WO2016078261A1

WO2016078261A1 - Supported high dispersion nickel-based alloy catalyst preparation method and catalytic application thereof

Info

Publication number: WO2016078261A1
Application number: PCT/CN2015/074238
Authority: WO
Inventors: 张法智; 项建峰; 闻鑫; 杨志祥
Original assignee: 北京化工大学
Priority date: 2014-11-20
Filing date: 2015-03-13
Publication date: 2016-05-26
Also published as: CN104368345A

Abstract

Disclosed are a supported high dispersion nickel-based alloy catalyst preparation method and catalytic application thereof. In the present invention, Ni, M (M=Co, Zn, Cu, Fe and Cr and the like) metals in an LDH-like form are supported on a surface of a micro-spherical γ-Al₂O₃ carrier or within channels thereof via an in-situ growth method, the micro-sphericalγ-Al₂O₃ carrier having a particle diameter of 20-40 meshes; lamellar precursor LDHs containing Ni and M metal ions are grown in an outer portion and inner portion of the Al₂O₃ particles to form a supported high dispersion distribution, and roasted at a high temperature to be converted to the corresponding composite metal oxide after drying; and after reduction, the supported high dispersion nickel-based alloy catalyst having NiM distributed on the outer surface of the carrier particles or within the channels thereof. The supported high dispersion nickel-based alloy catalyst effectively improves conversion, selectivity and stability of the catalyst when applied to a selective hydrogenation reaction for cracking gasoline, and can also be used in the reactions of reforming methane and catalyzing hydrogenation of CO and CO₂ for preparing a light hydrocarbon and alcohol.

Description

Preparation method of supported high-dispersion nickel-based alloy catalyst and catalytic application thereof

Technical field

The invention belongs to the technical field of catalyst preparation, and particularly relates to a supported high-dispersion nickel-based alloy catalyst prepared by using in-situ growth method as an alumina and its application in the selective hydrogenation of pyrolysis gasoline.

Background technique

Pyrolysis gasoline is a valuable by-product of industrial pyrolysis of high temperature naphtha to ethylene and propylene, accounting for 50% to 80% of ethylene production. Its C ₅ ⁺ to C ₁₂ ⁺ hydrocarbons are the main components, including A large number of aromatic hydrocarbons (40-80%, benzene, toluene, xylene), diolefins, olefins and alkanes, so pyrolysis gasoline is often used as a high-octane gasoline blending oil or a raw material for triphenyl extraction. However, its stability is poor, and it is required to selectively hydrogenate styrene and diene which are easy to form colloid and carbon deposits at a lower temperature by using a supported metal catalyst to form corresponding ethylbenzene and monoolefin. Currently, the commonly used catalyst is a nickel-based or palladium-based catalyst supported on alumina. Compared with palladium-based catalysts, nickel-based catalysts have attracted much attention due to their low cost, good anti-toxic and anti-gel properties, and suitable hydrogenation/hydrogenolysis properties for hydrocarbons. In the selective hydrogenation of pyrolysis gasoline, the catalytic performance of the nickel-based catalyst is usually improved by adding additives, modifying the catalyst carrier, and introducing a new pre-vulcanization process. Among these methods, supported bimetallic catalysts have been shown to be effective in improving catalytic performance relative to single metal catalysts. Bimetallic catalysts exhibit excellent physical and chemical properties in combination with confinement effects and alloying effects. In particular, bimetallic catalysts can readily modulate their catalytic properties by adjusting the composition of the components and the arrangement of the atoms.

LDHs are compounds formed by the orderly assembly of interlayer anions and positively charged layers. The chemical composition is generally as follows: [M ²⁺ _1-x M ³⁺ _x (OH) ₂ ] ^x+ [A ^n- ] _x/n · yH ₂ O, wherein M ²⁺ and M ³⁺ are divalent and trivalent metal cations, respectively, on the host layer; An- is an interlayer anion; x is M ³⁺ /(M ²⁺ + The molar ratio of M ³⁺ ); y is the number of water molecules in the interlayer. The LDHs have the characteristics of tunable denaturation of the metal ion composition of the main layer, the charge density of the main layer and its variability, the variability of the type and amount of intercalated anion, the variability of the intra-layer space, and the variability of the interaction between the host and the guest. Such structural features make LDHs a meaningful platform for the development of new catalysts, catalyst precursors and catalyst supports with variable structure and properties.

