach zero.

[0134] (Example 2 (conforms to the present invention): Preparation of isomerization catalyst B) (Synthesis of IZM-2 zeolite) This is the same zeolite as described in Example 1.

[0135] (IZM-2 / Preparation of alumina support (step i))) This is the same carrier as described in Example 1.

[0136] (Platinum deposition (step ii): Conforms to the present invention) This is the same deposit as described in Example 1.

[0137] (ii) Heat treatment of the solid (step iii), which is consistent with the present invention. After drying, the catalyst is then subjected to heat treatment in a tubular furnace at ambient temperature by contacting it with a first gas mixture consisting of dry air (the weight content of oxygen in the gas is 23% by weight, the first gas mixture does not contain chlorine, and contains less than 0.001% by weight of moisture) under the following conditions: - Under a flow of dry air (1 standard liter per hour and per gram of solid weight), the temperature increases from ambient temperature to 150°C at a rate of 5°C / min; - Holding at 150°C for 1 hour under a flow of dry air (1 standard liter per hour and per gram of solid weight); - Under a flow of dry air (1 standard liter per hour and per gram of solid weight), the temperature increases from 150°C to 450°C at a rate of 5°C / min; - Holding at 450°C for 1 hour under a flow of dry air (1 standard liter per hour and per gram of solid weight); - Under a flow of dry air (3.3 standard liters per hour and per gram of solid weight), the temperature was increased from 450°C to 520°C at a rate of 5°C / min.

[0138] At the start of holding at 520°C, water and dichloropropane are continuously injected into the first gas mixture to form a second gas mixture. The injection amounts correspond to a weight content of 2 wt% water and 0.63 wt% dichloropropane in the gas mixture. The temperature is maintained at 520°C for 4 hours. The temperature is then lowered from 520°C to 400°C at a rate of 5°C / min, still under the second gas mixture. At 400°C, the injection of water and dichloropropane is stopped, and the solid is cooled to ambient temperature under a flow of dry air (3.3 standard liters per hour and per gram of weight of solid).

[0139] At the end of step iii), various characterizations are performed on catalyst B. The Pt content measured by XRF is 0.34 wt%, and its distribution coefficient measured by Castan microprobe is 1.03.

[0140] Figure 2 shows the change in the local weight percentage of platinum according to the local wt %Al2O3 / (wt %Al2O3 + wt %IZM-2) ratio obtained by the Castan microprobe. It should be noted that, as in the case of catalyst A, locally, the weight percentage of Pt decreases as the amount of alumina increases relative to the amount of IZM-2. This reflects the preferential deposition of platinum on the IZM-2 zeolite.

[0141] (Example 3 (not conforming to the present invention): Preparation of isomerization catalyst C) (Synthesis of IZM-2 zeolite) This is the same zeolite as described in Example 1.

[0142] (IZM-2 / Preparation of alumina support (step i))) The IZM-2 / alumina support is obtained by kneading and extruding IZM-2 zeolite with alumina gel supplied by Axens. The kneaded paste is extruded through a 1.5 mm diameter tetrahedron die. After overnight drying in an oven at 110°C, the extruded material is calcined on a transverse bed under dry air (2 standard liters per hour and per gram of solid weight) for 2 hours at 550°C (temperature increase rate of 5°C / min). The weight content of IZM-2 zeolite on the support after calcination is 13% by weight.

[0143] (Platinum deposition (step ii), consistent with the present invention) Deposition is carried out by dry impregnation of the IZM-2 / alumina support prepared in step i) with an aqueous solution containing tetramineplatinum nitrate (Pt(NH3)4(NO3)2). Typically, 20 g of the support is used and dry impregnated in a pan. After impregnation, the solid is allowed to mature in laboratory air for at least 5 hours, and then dried overnight in a ventilated oven at 110°C.

