阅读说明：本技术 碳化物基催化剂及其制备方法以及环烷烃氢解开环方法 (Carbide-based catalyst, preparation method thereof and naphthenic hydrocarbon hydrogenolysis ring-opening method ) 是由 郑仁垟 徐柏庆 董笑 郑爱国 李会峰 李明丰 夏国富 晋超 于 2018-09-07 设计创作，主要内容包括：本公开涉及一种碳化物基催化剂及其制备方法以及环烷烃氢解开环方法,该催化剂包括载体、第一活性组分、以及第二活性组分,所述第一活性组分为第一活性金属Ir或Rh,所述第二活性组分为第二活性金属M的碳化物和氧化物的复合体MC<Sub>x</Sub>-MO<Sub>y</Sub>,其中M为选自第IVB族、第VB族和第VIB族金属中的一种,x＝0.5～1,y＝1.5～3。与现有技术制备的相同活性金属含量的催化剂相比,本公开的碳化物基催化剂表现出优异的催化环烷烃氢解开环活性,直链烷烃选择性高。(The present disclosure relates to a carbide-based catalyst, a preparation method thereof and a ring opening method for hydrogenolysis of cycloalkanes, the catalyst comprises a carrier, a first active component and a second active component, wherein the first active component is a first active metal Ir or Rh, and the second active component is a complex MC of a carbide and an oxide of a second active metal M x ‑MO y Wherein M is one selected from metals of IVB group, VB group and VIB group, x is 0.5-1, and y is 1.5-3. Compared with the catalyst with the same active metal content prepared by the prior art, the carbide-based catalyst disclosed by the invention has excellent catalytic ring opening activity for hydrogenolysis of cycloalkane and high linear alkane selectivity.)

1. A carbide-based catalyst comprising a support, a first active component which is a first active metal Ir or Rh, and a second active component which is a composite MC of a carbide and an oxide of a second active metal M_x-MO_yWherein M is one selected from metals of IVB group, VB group and VIB group, x is 0.5-1, and y is 1.5-3.

2. The catalyst of claim 1, wherein the catalyst satisfies (M)_MCx/M_MOy)_XPS0.1 to 20, preferably, (M)_MCx/M_MOy)_XPS1 to 10, wherein (M)_MCx/M_MOy)_XPSMC in terms of metal element M in the catalyst characterized by X-ray photoelectron spectroscopy_xAnd MO_yIn a weight ratio of (a).

3. The catalyst according to claim 1, wherein the second active metal M is Mo, W, Ti, Zr or Nb.

4. The catalyst of claim 1, wherein the first active component is present in an amount of 0.01 to 10 wt%, the second active component is present in an amount of 2 to 80 wt%, and the carrier is present in an amount of 10 to 97 wt%, calculated as the metal element and based on the weight of the catalyst on a dry basis;

preferably, the content of the first active component is 0.1-5 wt%, the content of the second active component is 5-50 wt%, and the content of the carrier is 45-94 wt% calculated on the metal element and based on the dry weight of the catalyst.

5. The catalyst of claim 1 wherein the support is alumina, silica, titania, magnesia, zirconia, thoria, beryllia, clay, molecular sieve or activated carbon, or a combination of two or three thereof.

6. A method of preparing a carbide-based catalyst, the method comprising the steps of:

a. loading a first active metal and a second active metal on a carrier through impregnation to obtain an impregnated material;

b. carbonizing the impregnated material obtained in the step a in a carbon-containing compound atmosphere to obtain a carbonized material;

c. b, oxidizing the carbonized material obtained in the step b in an oxygen-containing compound atmosphere;

wherein the first active metal is Ir or Rh; the second active metal is one selected from group IVB, group VB and group VIB metals.

7. The method according to claim 6, wherein in step a, the weight ratio of the first active metal, the second active metal, and the carrier on a dry basis, calculated as the metal element, is (0.0001-1): (0.021-8): 1, preferably (0.0011 to 0.11): (0.053-1.1): 1;

and/or, the impregnation conditions include: the temperature is 10-90 ℃, and preferably 15-40 ℃; the time is 1-10 h, preferably 2-6 h.

8. The method of claim 6, wherein the method further comprises: drying and roasting the impregnated material obtained in the step a, and then performing the operation of the step b; and/or, the drying conditions are as follows: the temperature is 80-150 ℃, and the time is 1-24 h; and/or the roasting conditions are as follows: the temperature is 200-700 ℃, and the time is 1-12 h.

