Nickel-based bimetallic catalyst as well as preparation method and application thereof

Abstract

The invention provides a nickel-based bimetallic catalyst as well as a preparation method and application thereof. The preparation method comprises the following steps: (1) preparing a Ni-coated S-1-C precursor in situ; (2) mixing M metal salt and the Ni (at) S-1-C precursor, and sequentially grinding, melting and calcining to obtain a NiM (at) S-1 nickel-based bimetallic catalyst; wherein M is metal except nickel. According to the nickel-based bimetallic catalyst and the preparation method thereof, in-situ encapsulation and solid-phase melting calcination are combined, and the prepared nickel-based bimetallic catalyst shows excellent hydrogenolysis activity and aromatic hydrocarbon selectivity in catalysis of a lower mixed phenolic hydroxyl hydrogenolysis reaction and has a wide application prospect.

Description

Technical Field

[0001] The present invention relates to the technical field of catalysts, and in particular to a nickel-based bimetallic catalyst and a preparation method and application thereof. Background Art

[0002] Light aromatics benzene, toluene, xylene (referred to as "BTX") are important organic chemical raw materials used in the production of resins, rubbers, medicines, dyes and other products, mainly derived from petroleum. It is of great significance to prepare non-petroleum-based light aromatics from low-value phenolic substances such as phenol oil in low-temperature coal tar and biomass phenol oil through directional catalytic phenol hydroxyl hydrogenolysis.

[0003] However, due to the conjugation effect of the benzene ring, the CO bond in the phenolic hydroxyl group has a strong force, and the hydrogenation reaction system of phenols has an extremely complex reaction network with multiple parallel reactions and series reactions, which makes it very difficult to hydrogenolyze the hydroxyl group of phenols to produce aromatics.

[0004] In the existing reported patents and research papers, phenol or m-cresol is generally selected as a model substance for phenolic substances to carry out research, and the reported catalysts include precious metal-supported catalysts, non-precious metal-supported catalysts, sulfided catalysts, etc. Compared with precious metal catalysts, non-precious metal catalysts, especially nickel, have the potential for industrial application due to their higher hydrogenation activity, low price, and abundant reserves.

[0005] However, nickel-based supported catalysts have nickel (Ni) active centers mostly distributed on the outer surface of the support, uneven distribution of metal particles, and uneven particle size, which leads to the common problems of low phenolic hydroxyl hydrogenolysis activity and poor aromatic selectivity in nickel-based supported catalysts, and a lack of data reports on catalytic stability. In addition, existing NiM bimetallic catalysts still cannot balance catalytic activity and aromatic selectivity. Even under high temperature conditions, they still have problems such as low phenolic hydroxyl hydrogenolysis activity and low processing capacity.

[0006] Therefore, it is urgent to develop new, efficient and stable phenolic hydroxyl hydrogenolysis catalysts. Summary of the invention

[0007] In view of the deficiencies in the prior art, the purpose of the present invention is to provide a nickel-based bimetallic catalyst and a preparation method and use thereof, which solves the problems of low hydrogenolysis activity, high reaction temperature and small processing capacity of the existing nickel-based bimetallic catalyst.

[0008] To achieve this object, the present invention adopts the following technical solutions:

[0009] In a first aspect, the present invention provides a method for preparing a nickel-based bimetallic catalyst, the preparation method comprising the following steps: (1) preparing a Ni@S-1-C precursor in situ; (2) mixing an M metal salt and a Ni@S-1-C precursor, and sequentially grinding, melting and calcining the mixture to obtain a NiM@S-1 nickel-based bimetallic catalyst; wherein M is a metal other than nickel.

[0010] The present invention adopts Ni@S-1-C precursor and the second metal for melt calcination treatment. Compared with the impregnation method for preparing two bimetallic catalysts, the in-situ encapsulation is combined with melt calcination. In the early stage, Ni is first encapsulated in situ, and then a low-melting-point M metal salt is used for melt calcination preparation, thereby forming bimetallic nanoparticles and their interactions.

[0011] In the present invention, the Ni@S-1-C precursor is a precursor for preparing the Ni@S-1 catalyst but before reduction, and is recorded as the Ni@S-1-C precursor, wherein S-1 is pure silicon molecular sieve S-1, and is recorded as S-1-C to indicate that it is a precursor.

[0012] Preferably, the in-situ preparation of the Ni@S-1-C precursor in step (1) includes: mixing a silicon source, a template, a metal Ni precursor and water, performing a crystallization reaction, and the obtained crystallized product is sequentially subjected to solid-liquid separation, washing, drying and calcining to obtain a Ni@S-1-C precursor.

[0013] Preferably, the metallic Ni precursor comprises any one of nickel nitrate, nickel sulfate, nickel chloride or metallic nickel ions or a combination of at least two thereof, wherein typical but non-limiting combinations are a combination of nickel nitrate and nickel sulfate, a combination of nickel chloride and nickel sulfate, and a combination of nickel nitrate and nickel chloride.

[0014] Preferably, the silicon source comprises any one of tetraethyl orthosilicate, white carbon black, silica sol or solid silica gel, or a combination of at least two thereof, wherein typical but non-limiting combinations are a combination of tetraethyl orthosilicate and white carbon black, a combination of silica sol and white carbon black, a combination of tetraethyl orthosilicate and silica sol, and a combination of solid silica gel and white carbon black.