[0144] (ii) Heat treatment of the solid from (step iii), which does not conform to the present invention.) After drying, the solid is then calcined in a tubular furnace under the following conditions, with a flow of dry air (the weight content of oxygen in the gas is 23% by weight, the dry air does not contain chlorine, and contains less than 0.001% by weight of moisture) per hour and per gram of solid weight: - Temperature increase from ambient temperature to 150°C at a rate of 5°C / min; - Hold at 150°C for 1 hour; - An increase of 5°C / min from 150°C to 450°C; - Holding at 450°C for 1 hour; - Decrease in ambient temperature.

[0145] At the end of step iii), various characterizations are performed on catalyst C. The Pt content measured by XRF is 0.26 wt%, and its distribution coefficient measured by Castan microprobe is 1.00.

[0146] Figure 3 shows the change in local weight percentage of platinum in response to the local weight %Al2O3 / (weight %Al2O3 + weight %IZM-2) ratio obtained by the Castan microprobe. Locally, as the amount of alumina increases relative to the amount of IZM-2, the weight percentage of Pt decreases, which reflects the preferential deposition of platinum on IZM-2 zeolite. For the weight %Al2O3 / (weight %Al2O3 + weight %IZM-2) ratio that tends towards 1, i.e., the analytical zone that does not contain any IZM-2 zeolite, it is therefore observed that the weight percentage of platinum tends towards zero.

[0147] (Example 4 (conforms to the present invention): Preparation of isomerization catalyst D) (Synthesis of IZM-2 zeolite) This is the same zeolite as described in Example 1.

[0148] (IZM-2 / Preparation of alumina support (step i))) This is the same carrier as described in Example 3.

[0149] (Platinum deposition (step ii), consistent with the present invention) This is the same deposit as described in Example 3.

[0150] (ii) Heat treatment of the solid (step iii), which is consistent with the present invention. After drying, the catalyst is then subjected to heat treatment in a tubular furnace at ambient temperature, by contacting it with a first gas mixture of dry air (the weight content of oxygen in the gas is 23% by weight, the first gas mixture does not contain chlorine, and contains less than 0.001% by weight of moisture) under the following conditions: - Under a flow of dry air (1 standard liter per hour and per gram of solid weight), the temperature increases from ambient temperature to 150°C at a rate of 5°C / min; - Holding at 150°C for 1 hour under a flow of dry air (1 standard liter per hour and per gram of solid weight); - Under a flow of dry air (1 standard liter per hour and per gram of solid weight), the temperature increases from 150°C to 450°C at a rate of 5°C / min; - Holding at 450°C for 1 hour under a flow of dry air (1 standard liter per hour and per gram of solid weight); - Under a flow of dry air (3.3 standard liters per hour and per gram of solid weight), the temperature was increased from 450°C to 520°C at a rate of 5°C / min.

[0151] At the start of holding at 520°C, water and dichloropropane are continuously injected into the first gas mixture to form a second gas mixture. The injection amounts correspond to a weight content of 2 wt% water and 0.63 wt% dichloropropane in the gas mixture. The temperature is maintained at 520°C for 4 hours. The temperature is then lowered from 520°C to 400°C at a rate of 5°C / min, still under the second gas mixture. At 400°C, the injection of water and dichloropropane is stopped, and the solid is then cooled to ambient temperature under a flow of dry air (3.3 standard liters per hour and per gram of solid weight).

[0152] At the end of step iii), various characterizations are performed on catalyst D. The Pt content measured by XRF is 0.25 wt%, and its distribution coefficient measured by Castan microprobe is 0.99.

[0153] Figure 4 shows the change in the local weight percentage of platinum in response to the local wt%Al2O3 / (wt%Al2O3+wt%IZM-2) ratio obtained by the Castan microprobe. It is noted that, as in the case of catalyst A, locally, the weight percentage of Pt decreases as the amount of alumina increases relative to the amount of IZM-2, which reflects the preferential deposition of platinum on the IZM-2 zeolite. Therefore, it is observed that the weight percentage of platinum tends to move towards zero in the wt%Al2O3 / (wt%Al2O3+wt%IZM-2) ratio that tends towards 1, i.e., in the analytical zone that does not contain any IZM-2 zeolite.