9. The process of claim 6, wherein in step b, the carbon-containing compound is carbon monoxide, methane, ethane, ethylene, acetylene, propane, propylene, or propyne, or a combination of two or three thereof; and/or, in the atmosphere containing the carbon compound, the content of the carbon compound is 5-50% by volume, preferably 10-25% by volume;

and/or, the carbonization conditions comprise: the temperature is 300-1000 ℃, preferably 500-900 ℃; the time is 1-24 h, preferably 2-12 h.

10. The method of claim 6, wherein the method further comprises: and c, cooling the carbonized material obtained in the step b to below 50 ℃ in the atmosphere of the carbon-containing compound, the hydrogen gas or the inert atmosphere, treating the material in the inert atmosphere for 0.2-24 h, and then performing the operation in the step c.

11. The process of claim 6, wherein in step c, the oxygenate is oxygen, carbon dioxide or water vapor, or a combination of two or three thereof; and/or, in the oxygen-containing compound atmosphere, the content of the oxygen-containing compound is 0.01-15% by volume, preferably 0.1-10% by volume;

and/or, the oxidation conditions include: the temperature is 100-800 ℃, and preferably 250-550 ℃; the time is 1-24 h, preferably 2-12 h.

12. The method of claim 6, wherein the second active metal is Mo, W, Ti, Zr, or Nb;

and/or the carrier is alumina, silica, titania, magnesia, zirconia, thoria, beryllia, clay, molecular sieve or activated carbon, or the combination of two or three of the above.

13. A carbide-based catalyst prepared by the method of any one of claims 6 to 12.

14. A method for hydrogenolysis ring opening of cycloalkane, comprising contacting a feedstock containing cycloalkane, hydrogen gas and a catalyst under conditions to catalyze hydrogenolysis ring opening of cycloalkane, wherein the catalyst is the carbide-based catalyst of any one of claims 1 to 5 and 13.

15. The method of claim 14, wherein the conditions that catalyze the hydrogenolysis ring opening of cycloalkanes comprise: the temperature is 180-450 ℃, preferably 220-400 ℃; the pressure is 1-18 MPa, preferably 2-12 MPa; the volume ratio of the hydrogen to the oil is 50-10000, preferably 50-5000; the mass space velocity is 0.1-100 h^-1Preferably 0.2 to 80 hours^-1。

Technical Field

The disclosure relates to a carbide-based catalyst, a preparation method thereof and a naphthenic hydrocarbon hydrogenolysis ring-opening method.

Background

With the development of the world economy, the demand of diesel oil is increasing. This requirement cannot be met by straight-run diesel alone, which requires blending in secondary process diesel, such as catalytic cracking diesel and coker diesel. The secondary processing diesel contains a large amount of sulfur, nitrogen and aromatic hydrocarbon, the sulfur and the nitrogen can be removed by using the traditional sulfide catalyst at present, and the technical difficulty is the conversion of the aromatic hydrocarbon. The high aromatics content in diesel fuel not only reduces the quality of the oil, but also increases particulate emissions in the combustion exhaust of diesel fuel. Normally normal or short-side chain paraffins have the highest cetane number, long-side chain paraffins and aromatics are higher in cetane number, and short-side chain or side chain-free naphthenes and aromatics are the lowest in cetane number. Thus, the aromatics hydrogenation saturation process is limited to increasing the cetane number of diesel fuel, and the ring-opening reaction is expected to increase the cetane number of diesel fuel. With the increasing severity of environmental regulations on clean energy, dearomatization upgrading of diesel fuels has become a focus of research. Therefore, the realization of the high-selectivity ring-opening reaction of the cyclanes has important significance for improving the quality of the diesel oil.

The cycloalkane ring-opening reaction can proceed by three mechanisms: a radical reaction mechanism, a carbonium ion mechanism and a hydrogenolysis mechanism (Journal of Catalysis,2002,210, 137-148). In contrast, metal catalyzed hydrogenolysis mechanisms have higher activity and selectivity for selective ring opening of cycloalkanes, primarily because ring opening is easier than side chain scission due to the intra-ring tension of the cycloalkane molecule.