[0015] Preferably, the template includes any one of triethylamine, tributylamine, diisopropylamine, diisobutylamine, isobutylamine, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetramethylethyldiammonium or dimethyldiethylammonium hydroxide, or a combination of at least two thereof. Exemplary combinations include a combination of triethylamine and tributylamine, a combination of diisopropylamine and diisobutylamine, a combination of isobutylamine and tetraethylammonium hydroxide, or a combination of tetrapropylammonium hydroxide, tetramethylethyldiammonium and dimethyldiethylammonium hydroxide, etc.

[0016] Preferably, the temperature of the crystallization reaction in step (1) is 150-180°C, for example, it can be 150°C, 154°C, 157°C, 160°C, 164°C, 167°C, 170°C, 174°C, 177°C or 180°C, but is not limited to the listed values, and other values ​​not listed within the range are also applicable.

[0017] Preferably, the crystallization reaction time is 12 to 36 hours, for example, it can be 12 hours, 15 hours, 18 hours, 20 hours, 23 hours, 26 hours, 28 hours, 31 hours, 34 hours or 36 hours, but is not limited to the listed values, and other unlisted values ​​within the range are also applicable.

[0018] Preferably, the calcination temperature is 400-600°C, for example, it can be 400°C, 423°C, 445°C, 467°C, 489°C, 512°C, 534°C, 556°C, 578°C or 600°C, but is not limited to the listed values, and other unlisted values ​​within the range are also applicable.

[0019] Preferably, the calcination time is 2 to 10 h, for example, 2 h, 2.9 h, 3.8 h, 4.7 h, 5.6 h, 6.5 h, 7.4 h, 8.3 h, 9.2 h or 10 h, but is not limited to the listed values, and other values ​​not listed within the range are also applicable.

[0020] Preferably, the packaging amount of Ni in the Ni@S-1-C precursor is such that the Ni content in the NiM@S-1 nickel-based bimetallic catalyst is 1.0 to 5.0 wt%, for example, it can be 1.0 wt%, 1.5 wt%, 2.0 wt%, 3.0 wt%, 44.0 wt% or 5.0 wt%, etc., but is not limited to the listed values, and other unlisted values ​​within the range are also applicable.

[0021] The present invention preferably controls the packaging amount of Ni in the Ni@S-1-C precursor within a reasonable range. When the packaging amount of Ni content is low, there is a problem of low hydrogenolysis activity. When the packaging amount of Ni content is high, there are problems such as affecting the introduction of the second metal and the interaction therewith.

[0022] The present invention has no special requirements on the mass ratio of various substances such as silicon source, template agent and metal Ni precursor, and a suitable amount of Ni encapsulation can be obtained by using the mass ratio well known to those skilled in the art.

[0023] Preferably, the metal M in the M metal salt in step (2) comprises any one of Fe, Zn, Co, Mo, Mn, Cu, La, Ce, W, Bi, Sm or Ga, or a combination of at least two thereof, wherein typical but non-limiting combinations are a combination of Fe and Zn, a combination of Co and Zn, a combination of Fe and Co, a combination of Mn and Zn, a combination of Fe and Cu, a combination of La and Bi, a combination of La and Ga, and a combination of Ga and Zn.

[0024] Preferably, the anion in the M metal salt comprises nitrate.

[0025] Preferably, the encapsulation amount of M in the NiM@S-1 nickel-based bimetallic catalyst is 0.5 to 20 wt%, for example, it can be 0.5 wt%, 0.6 wt%, 1.0 wt%, 1.5 wt%, 2.0 wt%, 2.5 wt%, 3 wt%, 3.5 wt%, 4 wt%, 5 wt%, 7 wt%, 9 wt%, 10 wt%, 12 wt%, 14 wt%, 15 wt%, 17 wt%, 19 wt% or 20 wt%, etc., but is not limited to the listed values, and other values ​​not listed within the range are also applicable.

[0026] When the encapsulation amount of the preferred M of the present invention is too low, it is difficult to form good bimetallic nanoparticles with the metal Ni. When the encapsulation amount is too high, there are disadvantages such as covering the active sites of the metal Ni and causing pore blockage.

[0027] Preferably, the grinding time in step (2) is 4 to 8 h, for example, 4 h, 4.5 h, 4.9 h, 5.4 h, 5.8 h, 6.3 h, 6.7 h, 7.2 h, 7.6 h or 8 h, but is not limited to the listed values, and other values ​​not listed within the range are also applicable.

[0028] Preferably, the melting temperature is greater than or equal to the melting point of the M metal salt.

[0029] Preferably, the melting temperature is 0-15°C higher than the melting point of the M metal salt, for example, it may be 0°C, 1°C, 2°C, 4°C, 5°C, 7°C, 8°C, 10°C, 11°C, 12°C, 14°C or 15°C.

[0030] Preferably, the melting time is 4 to 15 h, for example, 4 h, 4.2 h, 4.3 h, 4.5 h, 4.8 h, 5.0 h, 5.2 h, 5.3 h, 5.4 h, 5.5 h, 5.6 h, 6.0 h, 8 h, 9 h, 10 h, 11 h, 12 h, 13 h, 14 h or 15 h, etc.

[0031] Preferably, the calcination temperature is 500-650°C, for example, it can be 500°C, 515°C, 535°C, 550°C, 565°C, 580°C, 600°C, 610°C, 630°C or 650°C, but is not limited to the listed values, and other unlisted values ​​within the range are also applicable.