Summary of the invention

SUMMARY OF THE INVENTION It is an object of the present invention to provide a process for the simple preparation of a supported high dispersion nickel-based alloy catalyst and the use of the catalyst for the selective hydrogenation of pyrolysis gasoline.

The invention supports Ni, M (M=Co, Zn, Cu, Fe, Cr, etc.) metals in the form of hydrotalcite by in situ growth method on a microspherical γ-Al ₂ O ₃ carrier having a particle size of 20-40 mesh. In the surface and its pores, a layered precursor LDHs containing Ni and M metal ions is grown outside and inside the Al ₂ O ₃ particles to form a supported high-dispersion distribution, which is dried and calcined at a high temperature to be converted into a corresponding composite metal oxide. After the reduction, the supported high-dispersion nickel-based alloy catalyst with NiM distributed on the outer surface of the carrier particles and the pores is obtained, which is applied to the selective hydrogenation reaction of pyrolysis gasoline, which can effectively improve the conversion rate, selectivity and stability of the catalyst. It can also be used for the reaction of methane reforming and catalyzing the hydrogenation of CO and CO _{2 to} prepare lower hydrocarbons and alcohols.

The supported high-dispersion nickel-base alloy catalyst of the invention has the following structure: the alloy NiM is distributed on the outer surface of the γ-Al ₂ O ₃ carrier particles and the pores thereof to form a distributed high-dispersion alloy distribution; the alloy NiM particle size At 1-8 nm, the γ-Al ₂ O ₃ carrier has a particle size of 20-40 mesh; the total loading of the alloy NiM is 6-12 wt% based on the total mass of the catalyst; M is Co, Zn, Cu, Fe or Cr.

The specific preparation method of the supported high-dispersion nickel-based alloy catalyst according to the present invention is as follows:

A. 3-5g γ-Al ₂ O ₃ particles with a particle size of 20-40 mesh, soluble nickel salt, soluble M salt, urea, quickly added to 10ml deionized water, vacuum impregnation for 1-3h and transferred to the autoclave Crystallizing at a temperature of 90-130 ° C for 12-24 h, filtering, washing the particles with deionized water to obtain a supported high-dispersion NiMAl-LDHs/Al ₂ O ₃ precursor;

B. The NiMAl-LDHs/Al ₂ O ₃ precursor is dried at 60-100 ° C for 6-12 h, then calcined at 400-600 ° C for 2-8 h to obtain LP-NiMO/Al ₂ O ₃ ;

C. The LP-NiMO/Al ₂ O ₃ prepared in step B is packed in a micro fixed bed reactor, heat treated at 400-600 ° C for 0.5-2 h under N ₂ protection, and the heating rate is 5-10 ° C / min; The reduction is carried out by using a mixture of H _{2 having a} flow rate of 30-80 mL/min and N ₂ having a flow rate of 10-30 mL/min, a reduction temperature of 400-600 ° C, a reduction time of 2-5 h, and a reduction pressure of 0.5-1 MPa. Upon completion, a supported high dispersion nickel-based alloy catalyst is obtained.

The molar ratio of urea to metal ion in the step A is (2:1)-(4:1).

The soluble nickel salt is nickel nitrate, nickel chloride or nickel sulfate.

The soluble M salt is nitric acid M, chlorinated M or sulfuric acid M.

The supported high-dispersion nickel-based alloy catalyst prepared by the above method is applied to a selective hydrogenation reaction of catalytic pyrolysis gasoline, the process conditions are: the reaction temperature is 40-60 ° C, and the volume ratio of hydrogen to pyrolysis gasoline is 50-100. , mass airspeed WHSV=10-30h ^-1 , catalyst dosage is 1.0-1.5g, total reaction pressure is 2.0-3.5MPa, hydrogen partial pressure is 0.4-3.0MPa, reaction time is 12-120h.

The invention adopts a supported high-dispersion nickel-based alloy catalyst prepared by in-situ growth method, and the Al ₂ O ₃ sphere is not only used as a catalyst carrier but also used as an Al ³⁺ source for in-situ growth of a precursor of NiAl-LDHs, through NiMAl. The precursor of LDHs obtains a NiM/Al ₂ O ₃ alloy catalyst, which not only improves the conversion of styrene, but also improves the selectivity of ethylbenzene, thereby improving the selective hydrogenation performance of pyrolysis gasoline. Moreover, the catalyst preparation process does not require the use of organic solvents or additives, and the method is simple and environmentally friendly.