WO/2002/007881 discloses a catalyst and process for ring opening of cycloalkanes by use of iridium catalysts supported on a composite support of alumina and an acidic aluminosilicate molecular sieve. Moreover, the catalyst is exposed to oxygen atmosphere of 250 ℃ for calcination and regeneration, and the ring-opening activity of the catalyst is not significantly deactivated.

CN200480043382.0 discloses a catalyst and a method for opening cyclic alkane using the catalyst. The catalyst comprises a group VIII metal component, a molecular sieve, a refractory inorganic oxide, and optionally a modifier component. The molecular sieves include MAPSO, SAPO, UZM-8 and UZM-15, the group VIII metals include platinum, palladium and rhodium, and the inorganic oxide is preferably alumina.

CN200910013536.6 discloses a naphthenic hydrocarbon hydroconversion catalyst, a preparation method and application thereof. The catalyst comprises a carrier and active metal Pt, wherein the carrier consists of a hydrogen type Y-Beta composite molecular sieve and an inorganic refractory oxide, the content of the hydrogen type Y-Beta composite molecular sieve in the catalyst carrier is 10-90 wt%, and the content of the active metal Pt in the catalyst is 0.05-0.6%. The catalyst is prepared by adopting an impregnation method, and the obtained catalyst can be used for the hydro-conversion of various raw materials containing cycloparaffin.

CN201110102568.0 discloses an aromatic selectivity ring-opening reaction process, wherein the reaction is carried out in two reactors connected in series; the material enters a first reactor for deep desulfurization and denitrification reaction and passes through H₂S and NH₃Separating the sulfur and the nitrogen by a separation device, and when the S content in the material is lower than 50ppm and the N content is lower than 10ppm, feeding the material into a second reactor for selective ring-opening reaction, wherein the reactor is provided with two reaction beds, the first reaction bed is used for hydrogenation saturation isomerization reaction, and the second reaction bed is used for selective ring-opening reaction; the first reactor selects a metal sulfide catalyst; the first bed of the second reactor is filled with a noble metal/molecular sieve-alumina catalyst.

However, there is still room for improvement and improvement in the naphthene hydrogenolysis ring-opening activity and selectivity of the above-disclosed catalysts.

Disclosure of Invention

The purpose of the disclosure is to provide a carbide-based catalyst, a preparation method thereof and a naphthenic hydrocarbon hydrogenolysis ring-opening method, wherein the catalyst has higher naphthenic hydrocarbon hydrogenolysis ring-opening activity and straight-chain alkane selectivity.

In order to achieve the above object, the present disclosure provides a carbide-based catalyst comprising a support, a first active component which is a first active metal Ir or Rh, and a second active component which is a complex MC of a carbide and an oxide of a second active metal M_x-MO_yWherein M is one selected from metals of IVB group, VB group and VIB group, x is 0.5-1, and y is 1.5-3.

Optionally, wherein the catalyst satisfies (M)_MCx/M_MOy)_XPS0.1 to 20, preferably, (M)_MCx/M_MOy)_XPS1 to 10, wherein (M)_MCx/M_MOy)_XPSMC in terms of metal element M in the catalyst characterized by X-ray photoelectron spectroscopy_xAnd MO_yIn a weight ratio of (a).

Optionally, the second active metal M is Mo, W, Ti, Zr, or Nb.

Optionally, the content of the first active component is 0.01-10 wt%, the content of the second active component is 2-80 wt%, and the content of the carrier is 10-97 wt% calculated on the metal element and based on the dry weight of the catalyst;

preferably, the content of the first active component is 0.1-5 wt%, the content of the second active component is 5-50 wt%, and the content of the carrier is 45-94 wt% calculated on the metal element and based on the dry weight of the catalyst.

Optionally, the support is alumina, silica, titania, magnesia, zirconia, thoria, beryllia, clay, molecular sieves, or activated carbon, or a combination of two or three thereof.

In a second aspect of the present disclosure: there is provided a method for preparing a carbide-based catalyst, the method comprising the steps of:

a. loading a first active metal and a second active metal on a carrier through impregnation to obtain an impregnated material;

b. carbonizing the impregnated material obtained in the step a in a carbon-containing compound atmosphere to obtain a carbonized material;

c. b, oxidizing the carbonized material obtained in the step b in an oxygen-containing compound atmosphere;

wherein the first active metal is Ir or Rh; the second active metal is one selected from group IVB, group VB and group VIB metals.