[0032] Preferably, the calcination time is 4 to 6 hours, for example, 4 hours, 4.3 hours, 4.5 hours, 4.7 hours, 4.9 hours, 5.2 hours, 5.4 hours, 5.6 hours, 5.8 hours or 6 hours, but is not limited to the listed values, and other unlisted values ​​within the range are also applicable.

[0033] Preferably, the calcining atmosphere is any one of air, oxygen, nitrogen or argon, or a combination of at least two of them, wherein typical but non-limiting combinations are a combination of air and oxygen, a combination of nitrogen and oxygen, a combination of air and nitrogen, and a combination of argon and oxygen.

[0034] Preferably, the NiM@S-1 nickel-based bimetallic catalyst is reduced before use.

[0035] Preferably, the reduction temperature is 400-650°C, for example, it can be 400°C, 428°C, 456°C, 484°C, 512°C, 539°C, 567°C, 595°C, 623°C or 650°C, but is not limited to the listed values, and other unlisted values ​​within the range are also applicable.

[0036] Preferably, the reduction time is 4 to 10 h, for example, 4 h, 4.7 h, 5.4 h, 6 h, 6.7 h, 7.4 h, 8 h, 8.7 h, 9.4 h or 10 h, but is not limited to the listed values, and other unlisted values ​​within the range are also applicable.

[0037] Preferably, the reducing atmosphere is a hydrogen atmosphere.

[0038] In a second aspect, the present invention provides a nickel-based bimetallic catalyst, wherein the nickel-based bimetallic catalyst is prepared by the preparation method of the nickel-based bimetallic catalyst described in the first aspect.

[0039] Preferably, the catalyst is NiM@S-1, wherein the Ni content in the NiM@S-1 is 1.0-5.0wt%, for example, it can be 1.0wt%, 1.2wt%, 1.3wt%, 1.5wt%, 1.7wt%, 1.8wt%, 1.9wt%, 2.0wt%, 2.2wt%, 2.5wt%, 2.8wt%, 3.0wt%, 4.0wt% or 5.0wt%, etc.; the M content is 0.5-20wt%, for example, it can be 0.5wt%, 1wt%, 2wt%, 3wt%, 4wt%, 5wt%, 7wt%, 8wt%, 10wt%, 12wt%, 15wt%, 18wt% or 20wt%, etc.

[0040] Preferably, M comprises any one or a combination of at least two of Fe, Zn, Co, Mo, Mn, Cu, La, Ce, W, Bi, Sm or Ga, wherein typical but non-limiting combinations are a combination of Fe and Zn, a combination of Co and Zn, a combination of Fe and Co, a combination of Fe and Mn, a combination of Cu and Zn, a combination of Ce and Zn, a combination of Ce and Ga, and a combination of Ga and Sm.

[0041] The present invention preferably uses the above-mentioned metal M, which has the advantage of hydrogenation / dehydrogenation performance. Compared with metals such as Ti and V, it is easier for metal Ni to form good bimetallic active sites.

[0042] Preferably, the Ni and M form bimetallic nanoparticles.

[0043] Preferably, the particle size of the bimetallic nanoparticles is 2 to 6 nm, for example, it can be 2 nm, 2.5 nm, 2.9 nm, 3.4 nm, 3.8 nm, 4.3 nm, 4.7 nm, 5.2 nm, 5.6 nm or 6 nm, but is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0044] In a third aspect, the present invention provides a use of the nickel-based bimetallic catalyst described in the second aspect in the hydrogenolysis of phenolic hydroxyl groups to produce aromatic hydrocarbons.

[0045] Preferably, the use comprises: carrying out a hydrogenolysis reaction of phenolic hydroxyl-containing organic matter under the action of a nickel-based bimetallic catalyst.

[0046] Preferably, the phenolic hydroxyl-containing organic matter is any one of phenol, cresol, xylenol, guaiacol, eugenol, vanillin or diphenol, or a combination of at least two of them, wherein a typical but non-limiting combination is a combination of phenol and cresol, a combination of xylenol and cresol, a combination of phenol and xylenol, a combination of guaiacol and cresol, a combination of phenol and guaiacol, a combination of vanillin and cresol, a combination of diphenol and cresol, a combination of phenol and diphenol, a combination of eugenol and cresol. Specifically, the phenolic hydroxyl-containing organic matter includes phenol oil in low-temperature coal tar and / or biomass phenol oil.

[0047] Preferably, the temperature of the hydrogenolysis reaction is 250-350°C, for example, it can be 250°C, 262°C, 273°C, 284°C, 295°C, 306°C, 317°C, 328°C, 339°C or 350°C, but is not limited to the listed values, and other unlisted values ​​within the range are also applicable.

[0048] Preferably, the pressure of the hydrogenolysis reaction is 0.1-1.0 MPa, for example, 0.1 MPa, 0.2 MPa, 0.3 MPa, 0.4 MPa, 0.5 MPa, 0.6 MPa, 0.7 MPa, 0.8 MPa, 0.9 MPa or 1.0 MPa, but is not limited to the listed values, and other unlisted values ​​within the range are also applicable.

[0049] Preferably, the mass space velocity of the phenolic hydroxyl-containing organic matter in the hydrogenolysis reaction is 3 to 15 h -1 , for example, it can be 3h -1 、3.8h -1 , 4.6h - 1.5.4h -1 , 6.2h -1 , 6.9h -1 , 7.7h -1 , 8.5h -1 , 9.3h -1 , 10h -1 , 10.5h -1 , 11h -1 , 11.5h -1 , 12h -1 , 13h -1 , 14h -1 or 15h -1 The above values ​​are not limited to the above values, and other values ​​not listed in the above values ​​are also applicable.