DRAWINGS

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a SEM photograph (a, c) and a SEM photograph (b, d) of Example 12 Ni1CoAl-LDHs/Al ₂ O ₃ (a, b) and LP-2Ni1CoO/Al ₂ O ₃ (c, d) And a dark field scanning transmission electron micrograph of LP-2Ni1Co/Al ₂ O ₃ and a corresponding line scan of the metal particles (e).

2 is a γ-Al ₂ O ₃ carrier (a), a NiAl-LDHs/Al ₂ O ₃ (b) precursor, and a Ni:Co mass fraction ratio of 3:1 (c), 2:1 in Example 1. (d), XRD pattern of the mNinCoAl-LDHs/Al ₂ O ₃ precursor and the CoAl-LDHs/Al ₂ O ₃ precursor (f) of 1:1 (e).

3 is LP-Ni/Al ₂ O ₃ (a, b), LP-2Ni1Co/Al ₂ O ₃ (c, d), LP-1Ni1Co/Al ₂ O ₃ (e, f) and IM in Example 1. A photograph of a high resolution transmission electron microscope of -2Ni1Co/Al ₂ O ₃ (g, h). The particle size distribution is shown in the figure (calculated based on 150 particles per sample).

4 is a styrene conversion rate of a supported high-dispersion nickel-based alloy catalyst, LP-Ni/Al ₂ O ₃ catalyst, LP-Co/Al ₂ O ₃ catalyst, and IM-NiCo/Al ₂ O ₃ catalyst in Example 1. - the curve of time.

Figure 5 is a graph showing the stability of styrene conversion and selectivity-time of the LP-2Ni1Co/Al ₂ O ₃ catalyst in Example 1.

detailed description

Example 1

A. 5g of γ-Al ₂ O ₃ particles with a particle size of 20-40 mesh, Ni(NO ₃ ) ₂ ·6H ₂ O, Co(NO ₃ ) ₂ ·6H ₂ O, urea, quickly added to 10ml of deionized water , Ni and Co total mass fraction is 12wt%, different Ni/Co mass fraction ratio (m/n=3/1, 2/1, 1/1), urea: (Ni ²⁺ +Co ²⁺ ) The ratio is 2:1, and after vacuum impregnation for 1 h, it is transferred to an autoclave, crystallized at 130 ° C for 24 h, filtered, and the particles are washed with deionized water to a pH of 7, to obtain a supported high-dispersion NiCoAl-LDHs/Al ₂ O. ₃ precursors (SEM and XRD spectra are shown in Figures 1 and 2);

B. The NiCoAl-LDHs/Al ₂ O ₃ precursor was dried at 70 ° C for 10 h and then calcined at 450 ° C for 4 h to obtain LP-NiCoO/Al ₂ O ₃ ;

C. The LP-NiCoO/Al ₂ O ₃ prepared in step B was packed in a micro fixed bed reactor, heat treated at 500 ° C for 0.5 h under N ₂ protection, and the heating rate was 10 ° C / min; finally, the flow rate was 50 mL / The H _{2 of} min and the N ₂ mixture with a flow rate of 30 mL/min were reduced, the reduction temperature was 500 ° C, the reduction time was 3 h, and the reduction pressure was 0.5 MPa. After completion, the supported high-dispersion nickel-based alloy catalyst was obtained. It is LP-NiCo/Al ₂ O ₃ .

The process conditions for the selective hydrogenation reaction of the supported high-dispersion nickel-based alloy catalyst prepared above for pyrolysis gasoline are as follows: a catalyst dosage of 1.1 g, a reaction temperature of 40-60 ° C, a volume ratio of hydrogen to pyrolysis gasoline of 80, mass The airspeed WHSV=30h ^-1 , the total reaction pressure is 3.0MPa, the partial pressure of hydrogen is 0.4-3.0MPa, and the reaction time is 12h. The pyrolysis gasoline simulant composition used was 10 wt% of styrene, 35 wt% of toluene and 55 wt% of n-heptane, and the reaction product was analyzed by gas chromatography.