Optionally, in the step a, the weight ratio of the first active metal and the second active metal calculated by metal elements to the carrier calculated by dry basis is (0.0001-1): (0.021-8): 1, preferably (0.0011 to 0.11): (0.053-1.1): 1;

the impregnation conditions include: the temperature is 10-90 ℃, and preferably 15-40 ℃; the time is 1-10 h, preferably 2-6 h.

Optionally, the method further comprises: drying and roasting the impregnated material obtained in the step a, and then performing the operation of the step b; the drying conditions are as follows: the temperature is 80-150 ℃, and the time is 1-24 h; the roasting conditions are as follows: the temperature is 200-700 ℃, and the time is 1-12 h.

Optionally, in step b, the carbon-containing compound is carbon monoxide, methane, ethane, ethylene, acetylene, propane, propylene or propyne, or a combination of two or three thereof; in the atmosphere containing the carbon compound, the content of the carbon compound is 5-50% by volume, preferably 10-25% by volume;

the carbonization conditions include: the temperature is 300-1000 ℃, preferably 500-900 ℃; the time is 1-24 h, preferably 2-12 h.

Optionally, the method further comprises: and c, cooling the carbonized material obtained in the step b to below 50 ℃ in the atmosphere of the carbon-containing compound or the hydrogen gas or the inert atmosphere, treating the material in the inert atmosphere for 0.2-24 h, and then performing the operation in the step c.

Optionally, in step c, the oxygenate is oxygen, carbon dioxide or water vapor, or a combination of two or three thereof; in the oxygen-containing compound atmosphere, the content of the oxygen-containing compound is 0.01-15% by volume, preferably 0.1-10% by volume;

the oxidation conditions include: the temperature is 100-800 ℃, and preferably 250-550 ℃; the time is 1-24 h, preferably 2-12 h.

Optionally, the second active metal is Mo, W, Ti, Zr, or Nb;

the carrier is alumina, silica, titanium oxide, magnesia, zirconia, thoria, beryllium oxide, clay, molecular sieve or activated carbon, or the combination of two or three of the above.

A third aspect of the disclosure: there is provided a carbide-based catalyst prepared by the method of the second aspect of the disclosure.

A fourth aspect of the present disclosure: there is provided a process for the hydrogenolysis ring opening of cycloalkanes comprising contacting a feed containing cycloalkanes, hydrogen and a catalyst under conditions to catalyse the hydrogenolysis ring opening of cycloalkanes wherein the catalyst is a carbide based catalyst as described in the first or third aspect of the disclosure.

Optionally, the conditions for catalytic hydrogenolysis ring opening of cycloalkanes comprise: the temperature is 180-450 ℃, preferably 220-400 ℃; the pressure is 1-18 MPa, preferably 2-12 MPa; the volume ratio of the hydrogen to the oil is 50-10000, preferably 50-5000; the mass space velocity is 0.1-100 h^-1Preferably 0.2 to 80 hours^-1。

Compared with the catalyst with the same active metal content prepared by the prior art, the carbide-based catalyst disclosed by the invention has excellent catalytic ring opening activity for hydrogenolysis of cycloalkane and high linear alkane selectivity.

Additional features and advantages of the disclosure will be set forth in the detailed description which follows.

Detailed Description

The following describes in detail specific embodiments of the present disclosure. It should be understood that the detailed description and specific examples, while indicating the present disclosure, are given by way of illustration and explanation only, not limitation.

The first aspect of the disclosure: a carbide-based catalyst is provided, which comprises a carrier, a first active component and a second active component, wherein the first active component is a first active metal Ir or Rh, and the second active component is a complex MC of a carbide and an oxide of a second active metal M_x-MO_yWherein M is one selected from metals of IVB group, VB group and VIB group, x is 0.5-1, and y is 1.5-3.

In the catalyst of the present disclosure, the presence of a specific complex MC of a carbide and an oxide of the second active metal M_x-MO_yAs a second active component, compared with the catalyst with the same metal content prepared by the prior art, the catalyst has obviously higher catalytic activity for catalyzing the hydrogenolysis ring opening of the naphthenic hydrocarbon and the selectivity of the straight-chain alkane.