[0050] The present invention has no particular limitation on the drying in the above process. Any drying device and method known to those skilled in the art can be used, and can also be adjusted according to the actual process, for example, it can be air drying, vacuum drying, oven drying or freeze drying, or a combination of different methods.

[0051] Compared with the prior art, the present invention has at least the following beneficial effects:

[0052] (1) The nickel-based bimetallic catalyst provided by the present invention has a relatively low nickel encapsulation amount (1.0-5.0 wt% Ni), and the prepared NiM bimetallic encapsulated catalyst still has a relatively high catalytic activity, thus saving the cost of the catalyst;

[0053] (2) The nickel-based bimetallic catalyst provided by the present invention still preferentially catalyzes the hydrogenolysis reaction of phenolic hydroxyl groups at a relatively low reaction temperature (≤300°C), thereby ensuring a high yield of aromatic hydrocarbons. Under preferred conditions, the conversion rate of m-cresol is above 83.3% and the toluene selectivity is above 81.0%. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 This is a TEM image of the NiCu@S-1 nickel-based bimetallic catalyst obtained in Example 1 of the present invention.

[0055] Figure 2 This is a TEM image of the NiCu@S-1 nickel-based bimetallic catalyst obtained in Example 2 of the present invention.

[0056] Figure 3 This is a TEM image of the NiMo@S-1 nickel-based bimetallic catalyst obtained in Example 4 of the present invention.

[0057] Figure 4 It is a TEM image of the Mo / Silicalite-1 catalyst obtained in Comparative Example 3 of the present invention.

[0058] Figure 5 This is a TEM image of the Ni@S-1 nickel-based catalyst obtained in Comparative Example 4 of the present invention. DETAILED DESCRIPTION

[0059] For the convenience of understanding the present invention, the present invention lists the following embodiments. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0060] Example 1

[0061] This embodiment provides a method for preparing a nickel-based bimetallic catalyst, the preparation method comprising the following steps:

[0062] (1) In situ preparation of Ni@S-1-C precursor; synthesizing Ni@Si-1 with Ni nanoparticles of 3 to 6 nm according to the method reported in Example 1 of ZL201910092758.5; the specific steps are as follows:

[0063] (a) Tetraethyl orthosilicate (TEOS), tetrapropylammonium hydroxide (TPAOH), nickel nitrate (Ni(NO3)2·6H2O), ethylenediamine (EDA) and deionized water were placed in a 500-mL beaker and stirred in a 70°C water bath for 5 h to obtain a gel. The molar ratio of SiO2, TPAOH and H2O in the obtained gel was 1:0.3:50.

[0064] (b) The gel was transferred to a hydrothermal crystallization reactor and crystallized at 170 °C for 48 h.

[0065] (c) After the temperature of the hydrothermal crystallization reactor drops to room temperature, the mixture is filtered, washed, dried, and transferred to a muffle furnace for calcination at 550°C for 10 h to obtain Ni@S-1-C prepared by the hydrothermal method.

[0066] (2) Copper nitrate trihydrate (Cu(NO3)2·3H2O) and Ni@S-1-C precursor were mixed and ground for 6 hours, respectively, and then transferred to an oven with an oven temperature slightly higher than the melting point of copper nitrate trihydrate (114.5°C) and set to 120°C for 15 hours. The mixture was calcined at 550°C in an air atmosphere for 6 hours to obtain a NiCu@S-1 nickel-based bimetallic catalyst with a content of 2.0 wt% Ni and 10.5 wt% Cu and a size of 2 to 6 nm.

[0067] Example 2

[0068] This embodiment provides a method for preparing a nickel-based bimetallic catalyst, the preparation method comprising the following steps:

[0069] (1) In situ preparation of Ni@S-1-C precursor; synthesizing Ni@S-1 with Ni nanoparticles of 3 to 5 nm according to the method reported in Example 1 of ZL201910092758.5; the specific steps are as follows:

[0070] (a) Tetraethyl orthosilicate (TEOS), tetrapropylammonium hydroxide (TPAOH), nickel nitrate (Ni(NO3)2·6H2O), ethylenediamine (EDA) and deionized water were placed in a 500-mL beaker and stirred in a 70°C water bath for 2 h to obtain a gel. The molar ratio of SiO2, TPAOH and H2O in the obtained gel was 1:0.5:60.

[0071] (b) The gel was transferred to a hydrothermal crystallization reactor and crystallized at 180 °C for 24 h.

[0072] (c) After the temperature of the hydrothermal crystallization reactor drops to room temperature, the product is filtered, washed, dried, and transferred to a muffle furnace for calcination at 600°C for 2 h to obtain Ni@S-1-C prepared by the hydrothermal method.

[0073] (2) Copper nitrate trihydrate (Cu(NO3)2·3H2O) and Ni@S-1-C precursor were mixed and ground for 4 h, respectively, and then transferred to an oven with an oven temperature slightly higher than the melting point of copper nitrate trihydrate (114.5°C) and set to 120°C for 6 h. The mixture was calcined at 500°C in an air atmosphere for 4 h to obtain a NiCu@S-1 nickel-based bimetallic catalyst with a size of 1.5 wt% Ni and 6.4 wt% Cu and a particle size of 2 to 5 nm.