[0154] (Example 5 (conforms to the present invention): Preparation of isomerization catalyst E) (Synthesis of IZM-2 zeolite) This is the same zeolite as described in Example 1.

[0155] (IZM-2 / Preparation of alumina support (step i))) This is the same carrier as described in Example 3.

[0156] (Platinum deposition (step ii), consistent with the present invention) This is the same deposit as described in Example 3.

[0157] (ii) Heat treatment of the solid (step iii), which is consistent with the present invention. After drying, the catalyst is then subjected to heat treatment in a tubular furnace at ambient temperature by contacting it with a first gas mixture of dry air (3.3 standard liters per hour and per gram of solid weight) (the weight content of oxygen in the gas is 23% by weight, the first gas mixture does not contain chlorine and contains less than 0.001% by weight of moisture). The temperature is raised from ambient temperature to 520°C at a rate of 5°C / min.

[0158] At the start of holding at 520°C, water and dichloropropane are continuously injected into the first gas mixture in addition to a flow of dry air to form a second gas mixture. The injection amounts correspond to a weight content of 2 wt water and 0.63 wt dichloropropane in the gas mixture. The temperature is maintained at 520°C for 4 hours. The temperature is then lowered from 520°C to 400°C at a rate of 5°C / min, still under the second gas mixture. At 400°C, the injection of water and dichloropropane is stopped, and the solid is cooled to ambient temperature under a flow of dry air (3.3 standard liters per hour and per gram of solid weight).

[0159] At the end of step iii), various characterizations are performed on catalyst E. The Pt content measured by XRF is 0.25 wt%, and its distribution coefficient measured by Castan microprobe is 1.00.

[0160] Figure 5 shows the change in the local weight percentage of platinum according to the local weight %Al2O3 / (weight %Al2O3 + weight %IZM-2) ratio obtained by the Castan microprobe. It is noted that, as with catalyst A, locally, as the amount of alumina increases relative to the amount of IZM-2, the weight percentage of Pt decreases, which reflects the preferential deposition of platinum on the IZM-2 zeolite. Therefore, it is observed that the weight percentage of platinum tends to approach zero in the weight %Al2O3 / (weight %Al2O3 + weight %IZM-2) ratio, i.e., in the analytical zone that does not contain any IZM-2 zeolite.

[0161] (Example 6 (not consistent with the present invention): Preparation of isomerization catalyst F) (Synthesis of IZM-2 zeolite) This is the same zeolite as described in Example 1.

[0162] (IZM-2 / Preparation of alumina support (step i))) This is the same carrier as described in Example 3.

[0163] (Platinum deposition (Step ii), not in accordance with the present invention)) The preparation of Catalyst F is carried out by impregnating the IZM-2 / alumina support with an aqueous solution containing hexachloroplatinic acid, which is a platinum precursor not in accordance with the present invention, in an excessive amount. The concentration of hexachloroplatinic acid in the solution is 1.28×10 -3 mol / L.

[0164] Using 20 g of the support, the pore volume of the support is filled with distilled water, and the solid is allowed to stand and age at ambient temperature for 1 hour. The solid is then immersed in 80 mL of a hydrochloric acid HCl solution with a concentration of 3.52×10 -1 mol / L in an Erlenmeyer flask, and then the whole is stirred on a stirrer (100 rpm) at ambient temperature for 1 hour. Then, the hydrochloric acid solution is removed, and the solid is immersed in 80 mL of the above-mentioned hexachloroplatinic acid solution, and then the whole is stirred on a shaker (100 rpm) at ambient temperature for 24 hours. Then, the impregnation solution is removed, and the solid is rinsed with 160 mL of distilled water. The solid is then dried overnight at 110 °C in a ventilated oven.