According to the present disclosure, the catalyst satisfies (M)_MCx/M_MOy)_XPS0.1 to 20, wherein (M)_MCx/M_MOy)_XPSMC in terms of metal element M in the catalyst characterized by X-ray photoelectron spectroscopy_xAnd MO_yIn a weight ratio of (a). Preferably, (M)_MCx/M_MOy)_XPSThe catalyst in the range is 1-10, and has excellent catalytic hydrogenolysis ring opening performance.

The above X and y can be measured according to X-ray Photoelectron Spectroscopy (XPS) tests and their data handbook (Moulder, J.F.; Stickle, W.F.; Sobol, P.E.; Bomben, K.D. handbook of Photoelectron Spectroscopy; Chastain, J.E.; Perkin-Elmer:1992), X-ray powder diffraction (XRD) tests and corresponding reference samples. The content of the metal element in the catalyst is characterized by X-ray photoelectron spectroscopy, which is well known to those skilled in the art, the weight ratio can be obtained by converting the peak area of the corresponding element characteristic peak of the corresponding compound, and the X-ray photoelectron spectroscopy can be carried out by a conventional method by using a conventional measuring instrument, without special requirements in the present disclosure. For example, the above x and y and (M)_MCx/M_MOy)_XPSTesting method ofThe method specifically comprises XPS measuring instrument ESCALAB 250 type instrument manufactured by Thermo Scientific company, exciting source is monochromator Al K α X-ray with power of 150W, and basic vacuum during analysis is about 6.5 × 10^-8Pa, laser voltage of 50kV and laser current of 50mA, binding energy corrected by C1 s peak (284.8 eV). XRD test was carried out by Philips XPERT series instrument using Cu K α ray (λ 0.154nm), Ni filter, operating voltage of 40kV, operating current of 30mA, and sweep range of 5 to 75 ° (2 θ). The second active metal M was exemplified as tungsten (reference example 1), and XPS measured W4f_7/2Has two peaks of 35.7eV and 31.4eV, respectively, corresponding to WO₃And WC_x(ii) a Can be calculated according to the ratio of the two peak areas (M)_MCx/M_MOy)_XPSThe value is obtained. XRD shows that the peak positions are 31.5, 35.8, 48.4, 64.1-65.7 and 73.2 at 2 theta, and respectively correspond to characteristic signals of (001), (100), (101), (110) and (111) of the WC film of the standard reference sample. Combining the XPS and XRD test results, the second active component is WC-WO₃I.e., x is 1 and y is 3. According to the present disclosure, the second active metal M may be various conventional active metals that are easy to form carbides in the field of hydrogenation catalysis, and preferably, the second active metal M is Mo, W, Ti, Zr, or Nb.

According to the present disclosure, the first active component may be contained in an amount of 0.01 to 10 wt%, the second active component may be contained in an amount of 2 to 80 wt%, and the carrier may be contained in an amount of 10 to 97 wt%, based on the metal element and based on the dry weight of the catalyst. Preferably, the content of the first active component is 0.1-5 wt%, the content of the second active component is 5-50 wt%, and the content of the carrier is 45-94 wt%, calculated by metal elements and based on the dry weight of the catalyst, and the catalyst in the above range has higher catalytic activity for ring opening of naphthenic hydrocarbon hydrogenolysis.

According to the present disclosure, the support may be alumina, silica, titania, magnesia, zirconia, thoria, beryllia, clay, molecular sieves or activated carbon, or a combination of two or three of them. Preferably, the support is silica, alumina or silica-alumina. The carrier can also be obtained by modifying the substances by one or more of phosphorus, silicon, fluorine and boron, and can be obtained by commercial products or modification by the existing method.

In a second aspect of the present disclosure: there is provided a method for preparing a carbide-based catalyst, the method comprising the steps of:

a. loading a first active metal and a second active metal on a carrier through impregnation to obtain an impregnated material;

b. carbonizing the impregnated material obtained in the step a in a carbon-containing compound atmosphere to obtain a carbonized material;

c. b, oxidizing the carbonized material obtained in the step b in an oxygen-containing compound atmosphere;

wherein the first active metal is Ir or Rh; the second active metal is one selected from group IVB, group VB and group VIB metals.