[0074] Example 3

[0075] This embodiment provides a method for preparing a nickel-based bimetallic catalyst, the preparation method comprising the following steps:

[0076] (1) In situ preparation of Ni@S-1-C precursor; synthesizing Ni@Si-1 with Ni nanoparticles of 3 to 6 nm according to the method reported in Example 1 of ZL201910092758.5; the specific steps are as follows:

[0077] (a) Tetraethyl orthosilicate (TEOS), tetrapropylammonium hydroxide (TPAOH), nickel nitrate (Ni(NO3)2·6H2O), ethylenediamine (EDA) and deionized water were placed in a 500-mL beaker and stirred in a 78°C water bath for 6 h to obtain a gel. The molar ratio of SiO2, TPAOH and H2O in the obtained gel was 1:0.3:40.

[0078] (b) The gel was transferred to a hydrothermal crystallization reactor and crystallized at 150 °C for 72 h.

[0079] (c) After the temperature of the hydrothermal crystallization reactor drops to room temperature, the mixture is filtered, washed, dried, and transferred to a muffle furnace for calcination at 450°C for 10 h to obtain Ni@S-1-C prepared by the hydrothermal method.

[0080] (2) Cobalt nitrate hexahydrate (Co(NO3)2·6H2O) and Ni@S-1-C precursor were mixed and ground for 8 h, respectively, and then transferred to an oven with an oven temperature slightly higher than the melting point of cobalt nitrate hexahydrate (105 °C) and set to 110 °C for 6 h. The oven was calcined at 650 °C for 4 h in a nitrogen atmosphere to obtain a NiCo@S-1 nickel-based bimetallic catalyst with a content of 1.5 wt% Ni and 4.4 wt% Co and a size of 2 to 3 nm.

[0081] Example 4

[0082] This embodiment provides a method for preparing a nickel-based bimetallic catalyst, the preparation method comprising the following steps:

[0083] (1) In situ preparation of Ni@S-1-C precursor; synthesizing Ni@Si-1 nanoparticles with a size of 4 to 7 nm according to the method reported in ZL201910092758.5; the specific steps are as follows:

[0084] (a) Silica sol, tetrapropylammonium hydroxide (TPAOH), nickel nitrate (Ni(NO3)2·6H2O), ethylenediamine (EDA) and deionized water were placed in a 500-mL beaker and stirred in a 75°C water bath for 5 h to obtain a gel. The molar ratio of SiO2, TPAOH and H2O in the obtained gel was 1:0.3:45.

[0085] (b) The gel was transferred to a hydrothermal crystallization reactor and crystallized at 155 °C for 40 h.

[0086] (c) After the temperature of the hydrothermal crystallization reactor drops to room temperature, the mixture is filtered, washed, dried, and transferred to a muffle furnace for calcination at 450°C for 8 h to obtain Ni@S-1-C prepared by the hydrothermal method.

[0087] (2) Ammonium molybdate and Ni@S-1-C precursor were mixed and ground for 7 hours, respectively, and then transferred to an oven with an oven temperature slightly higher than the melting point of ammonium molybdate (105°C) and set to 130°C for 8 hours. The mixture was melt-calcined at 600°C in a nitrogen atmosphere for 5 hours to obtain a NiMo@S-1 nickel-based bimetallic catalyst with a size of 2 to 4 nm and a content of 2.0 wt% Ni and 9.6 wt% Mo.

[0088] Example 5

[0089] This embodiment provides a method for preparing a nickel-based bimetallic catalyst, the preparation method comprising the following steps:

[0090] (1) In situ preparation of Ni@S-1-C precursor; synthesizing Ni@Si-1 nanoparticles with a size of 4 to 7 nm according to the method reported in ZL201910092758.5; the specific steps are as follows:

[0091] (a) Silica sol, tetrapropylammonium hydroxide (TPAOH), nickel nitrate (Ni(NO3)2·6H2O), ethylenediamine (EDA) and deionized water were placed in a 500-mL beaker and stirred in a 70°C water bath for 5 h to obtain a gel. The molar ratio of SiO2, TPAOH and H2O in the obtained gel was 1:0.3:50.

[0092] (b) The gel was transferred to a hydrothermal crystallization reactor and crystallized at 170 °C for 45 h.

[0093] (c) After the temperature of the hydrothermal crystallization reactor drops to room temperature, the mixture is filtered, washed, dried, and transferred to a muffle furnace for calcination at 550°C for 8 h to obtain Ni@S-1-C prepared by the hydrothermal method.

[0094] (2) Cerium nitrate hexahydrate and Ni@S-1-C precursor were mixed and ground for 4 h, respectively, and then transferred to an oven with a temperature slightly higher than the melting point of cerium nitrate hexahydrate (96 °C) and set to 100 °C for 6 h. The mixture was melt-calcined at 550 °C in an air atmosphere for 6 h to obtain a NiCe@S-1 nickel-based bimetallic catalyst with 2.0 wt% Ni and 2.2 wt% Ce and a size of 2 to 3 nm.

[0095] Example 6

[0096] This embodiment provides a method for preparing a nickel-based bimetallic catalyst. The preparation method is the same as that of Example 1 except that the Ni content in the nickel-based bimetallic catalyst is 6 wt %, and will not be described in detail here.

[0097] Example 7

[0098] This embodiment provides a method for preparing a nickel-based bimetallic catalyst. The preparation method is the same as that of Example 1 except that the Ni content in the nickel-based bimetallic catalyst is 0.1 wt %, and will not be described in detail herein.