The conversion of styrene was investigated under the conditions of active component ratio and reaction time, and the supported catalyst prepared by the conventional impregnation method was used as a control. The reaction conditions are as follows, and the styrene conversion rate varies with each condition as shown in Fig. 4 and Fig. 5:

a) Reaction temperature: 60 ° C, partial pressure of hydrogen: 2.0 MPa, Ni loading of 12.0 wt%, Co loading of 0 (no addition of Co salt), reaction time: 12 h. (Figure 4)

b) Reaction temperature: 60 ° C, partial pressure of hydrogen: 2.0 MPa, Ni loading of 9.0 wt%, Co loading of 3.0 wt%, reaction time: 12 h. (Figure 4)

c) Reaction temperature: 60 ° C, partial pressure of hydrogen: 2.0 MPa, Ni loading of 8.0 wt%, Co loading of 4.0 wt%, reaction time: 12 h. (Figure 4)

d) Reaction temperature: 60 ° C, partial pressure of hydrogen: 2.0 MPa, Ni loading of 6.0 wt%, Co loading of 6.0 wt%, reaction time: 12 h. (Figure 4)

e) Reaction temperature: 60 ° C, hydrogen partial pressure: 2.0 MPa, Ni loading is 0, Co loading is 12.0 wt% (no Ni salt added), reaction time: 12 h. (Figure 4)

f) Reaction temperature: 60 ° C, partial pressure of hydrogen: 2.0 MPa, Ni loading of 8.0 wt%, Co loading of 4.0 wt% (prepared by conventional impregnation method), reaction time: 12 h. (Figure 4)

g) Reaction temperature: 60 ° C, partial pressure of hydrogen: 2.0 MPa, Ni loading of 8.0 wt%, Co loading of 4.0 wt%, reaction time: 117 h. (Figure 5)

The obtained materials were characterized by SEM and XRD. The results are shown in Fig. 1 and Fig. 2. It can be seen from the figure that NiCoAl-LDHs are grown on the surface and cut surface of 2Ni1CoAl-LDHs/Al ₂ O _{3 ,} which are evenly distributed in a network.

The obtained material was subjected to HRETEM characterization, and the results are shown in Fig. 3. As can be seen from Fig. 3, in the obtained LP-2Ni1Co/Al ₂ O ₃ particles, the 1-4 nm particle size accounts for 63%, and LP-Ni/Al ₂ O ₃ It is 53%, while the impregnated sample IM-2Ni1Co/Al ₂ O ₃ accounts for 53% of the particles larger than 16 nm. (LP refers to the preparation by in situ growth method, and the IM described later refers to the conventional impregnation method)

The obtained material was subjected to STEM characterization, and the results are shown in Fig. 1(e). It can be seen from Fig. 1(e) that the obtained LP-2Ni1Co/Al ₂ O ₃ forms a NiCo alloy phase.

The supported high-dispersion nickel-based alloy catalyst provided by the invention is particularly suitable for the selective hydrogenation reaction of pyrolysis gasoline. Compared with the conventional impregnation method of IM-2Ni1Co/Al ₂ O ₃ catalyst and single metal LP-Ni/Al ₂ O ₃ catalyst, the results are shown in Figure 4 and Figure 5:

1) It can be seen from Fig. 4 that the conversion of styrene reaches the highest value of 100.0% with the addition of Co, and Co is added to LP-1Ni1Co/Al ₂ O ₃ , and the conversion rate is reduced to 88.7%, while LP-Co /Al ₂ O ₃ is only 10.6%. It can be seen that an appropriate amount of Co can improve the hydrogenation performance of the catalyst.

2) It can be seen from Fig. 4 that the conversion rate of the catalyst IM-2Ni1Co/Al ₂ O ₃ prepared by the conventional impregnation method is only 69.7% compared with the catalyst prepared by the in-situ growth method, which indicates that the catalyst prepared by the in-situ growth method It has excellent activity and stability, not only because it has a limited effect, but also has an excellent synergistic effect on the formed alloy phase. The confinement effect is manifested by the strong interaction between the active component and the carrier, the formation of the active component particles is also small, and the advantage of the small particle size is that it can inhibit the formation of carbon deposits. The formed alloy phase can improve the selectivity of the catalyst and also inhibit the formation of carbon deposits.

3) It can be seen from Fig. 4 that the alloy catalyst prepared by in-situ growth method has higher conversion and selectivity than LP-Ni/Al ₂ O ₃ than single metal catalyst, and it is known that the alloy catalyst has an alloy. High activity, high selectivity and high stability due to effects and synergistic effects.