Compared with the catalyst with the same metal content prepared by the prior art, the carbide-based catalyst disclosed by the invention has obviously higher catalytic ring opening activity for catalyzing the hydrogenolysis of cycloalkanes and linear alkane selectivity. The chemical state of the second active component of the catalyst is represented by X-ray photoelectron spectroscopy, and the existence of the carbide MC with lower binding energy in the characteristic electron binding energy interval of the second active metal M is found_xAnd higher binding energy oxide MO_yAccording to XPS test and data handbook thereof, XRD test and corresponding reference sample, x is 0.5-1, and y is 1.5-3; further, the catalyst satisfies (M)_MCx/M_MOy)_XPS0.1 to 20, preferably, (M)_MCx/M_MOy)_XPS1 to 10, wherein (M)_MCx/M_MOy)_XPSMC in terms of metal element M in the catalyst characterized by X-ray photoelectron spectroscopy_xAnd MO_yIn a weight ratio of (a).

According to the present disclosure, the "supporting the first active metal and the second active metal on the carrier by impregnation" in step a may be carried out by one or more of the following manners:

1) impregnating the carrier with a first impregnation liquid containing a first active metal precursor, and then impregnating the carrier with a second impregnation liquid containing a second active metal precursor;

2) impregnating the carrier with a second impregnation liquid containing a second active metal precursor, and then impregnating the carrier with a first impregnation liquid containing a first active metal precursor;

3) simultaneously impregnating the carrier with a first impregnation liquid containing a first active metal precursor and a second impregnation liquid containing a second active metal precursor;

4) the first active metal precursor and the second active metal precursor are prepared into an impregnation liquid, and then the carrier is impregnated by the impregnation liquid.

Wherein the first active metal precursor is a compound containing a first active metal, and the first active metal is Ir or Rh; the second active metal precursor is a compound containing a second active metal, and the second active metal is one selected from metals in IVB group, VB group and VIB group. Further, the first active metal is preferably Ir; the second active metal M is Mo, W, Ti, Zr or Nb. The first active metal precursor may be various soluble compounds of the first active metal, preferably a nitrate, acetate, sulfate, chloride or acid of the first active metal, or a combination of two or three thereof; for example, when the first active metal is Ir, the first metal precursor may be H₂IrCl₆、(NH₄)₂IrCl₆、IrCl₃Or (NH)₄)₃IrCl₆And the like. The second active metal precursor may be various soluble compounds of the second active metal, preferably a nitrate, acetate, sulfate, chloride or acid of the second active metal, or a combination of two or three thereof. The first impregnation liquid/the second impregnation liquid is a solution obtained by mixing a first metal precursor/a second metal precursor with a suitable solvent (the first active metal precursor and the second active metal precursor are prepared into one impregnation liquid, namely the first active metal precursor, the second active metal precursor and the suitable solvent are prepared into one impregnation liquidPreferably, a solvent is mixed to obtain an impregnation solution containing the first active metal precursor and the second active metal precursor), and the solvent may be water, ethanol, ethylene glycol, n-propanol, isopropanol, propylene glycol, n-hexane, cyclohexane or n-heptane, preferably water.

According to the present disclosure, the support may be alumina, silica, titania, magnesia, zirconia, thoria, beryllia, clay, molecular sieves or activated carbon, or a combination of two or three of them. Preferably, the support is silica, alumina or silica-alumina. The carrier can also be obtained by modifying the substances by one or more of phosphorus, silicon, fluorine and boron, and can be obtained by commercial products or modification by the existing method.

According to the disclosure, in step a, the weight ratio of the first active metal, the second active metal, and the carrier on a dry basis, calculated as the metal element, may be (0.0001 to 1): (0.021-8): 1. in order to further improve the catalytic naphthene hydrogenolysis activity of the catalyst, the weight ratio of the first active metal, the second active metal and the carrier on a dry basis is preferably (0.0011-0.11): (0.053-1.1): 1.

in step a, the impregnation method is not particularly limited, and various methods known to those skilled in the art, for example, an equal volume impregnation method, a supersaturation impregnation method, and the like, may be used according to the present disclosure. Specifically, the impregnation conditions may include: the impregnation conditions include: the temperature is 10-90 ℃, and preferably 15-40 ℃; the time is 1-10 h, preferably 2-6 h.

According to the present disclosure, to further improve the catalytic naphthene hydrogenolysis ring-opening activity and the linear paraffin selectivity of the catalyst, the method may further comprise: and c, drying and roasting the impregnated material obtained in the step a, and then performing the operation of the step b. Wherein, the drying conditions can be as follows: the temperature is 80-150 ℃, and the time is 1-24 h; the roasting conditions can be as follows: the temperature is 200-700 ℃, and the time is 1-12 h.