[0099] Example 8

[0100] This embodiment provides a method for preparing a nickel-based bimetallic catalyst. The preparation method is the same as that of Example 1, except that the Cu content in the NiCu@S-1 nickel-based bimetallic catalyst is 0.1 wt %, and will not be described in detail here.

[0101] Example 9

[0102] This embodiment provides a method for preparing a nickel-based bimetallic catalyst. The preparation method is the same as that of Example 1, except that the Cu content in the NiCu@S-1 nickel-based bimetallic catalyst is 25 wt %, and will not be described in detail here.

[0103] Example 10

[0104] This embodiment provides a method for preparing a nickel-based bimetallic catalyst. The preparation method is the same as that of Example 1, except that Cu in the NiCu@S-1 nickel-based bimetallic catalyst is replaced by Ti and the corresponding precursor is replaced by titanium tetrachloride, and will not be repeated here.

[0105] Comparative Example 1

[0106] This comparative example provides a method for preparing a nickel-based bimetallic catalyst. The preparation method is the same as Example 1, except that the Ni@S-1-C precursor is replaced by a Ni@ZSM-5 precursor (for the specific preparation method, see Example 1 in CN111250152B, and the packaging amount is the same as that in Example 1), and will not be repeated here.

[0107] Comparative Example 2

[0108] This comparative example provides a method for preparing a Cu / S-1 catalyst, the preparation method comprising:

[0109] (a) 26.0 g of tetraethyl orthosilicate (TEOS), 10.1 g of tetrapropylammonium hydroxide (TPAOH) and 56.0 g of deionized water were placed in a 500 mL beaker and stirred in a 70° C. water bath for 6 h; then transferred to a hydrothermal kettle and crystallized at 170° C. for 12 h; after cooling, the mixture was taken out for filtration, washed and dried, and then transferred to a 550° C. muffle furnace for calcination for 8 h to obtain S-1 molecular sieve for use;

[0110] (b) The calcined S-1 molecular sieve and copper nitrate (Cu(NO3)2·3H2O) were placed in a mortar and ground for 2 h; the ground mixture was then transferred to a muffle furnace at 550°C and calcined for 6 h to obtain a calcined Cu / S-1 catalyst.

[0111] Comparative Example 3

[0112] This comparative example provides a method for preparing a Mo / Silicalite-1 catalyst, the preparation method comprising:

[0113] (a) S-1 molecular sieve synthesis was prepared according to the method described in Comparative Example 2;

[0114] (b) The calcined S-1 molecular sieve and molybdenum oxide (MoO3) were mixed and ground for 4 hours; then transferred to a muffle furnace at 600°C and calcined for 8 hours to obtain a Mo / S-1 catalyst.

[0115] Comparative Example 4

[0116] This comparative example provides a method for preparing a nickel-based bimetallic catalyst. The preparation method is the same as Example 1 except that step (2) is not performed, and the details are not repeated here.

[0117] Comparative Example 5

[0118] This comparative example provides a method for preparing a nickel-based bimetallic catalyst. The preparation method is the same as Example 1 except that step (2) is replaced by impregnation of a second metal, and the rest is not repeated here.

[0119] Specifically, the Ni@S-1 precursor was impregnated with a 1 mol / L copper nitrate trihydrate (Cu(NO3)2·3H2O) solution for 4 h, and then melt-calcined at 550°C in an air atmosphere for 6 h to obtain a 3-30 nm NiCu@S-1 nickel-based bimetallic catalyst.

[0120] Comparative Example 6

[0121] This comparative example provides a method for preparing a nickel-based bimetallic catalyst. The preparation method is the same as Example 1 except that Cu is encapsulated in situ in step (1) and nickel nitrate is added in step (2), and the rest is not repeated here.

[0122] Figure 1 is a TEM image of the NiCu@S-1 nickel-based bimetallic catalyst obtained in Example 1; Figure 2 This is the TEM image of the NiCu@S-1 nickel-based bimetallic catalyst obtained in Example 2. Figure 3 This is the TEM image of the NiMo@S-1 nickel-based bimetallic catalyst obtained in Example 4. Figure 4 This is the TEM image of the Mo / Silicalite-1 catalyst obtained in Comparative Example 3. Figure 5 This is a TEM image of the Ni@S-1 nickel-based catalyst obtained in Comparative Example 4. Figure 1 to Figure 5 It can be seen that the method for preparing the nickel-based bimetallic catalyst provided by the present invention can effectively control the particle size and uniform distribution of the nanoparticles of the NiM bimetallic.

[0123] Application Example 1

[0124] This application example provides a meta-cresol hydrodeoxygenation reaction, and the meta-cresol hydrodeoxygenation reaction includes the following steps:

[0125] The catalyst prepared in Example 1 with a size of 20-40 mesh is placed in the middle of a fixed bed reaction tube, and the upper and lower sections of the reaction tube are filled with quartz sand, and m-cresol is used as a raw material;

[0126] Before feeding, the catalyst prepared in Example 1 was reduced online (using hydrogen atmosphere) at a reduction temperature of 500° C. for 10 h; then the reaction temperature was lowered to 300° C., the reaction pressure was set to 0.25 MPa, and the mass space velocity of m-cresol was 6 h -1 , start the feeding reaction.