[0165] (Heat treatment of the solid from (ii) (Step iii), not in accordance with the present invention)) After drying, the solid is then fired in a tubular furnace under the following conditions in a cross-flow bed under a flow of dry air (the weight content of oxygen in the gas is 23% by weight, and the dry air does not contain chlorine and contains less than 0.001% by weight of moisture) (1 standard liter per hour and per gram of the weight of the solid): - Temperature increase from ambient temperature to 150 °C at 5 °C / min; - Holding at 150 °C for 1 hour; - Increase from 150 °C to 450 °C at 5 °C / min; - Holding at 450 °C for 1 hour; - Decrease to ambient temperature.

[0166] At the end of step iii), various characterizations are performed on catalyst F. The Pt content measured by XRF is 0.11 wt%, and its distribution coefficient measured by Castan microprobe is 1.01.

[0167] Figure 6 shows the change in the local weight percentage of platinum as a function of the local wt%Al2O3 / (wt%Al2O3+wt%IZM-2) ratio obtained by the Castan microprobe. In contrast to catalysts A, B, C, D, and E, it is noted that locally, the weight percentage of Pt tends to increase as the amount of alumina increases relative to the amount of IZM-2. This reflects the preferential deposition of IZM-2.

[0168] (Example 7 (not consistent with the present invention): Preparation of isomerization catalyst G) (Synthesis of IZM-2 zeolite) This is the same zeolite as described in Example 1.

[0169] (IZM-2 / Preparation of alumina support (step i))) This is the same carrier as described in Example 6.

[0170] (Platinum deposition (step ii), not in accordance with the present invention) This is the same deposition as described in Example 6, which uses a platinum precursor that does not conform to the present invention.

[0171] (ii) Heat treatment of the solid (step iii), which is consistent with the present invention. After drying, the catalyst is then subjected to heat treatment by contacting it with a first gas mixture of dry air (the weight content of oxygen in the gas is 23% by weight, the first gas mixture does not contain chlorine and contains less than 0.001% by weight of moisture) in a tubular furnace at ambient temperature under the following conditions: - Under a flow of dry air (1 standard liter per hour and per gram of solid weight), the temperature increases from ambient temperature to 150°C at a rate of 5°C / min; - Holding at 150°C for 1 hour under a flow of dry air (1 standard liter per hour and per gram of solid weight); - Under a flow of dry air (1 standard liter per hour and per gram of solid weight), the temperature increases from 150°C to 450°C at a rate of 5°C / min; - Holding at 450°C for 1 hour under a flow of dry air (1 standard liter per hour and per gram of solid weight); - Under a flow of dry air (3.3 standard liters per hour and per gram of solid weight), the temperature was increased from 450°C to 520°C at a rate of 5°C / min.

[0172] At the start of holding at 520°C, water and dichloropropane are continuously injected into the flow of dry air to form a second gas mixture. The injection amounts correspond to a weight content of 2 wt% water and 0.63 wt% dichloropropane in the gas mixture. The temperature is maintained at 520°C for 4 hours. The temperature is then lowered from 520°C to 400°C at a rate of 5°C / min, still under the second gas mixture. At 400°C, the injection of water and dichloropropane is stopped, and the solid is cooled to ambient temperature under a flow of dry air (3.3 standard liters per hour and per gram of solid weight).

[0173] At the end of step iii), various characterizations are performed on catalyst G. The Pt content measured by XRF is 0.10 wt%, and its distribution coefficient measured by Castan microprobe is 1.04.

[0174] Figure 7 shows the change in the local weight percentage of platinum as a function of the local wt %Al2O3 / (wt %Al2O3 + wt %IZM-2) ratio obtained by the Castan microprobe. It is noted that, in contrast to catalysts A, B, C, D, and E, locally, the weight percentage of Pt tends to increase as the amount of alumina increases relative to the amount of IZM-2. This reflects the preferential deposition of platinum on alumina.