According to the present disclosure, in step b, the carbon-containing compound may be carbon monoxide, methane, ethane, ethylene, acetylene, propane, propylene or propyne, or a combination of two or three thereof. The purpose of the disclosure can be achieved when the content of the carbon-containing compound in the carbon-containing compound atmosphere is small, for example, the content of the carbon-containing compound in the carbon-containing compound atmosphere can be 5 to 50% by volume, preferably 10 to 25% by volume; in this case, the carbon compound-containing atmosphere may further include hydrogen, nitrogen, argon, or helium, or a combination of two or three thereof. The carbonization conditions may include: the temperature is 300-1000 ℃, preferably 500-900 ℃; the time is 1-24 h, preferably 2-12 h.

According to the present disclosure, in order to facilitate the performing of step c, the method may further include: and c, cooling the carbonized material obtained in the step b to below 50 ℃ in the atmosphere of the carbon-containing compound, the hydrogen gas or the inert atmosphere, treating the material in the inert atmosphere for 0.2-24 h, and then performing the operation in the step c. Wherein, the inert atmosphere can be nitrogen, argon or helium.

According to the present disclosure, in step c, the oxygenate is oxygen, carbon dioxide or water vapor, or a combination of two or three thereof. The purpose of the present disclosure can be achieved when the content of the oxygen-containing compound in the oxygen-containing compound atmosphere is small, for example, the content of the oxygen-containing compound in the oxygen-containing compound atmosphere may be 0.01 to 15 vol%, preferably 0.1 to 10 vol%; in this case, the oxygen-containing compound atmosphere may further include nitrogen, argon, or helium, or a combination of two or three thereof. The oxidation conditions may include: the temperature is 100-800 ℃, and preferably 250-550 ℃; the time is 1-24 h, preferably 2-12 h.

The carbide-based catalyst prepared by the method provided by the disclosure has the advantages that the first active metal is formed into the first active component, and the second active metal is formed into the second active component after carbonization and oxidation; the content of the first active component can be 0.01-10 wt%, the content of the second active component can be 2-80 wt%, and the content of the carrier can be 10-97 wt% calculated on the metal element and based on the dry weight of the catalyst. Preferably, the content of the first active component is 0.1-5 wt%, the content of the second active component is 5-50 wt%, and the content of the carrier is 45-94 wt% calculated on the metal element and based on the dry weight of the catalyst.

A third aspect of the disclosure: there is provided a carbide-based catalyst prepared by the method of the second aspect of the disclosure.

The catalyst provided by the disclosure has higher catalytic naphthene hydrogenolysis ring-opening activity and linear alkane selectivity when being used for naphthene hydrogenolysis ring-opening reaction. Accordingly, the fourth aspect of the present disclosure: there is provided a process for the hydrogenolysis ring opening of cycloalkanes comprising contacting a feed containing cycloalkanes, hydrogen and a catalyst under conditions to catalyse the hydrogenolysis ring opening of cycloalkanes wherein the catalyst is a carbide based catalyst as described in the first or third aspect of the disclosure.

The catalyst of the present disclosure can be used in hydrogenolysis ring-opening reactions of various feedstocks containing naphthenes, preferably feedstocks having an aromatics content of less than 15 wt% and a sulfur content of less than 30ppm, for example, the feedstocks containing naphthenes may be naphthene model compounds, or naphthene-containing gasoline, kerosene, or diesel fractions, or the like. The conditions for the catalytic hydrogenolysis ring opening of cycloalkanes may be performed with reference to the prior art, for example, the conditions for the hydrogenolysis ring opening of cycloalkanes may include: the temperature is 180-450 ℃, preferably 220-400 ℃; the pressure is 1-18 MPa, preferably 2-12 MPa; the volume ratio of the hydrogen to the oil is 50-10000, preferably 50-5000; the mass space velocity is 0.1-100 h^-1Preferably 0.2 to 80 hours^-1. The contacting may be carried out in any reactor sufficient to contact the cycloalkane-containing feedstock with the carbide-based catalyst to react under conditions that catalyze the hydrogenolysis opening of cycloalkanes, such as a fixed bed reactor, a slurry bed reactor, a moving bed reactor, or an ebullating bed reactor.

The following examples are presented to facilitate a better understanding of the present disclosure, but are not intended to limit the same.