[0127] Application Example 2

[0128] This application example provides a meta-cresol hydrodeoxygenation reaction, and the meta-cresol hydrodeoxygenation reaction includes the following steps:

[0129] The catalyst prepared in Example 2 with a size of 20-40 mesh is placed in the middle of a fixed bed reaction tube, and the upper and lower sections of the reaction tube are filled with quartz sand, and m-cresol is used as a raw material;

[0130] Before feeding, the catalyst prepared in Example 2 was reduced online (using hydrogen atmosphere) at a reduction temperature of 650°C for 4 hours; then the reaction temperature was lowered to 250°C, the reaction pressure was set to 0.5 MPa, and the mass space velocity of m-cresol was 3 h -1 , start the feeding reaction.

[0131] Application Example 3

[0132] This application example provides a meta-cresol hydrodeoxygenation reaction, and the meta-cresol hydrodeoxygenation reaction includes the following steps:

[0133] The catalyst prepared in Example 3 with a size of 20-40 mesh is placed in the middle of a fixed bed reaction tube, and the upper and lower sections of the reaction tube are filled with quartz sand, and m-cresol is used as a raw material;

[0134] Before feeding, the catalyst prepared in Example 3 was reduced online (using hydrogen atmosphere) at a reduction temperature of 400°C for 10 h; then the reaction temperature was lowered to 350°C, the reaction pressure was set to 0.1 MPa, and the mass space velocity of m-cresol was set to 10 h. -1 , start the feeding reaction.

[0135] Application Example 4

[0136] This application example provides a meta-cresol hydrodeoxygenation reaction. The meta-cresol hydrodeoxygenation reaction uses the catalyst in Example 4, and the specific reaction conditions are the same as those in Application Example 1.

[0137] Application Example 5

[0138] This application example provides a meta-cresol hydrodeoxygenation reaction, and the meta-cresol hydrodeoxygenation reaction includes the following steps:

[0139] The catalyst prepared in Example 5 with a size of 20-40 mesh was placed in the middle of a fixed bed reaction tube, and the upper and lower sections of the reaction tube were filled with quartz sand, with m-cresol as the raw material;

[0140] Before feeding, the catalyst prepared in Example 5 was reduced online (using hydrogen atmosphere) at a reduction temperature of 420°C for 10 h; then the reaction temperature was lowered to 350°C, the reaction pressure was set to 0.2 MPa, and the mass space velocity of m-cresol was 3 h -1 , start the feeding reaction.

[0141] Application Examples 6 to 10 and Application Comparative Examples 1 to 6

[0142] Application Examples 6 to 10 and Application Comparative Examples 1 to 6 provide a meta-cresol hydrodeoxygenation reaction. The meta-cresol hydrodeoxygenation reaction is the same as Application Example 1 except that the catalysts in Examples 6 to 11 and Comparative Examples 1 to 6 are used respectively, and will not be described in detail herein.

[0143] The conversion rate and selectivity in the above application examples and application comparison examples were calculated, and the test results of the above application examples and application comparison examples are shown in Table 1.

[0144] Table 1

[0145]

[0146]

[0147] “ / ” in Table 1 indicates that there is no relevant data.

[0148] From Table 1, we can see the following points:

[0149] (1) It can be seen from Application Examples 1 to 5 that the nickel-based bimetallic catalyst prepared by the preparation method of the nickel-based bimetallic catalyst provided by the present invention can make the particle size of the NiM bimetallic in the range of 2 to 6 nm. The catalyst has excellent conversion rate and toluene selectivity in the hydrogenolysis reaction of phenolic hydroxyl organic matter based on low nickel content, wherein the conversion rate of m-cresol is above 83.3%, and the toluene selectivity is above 81.0%;

[0150] (2) By comparing Application Example 1 and Application Examples 6 to 7, it can be seen that in Application Example 6, the nickel encapsulation amount is high, resulting in a limited amount of the second metal introduced, a significant catalyst pore blocking effect, and ultimately affecting the phenol oil hydrogenolysis performance; in Application Example 7, nickel is used as the first metal, and the encapsulation amount is low, resulting in low phenol oil hydrogenolysis performance. Under the condition of 0.1wt% encapsulation amount, the prepared catalyst has basically no hydrogenolysis activity, which shows that the present invention preferably controls the nickel encapsulation amount within a reasonable range in order to have excellent hydrogenolysis performance;

[0151] By comparing Application Example 1 with Application Examples 8 to 9, it can be seen that the Cu content in Application Example 8 is low and there is basically no hydrogenolysis activity, while the metal Cu in Application Example 9 is far in excess and covers the original Ni active sites, resulting in low activity of the obtained catalyst in the phenol oil hydrogenolysis reaction. This shows that the present invention preferably controls the packaging amount of the second metal M and the packaging amount of nickel within a reasonable range at the same time, so as to further improve the conversion rate and toluene selectivity of the hydrogenolysis reaction of phenolic hydroxyl-containing organic matter.

[0152] (3) By comparing Application Example 1 and Application Example 8, it can be seen that the second metal M in Application Example 8 is Ti. Metal Ti is easily inserted into the S-1 molecular sieve framework, but it is difficult to form a bimetallic nano-active site with Ni, which ultimately leads to low activity of the catalyst in the phenol oil hydrogenolysis reaction. This shows that the present invention selects a specific metal M and a metal nickel compound to further improve the catalytic activity and toluene selectivity of the phenol oil hydrogenolysis reaction.