4) It can be seen from Fig. 5 that the initial activity of LP-2Ni1Co/Al ₂ O ₃ is 100.0%, the reaction can be maintained at 93.2% after 117 hours, the selectivity is kept at 100.0%, and the carbon deposition value is only 2.76wt. %, and was 1.65 wt% after 12 hours of reaction. However, for the reaction of LP-Ni/Al ₂ O _{3 , the} reaction reached 2.43 wt% in 12 hours, and the IM-2Ni1Co/Al ₂ O ₃ reached 2.57 wt%. It is known that LP-2Ni1Co/Al ₂ O ₃ has excellent anti-product. Carbon properties.

Example 2

A. 5g of γ-Al ₂ O ₃ particles with a particle size of 20-40 mesh, Ni(NO ₃ ) ₂ ·6H ₂ O, Zn(NO ₃ ) ₂ ·6H ₂ O, urea, quickly added to 10ml of deionized water , Ni and Zn total mass fraction is 12wt%, different Ni/Zn mass fraction ratio (m/n=3/1, 2/1, 1/1), urea: (Ni ²⁺ +Zn ²⁺ ) The ratio is 2:1, and after vacuum impregnation for 1 h, it is transferred to an autoclave, crystallized at 130 ° C for 24 h, filtered, and the particles are washed with deionized water to a pH of 7, to obtain a supported high-dispersion NiZnAl-LDHs/Al ₂ O. ₃ precursors;

B. The NiZnAl-LDHs/Al ₂ O ₃ precursor was dried at 70 ° C for 10 h and then calcined at 450 ° C for 4 h to obtain LP-NiZnO/Al ₂ O ₃ ;

C. The LP-NiZnO/Al ₂ O ₃ prepared in step B was packed in a micro fixed bed reactor, heat treated at 500 ° C for 0.5 h under N ₂ protection, and the heating rate was 10 ° C / min; finally, the flow rate was 50 mL / The H _{2 of} min and the N ₂ mixture with a flow rate of 30 mL/min were reduced, the reduction temperature was 500 ° C, the reduction time was 3 h, and the reduction pressure was 0.5 MPa. After completion, the supported high-dispersion nickel-based alloy catalyst was obtained. It is LP-NiZn/Al ₂ O ₃ .

Example 3

A. 5g of γ-Al ₂ O ₃ particles with a particle size of 20-40 mesh, Ni(NO ₃ ) ₂ ·6H ₂ O, Cu(NO ₃ ) ₂ ·3H ₂ O, urea, quickly added to 10ml of deionized water , Ni and Cu total mass fraction is 12wt%, different Ni/Cu mass fraction ratio (m/n=3/1, 2/1, 1/1), urea: (Ni ²⁺ + Cu ²⁺ ) The ratio is 2:1, and after vacuum impregnation for 1 h, it is transferred to an autoclave, crystallized at 130 ° C for 24 h, filtered, and the particles are washed with deionized water to a pH of 7, to obtain a supported high-dispersion NiCuAl-LDHs/Al ₂ O. ₃ precursors;

B. The NiCuAl-LDHs/Al ₂ O ₃ precursor was dried at 70 ° C for 10 h and then calcined at 450 ° C for 4 h to obtain LP-NiCuO/Al ₂ O ₃ ;

C. The LP-NiCuO/Al ₂ O ₃ prepared in step B was packed in a micro fixed bed reactor, heat treated at 500 ° C for 0.5 h under N ₂ protection, and the heating rate was 10 ° C / min; finally, the flow rate was 50 mL / The H _{2 of} min and the N ₂ mixture with a flow rate of 30 mL/min were reduced, the reduction temperature was 500 ° C, the reduction time was 3 h, and the reduction pressure was 0.5 MPa. After completion, the supported high-dispersion nickel-based alloy catalyst was obtained. It is LP-NiCu/Al ₂ O ₃ .

Example 4

A. 5g of γ-Al ₂ O ₃ particles with a particle size of 20-40 mesh, Ni(NO ₃ ) ₂ ·6H ₂ O, Fe(NO ₃ ) ₃ ·9H ₂ O, urea, quickly added to 10ml of deionized water , Ni and Fe total mass fraction is 12wt%, different Ni/Fe mass fraction ratio (m/n=3/1, 2/1, 1/1), urea: (Ni ²⁺ + Fe ³⁺ ) The ratio is 2:1, and after vacuum impregnation for 1 h, it is transferred to an autoclave, crystallized at 130 ° C for 24 h, filtered, and the particles are washed with deionized water to a pH of 7, to obtain a supported type of highly dispersed NiFeAl-LDHs/Al ₂ O. ₃ precursors;