[0175] (Example 8: Evaluation of catalytic properties of catalyst in isomerization of paraffin-based feedstock) The catalyst was tested in the isomerization of a paraffinic feedstock composed of n-hexadecane. The tests were conducted in a microunit operating in a downward flow without recycling using a fixed-bed reactor. Hydrocarbon-based effluents were analyzed online by gas chromatography. Once loaded into the unit, the catalyst underwent a first step of drying under nitrogen under the following conditions: - Nitrogen flow rate: 2 standard liters per hour and per gram of catalyst weight, - Total pressure: 0.1 MPa, - Temperature increase rate from ambient temperature to 150°C: 5°C / min - Hold at 150°C for 30 minutes.

[0176] After drying, nitrogen is replaced with hydrogen, and then the reduction process is carried out under the following conditions, under a flow of high-purity hydrogen: - Hydrogen flow rate: 5 standard liters per hour and per gram of catalyst weight. - Total pressure: 1.1 MPa, - Temperature increase rate from 150°C to 450°C: 5°C / min - Hold at 450°C for 1 hour.

[0177] After the reduction step, the temperature is lowered to 230°C, and the catalyst is placed in contact with n-hexadecane under the following conditions: - Feeding space velocity: per hour and per weight (grams) of catalyst, n-hexadecane 2g - Molar ratio of hydrogen to n-hexadecane: 10, - Total pressure: 1.1 MPa.

[0178] The conversion is modified by changing the temperature; two analyses of the effluent are performed at each temperature hold, allowing for the calculation of catalytic performance and checking the stability of catalytic performance for the temperature hold. Typically, the temperature is varied between 230°C and 350°C with a 5°C temperature hold. The effluent analysis is performed collectively using an online GC system. The temperature required to reach a 50% conversion rate serves as a descriptor of the catalyst's activity, while the maximum yield of the resulting hexadecane isomer serves as a descriptor of the catalyst's isomerization properties. The yields of methane and ethane at 310°C are used as descriptors of the catalyst's hydrocracking activity.

[0179] Table 1 therefore reports the catalytic performance of the catalyst in the hydrogenation conversion of n-hexadecane.

[0180] [Table 1]

[0181] Catalysts A and B were prepared from the same IZM-2 / alumina support, and the Pt deposition procedure for both solids conforms to the present invention. However, the heat treatment after Pt deposition on catalyst A does not conform to the present invention. These catalysts have equivalent catalytic activity (a difference of 1 degree in activity), but catalyst B, treated according to the present invention, is observed to have a higher maximum isomerization yield. Catalyst B also has lower hydrocracking activity than catalyst A at 310°C, as the yields of methane and ethane are reduced to one-third.

[0182] Catalysts C, D, and E are prepared from the same IZM-2 / alumina support. For these three solids, the deposition of Pt conforms to the present invention, but the heat treatment after Pt deposition on catalyst C does not conform to the present invention. Catalysts D and E, which conform to the present invention, are observed to have better activity (a difference of 3 degrees). Catalysts D and E also have higher maximum isomerization yields than catalyst C. Catalysts D and E also have lower hydrocracking activity than catalyst C at 310°C, as the yields of methane and ethane are reduced to one-third and one-fourth and fifth, respectively.

[0183] Finally, catalysts F and G are prepared from the same IZM-2 / alumina support as catalysts C, D, and E. However, the Pt deposition procedure for these two catalysts is not in accordance with the present invention. The heat treatment of catalyst F after Pt deposition is not in accordance with the present invention, while the heat treatment of catalyst G is in accordance with the present invention. In this case, it is observed that the heat treatment in accordance with the present invention does not improve the maximum isomerization yield, and this is the same for both catalysts. Similarly, the yields of methane and ethane remain the same for both catalysts. Finally, it is observed that the maximum isomerization yields of catalysts F and G, which are not in accordance with the present invention, are significantly lower than the maximum isomerization yields obtained with catalysts D and E, which are prepared from the same IZM-2 / alumina support as catalysts F and G, and are in accordance with the present invention.