[0153] (4) In Comparative Example 1, ZSM-5 is selected as the molecular sieve, but since ZSM-5 has acidic sites, it inhibits the hydrogenolysis reaction of phenol oil and has poor catalytic performance; in Comparative Example 2, the Cu / S-1 catalyst and the Mo / S-1 catalyst prepared in Comparative Example 3 have almost no catalytic effect on m-cresol; in Comparative Example 4, step (2) is not performed, and in Comparative Example 5, an impregnation method is used, and the particle size of the bimetallic particles in the final catalyst is relatively large, and the catalytic effect is relatively poor; in Comparative Example 6, a Cu@S-1-C precursor is first prepared, and then Ni metal is added by melt calcination, resulting in a larger size of the nickel-copper bimetallic particles, and the catalytic performance is significantly reduced compared with that of Application Example 1. This shows that the preparation method of the catalyst provided by the present invention can more effectively ensure the particle size of the nickel-M bimetallic in the catalyst, and ultimately improve the catalytic activity and toluene selectivity.

[0154] Compared with single metal Ni, the NiM bimetallic catalyst provided by the present invention has higher aromatics selectivity and catalytic activity in the hydrogenolysis reaction of m-cresol. On the basis of Ni@S-1-C, the second metal is encapsulated to form the NiM@S-1 bimetallic encapsulated catalyst, which significantly improves the phenol conversion rate and aromatics selectivity. Compared with a single second metal, the effect is more prominent.

[0155] The present invention illustrates the detailed features of the present invention through the above embodiments, but the present invention is not limited to the above detailed features, that is, it does not mean that the present invention must rely on the above detailed features to be implemented. Those skilled in the art should understand that any improvement to the present invention, equivalent replacement of the technical features selected by the present invention, addition of auxiliary technical features, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A method for preparing a nickel-based bimetallic catalyst, characterized in that: The preparation method comprises the following steps: (1) In situ preparation of Ni@S-1-C precursor; (2) mixing the M metal salt and the Ni@S-1-C precursor, and sequentially grinding, melting and calcining to obtain the NiM@S-1 nickel-based bimetallic catalyst; Wherein, M is a metal other than nickel.

2. The preparation method according to claim 1, characterized in that: The in-situ preparation of the Ni@S-1-C precursor in step (1) comprises: A silicon source, a template, a metal Ni precursor and water are mixed to carry out a crystallization reaction, and the obtained crystallized product is sequentially subjected to solid-liquid separation, washing, drying and calcination to obtain a Ni@S-1-C precursor.

3. The preparation method according to claim 1 or 2, characterized in that: The packaging amount of Ni in the Ni@S-1-C precursor in step (1) is such that the Ni content in the NiM@S-1 nickel-based bimetallic catalyst is 1.0 to 5.0 wt%.

4. The preparation method according to any one of claims 1 to 3, characterized in that: The metal M in the M metal salt in step (2) includes any one of Fe, Zn, Co, Mo, Mn, Cu, La, Ce, W, Bi, Sm or Ga, or a combination of at least two thereof; Preferably, the anion in the M metal salt comprises nitrate; Preferably, the encapsulation amount of M in the NiM@S-1 nickel-based bimetallic catalyst is 0.5-20 wt%.

5. The preparation method according to any one of claims 1 to 4, characterized in that: The grinding time in step (2) is 4 to 8 hours; Preferably, the melting temperature is greater than or equal to the melting point of the M metal salt; Preferably, the melting temperature is 0 to 15° C. greater than the melting point of the M metal salt; Preferably, the calcination temperature is 500-650°C; Preferably, the calcination time is 4 to 6 hours; Preferably, the calcination atmosphere is any one of air, oxygen, nitrogen or argon, or a combination of at least two of them.

6. The preparation method according to any one of claims 1 to 5, characterized in that: The NiM@S-1 nickel-based bimetallic catalyst is first reduced before use; Preferably, the reduction temperature is 400-650°C; Preferably, the reduction time is 4 to 10 hours; Preferably, the reducing atmosphere is a hydrogen atmosphere.

7. A nickel-based bimetallic catalyst, characterized in that: The nickel-based bimetallic catalyst is prepared by the preparation method of the nickel-based bimetallic catalyst according to any one of claims 1 to 6.

8. The nickel-based bimetallic catalyst according to claim 7, characterized in that: The catalyst is NiM@S-1, wherein the Ni content in the NiM@S-1 is 1.0-5.0 wt%, and the M content is 0.5-20 wt%; Preferably, M includes any one or a combination of at least two of Fe, Zn, Co, Mo, Mn, Cu, La, Ce, W, Bi, Sm or Ga; Preferably, the Ni and M form bimetallic nanoparticles; Preferably, the particle size of the bimetallic nanoparticles is in the range of 2 to 6 nm.

9. Use of the nickel-based bimetallic catalyst according to claim 7 or 8 in the hydrogenolysis of phenolic hydroxyl groups to produce aromatic hydrocarbons.

10. The use according to claim 9, characterized in that The use includes: carrying out hydrogenolysis reaction of phenolic hydroxyl-containing organic matter under the action of nickel-based bimetallic catalyst; Preferably, the temperature of the hydrogenolysis reaction is 250-350°C; Preferably, the pressure of the hydrogenolysis reaction is 0.1 to 1.0 MPa; Preferably, the mass space velocity of the phenolic hydroxyl-containing organic matter in the hydrogenolysis reaction is 3 to 15 h -1 .

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