[0184] Therefore, it should be noted that for catalysts conforming to the present invention that have both preferential localization of Pt on or in the zeolite and a heat treatment conforming to the present invention, a systematic improvement in the maximum isomerization yield is observed, and this is clearly related to a decrease in the hydrocracking activity of the catalyst. [Brief explanation of the drawing]

[0185] [Figure 1] This shows the change in the local weight percentage of platinum according to the local wt%Al2O3 / (wt%Al2O3+wt%IZM-2) ratio obtained by Castan Microprobe for catalyst A, which does not conform to the present invention. [Figure 2] This shows the change in the local weight percentage of platinum according to the local wt%Al2O3 / (wt%Al2O3+wt%IZM-2) ratio obtained by Castan Microprobe for catalyst B, which conforms to the present invention. [Figure 3] This shows the change in the local weight percentage of platinum according to the local wt%Al2O3 / (wt%Al2O3+wt%IZM-2) ratio obtained by Castan Microprobe for catalyst C that does not conform to the present invention. [Figure 4]This shows the change in the local weight percentage of platinum according to the local wt%Al2O3 / (wt%Al2O3+wt%IZM-2) ratio obtained by Castan Microprobe for catalyst D, which does not conform to the present invention. [Figure 5] This shows the change in the local weight percentage of platinum according to the local wt%Al2O3 / (wt%Al2O3+wt%IZM-2) ratio obtained by Castan Microprobe for catalyst E conforming to the present invention. [Figure 6] This shows the change in the local weight percentage of platinum according to the local wt%Al2O3 / (wt%Al2O3+wt%IZM-2) ratio obtained by Castan Microprobe for catalyst F that does not conform to the present invention. [Figure 7] This shows the change in the local weight percentage of platinum according to the local wt%Al2O3 / (wt%Al2O3+wt%IZM-2) ratio obtained by Castan Microprobe for catalyst G which does not conform to the present invention.

Claims

1. A method for preparing a bifunctional catalyst comprising an acid functional group composed of IZM-2 zeolite, a hydrogenation functional group containing at least one precious metal from Group VIII of the periodic table selected from platinum and palladium, and a matrix, the method comprising at least the following steps: i) A step of preparing a support for the catalyst by shaping IZM-2 zeolite with a matrix; such that the weight percentage of the zeolite is 2% to 30% relative to the weight of the support. ii) A step of depositing at least one noble metal from Group VIII of the periodic table by impregnating a carrier prepared in step i) that enables the acquisition of a solid with an aqueous solution containing at least the following compounds: - A platinum (II) tetramine salt of the formula Pt(NH ７ , ２ , ３ , ２ , ５ , ４ )(OH ４ ), a platinum (II) tetramine salt of the formula Pt(NH ３ )(NO ３ )(OH ４ ), or a platinum (II) tetramine salt of the formula Pt(NH ３ )(NO ２ ); a platinum (IV) hexamine salt of the formula Pt(NH ３ )(NO ４ )(OH ２ ); a platinum (IV) halopentamine salt of the formula (PtX(NH ３ )(OH ５ ))(NO ３ ); a platinum N-tetrahalodiamine salt of the formula PtX ４ (NH ３ )(OH ２ ); at least one ammonia-based compound selected from platinum N-tetrahalodiamine salts of the formula PtX ４ (NH ３ )(OH ２ ); and a halogenated compound of the formula H(Pt(acac ２ )(OH ３ )); a palladium (II) salt Pd(NH ４ )(SO ４ ), or Pd(NH ３ )(OH ４ ); wherein X is a halogen selected from chlorine, fluorine, bromine, and iodine, and "acac" represents an acetylacetonate group (of the empirical formula C ５ H ７ O ２ ), and is a compound derived from acetylacetone.​​ iii) At least one heat treatment step; the solid prepared in step ii) is brought into contact with at least one gas mixture containing oxygen, water, chlorine and / or at least one chlorinated compound, and the heat treatment step is carried out at 200°C to 1100°C.

2. The method according to claim 1, wherein step i) is performed by kneading and extrusion.

3. The method according to claim 1 or 2, wherein the matrix used in step i) is alumina.

4. The method according to any one of claims 1 to 3, wherein the carrier obtained at the end of step i) is subjected to a drying step carried out at a temperature of 50°C to 180°C.

5. The method according to any one of claims 1 to 4, wherein X is chlorine.

6. The aqueous solution from step ii) is given by formula Pt(NH ３ ) ４ (OH) ２ , Pt(NH ３ ) ４ (NO ３ ) or Pt(NH ３ ) ４ X ２ Platinum(II) tetramine salt, formula Pt(NH ３ ) ６ X ４ Platinum (IV) hexamine salt; formula (PtX(NH) ３ ) ５ ) X ３ Platinum(IV) halopentamine salt; formula PtX ４ (NH ３ ) ２ Ammonia-based compounds selected from platinum N-tetrahalodiamine salts; and formula H(Pt(acac) ２ The method according to any one of claims 1 to 5, comprising a halogenated compound of X); X and "acac" having the meanings described above.

7. The aforementioned solution is Pt(NH ３ ) ４ (OH) ２ , Pt(NH ３ ) ４ (NO ３ ) or Pt(NH ３ ) ４ X ２ The method according to claim 6, comprising an ammonia-based compound selected from platinum(II) tetramine salts.

8. The impregnation solution is ammonium nitrate NH ４ NO ３ , ammonium chloride NH ４ Cl, ammonium sulfate (NH ４ ) ２ SO ４ , ammonium hydroxide NH ４ OH, Ammonium bicarbonate NH ４ HCO ３ and ammonium acetate NH ４ H ３ C ２ O ２ The method according to any one of claims 1 to 7, further comprising at least one ammonium salt that does not contain a precious metal, selected from the above, either alone or as a mixture.

9. The method according to claim 8, wherein the molar ratio between the ammonium salt and the noble metal is 0.1 to 400.

10. The method according to any one of claims 1 to 9, wherein the heat treatment in step iii) is carried out at a temperature greater than 300°C and less than 700°C.

11. The method according to any one of claims 1 to 10, wherein the chlorinated compound is a chlorinated compound selected from inorganic or organic carbon tetrachloride, dichloropropane, dichloroethane, and chloroform.

12. The method according to any one of claims 1 to 11, wherein the step of contacting the solid from step ii) with a gas containing oxygen but not containing chlorine and / or at least one chlorinated compound is used between step ii) and the heat treatment step iii) until a desired temperature for carrying out step iii) is reached.

13. The method according to claim 12, wherein the temperature for carrying out step iii) is greater than 300°C and less than 700°C.

14. A catalyst comprising an acid functional group composed of IZM-2 zeolite, a hydrogenation functional group containing at least one noble metal from Group VIII of the periodic table selected from platinum and palladium, and a matrix, obtained by the method according to any one of claims 1 to 13.

15. A method for isomerizing a paraffinic feedstock containing 9 to 25 carbon atoms, comprising placing the paraffinic feedstock in at least contact with the catalyst described in claim 14, wherein the temperature during the method is 200°C to 500°C, the partial pressure of hydrogen is 0.3 to 5.5 MPa, the total pressure is 0.45 to 7 MPa, and the feeding space velocity is 0.25 to 30 h, expressed as the weight of feedstock introduced per kilogram of catalyst and per hour. －１ The method.

16. The method according to claim 15, wherein the paraffin-based feedstock is derived from renewable resources selected from vegetable oils, algal oils, fish oils, and fats of plant or animal origin, or mixtures of such feedstocks.

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