B. The NiFeAl-LDHs/Al ₂ O ₃ precursor was dried at 70 ° C for 10 h and then calcined at 450 ° C for 4 h to obtain LP-NiFeO/Al ₂ O ₃ ;

C. The LP-NiFeO/Al ₂ O ₃ prepared in step B was packed in a micro fixed bed reactor, heat treated at 500 ° C for 0.5 h under N ₂ protection, and the heating rate was 10 ° C / min; finally, the flow rate was 50 mL / The H _{2 of} min and the N ₂ mixture with a flow rate of 30 mL/min were reduced, the reduction temperature was 500 ° C, the reduction time was 3 h, and the reduction pressure was 0.5 MPa. After completion, the supported high-dispersion nickel-based alloy catalyst was obtained. It is LP-NiFe/Al ₂ O ₃ .

Example 5

A. 5g of γ-Al ₂ O ₃ particles with a particle size of 20-40 mesh, Ni(NO ₃ ) ₂ ·6H ₂ O, Cr(NO ₃ ) ₃ ·9H ₂ O, urea, quickly added to 10ml of deionized water , Ni and Cr total mass fraction is 12wt%, different Ni/Cr mass fraction ratio (m/n=3/1, 2/1, 1/1), urea: (Ni ²⁺ +Zn ²⁺ ) The ratio is 2:1, vacuum impregnation 1 is transferred to the autoclave, crystallized at 130 ° C for 24 h, filtered, and the particles are washed with deionized water to a pH of 7, to obtain a supported type of highly dispersed NiCrAl-LDHs/Al ₂ O. ₃ precursors;

B. The NiCrAl-LDHs/Al ₂ O ₃ precursor was dried at 70 ° C for 10 h and then calcined at 450 ° C for 4 h to obtain LP-NiCrO/Al ₂ O ₃ ;

C. The LP-NiCrO/Al ₂ O ₃ prepared in step B was packed in a micro fixed bed reactor, heat treated at 500 ° C for 0.5 h under N ₂ protection, and the heating rate was 10 ° C / min; finally, the flow rate was 50 mL / The H _{2 of} min and the N ₂ mixture with a flow rate of 30 mL/min were reduced, the reduction temperature was 500 ° C, the reduction time was 3 h, and the reduction pressure was 0.5 MPa. After completion, the supported high-dispersion nickel-based alloy catalyst was obtained. It is LP-NiCr/Al ₂ O ₃ .

Claims

A supported high-dispersion nickel-based alloy catalyst characterized in that the composition of the alloy is: the alloy NiM is distributed on the outer surface of the γ-Al 2 O 3 carrier particles and the pores thereof to form a distributed high-dispersion alloy distribution; the alloy NiM particles The diameter of the γ-Al 2 O 3 carrier is 20-40 mesh; the total loading of the alloy NiM is 6-12 wt% based on the total mass of the catalyst; M is Co, Zn, Cu, Fe or Cr. .
The method for preparing a supported high-dispersion nickel-based alloy catalyst according to claim 1, wherein the specific operation steps are as follows:

A. 3-5g γ-Al 2 O 3 particles with a particle size of 20-40 mesh, soluble nickel salt, soluble M salt, urea, quickly added to 10ml deionized water, vacuum impregnation for 1-3h and transferred to the autoclave Crystallizing at a temperature of 90-130 ° C for 12-24 h, filtering, washing the particles with deionized water to obtain a supported high-dispersion NiMAl-LDHs/Al 2 O 3 precursor;

B. The NiMAl-LDHs/Al 2 O 3 precursor is dried at 60-100 ° C for 6-12 h, then calcined at 400-600 ° C for 2-8 h to obtain LP-NiMO/Al 2 O 3 ;

C. The LP-NiMO/Al 2 O 3 prepared in step B is packed in a micro fixed bed reactor, heat treated at 400-600 ° C for 0.5-2 h under N 2 protection, and the heating rate is 5-10 ° C / min; The reduction is carried out by using a mixture of H 2 having a flow rate of 30-80 mL/min and N 2 having a flow rate of 10-30 mL/min, a reduction temperature of 400-600 ° C, a reduction time of 2-5 h, and a reduction pressure of 0.5-1 MPa. Upon completion, a supported high dispersion nickel-based alloy catalyst is obtained.
The preparation method according to claim 2, wherein the molar ratio of urea to metal ions in the step A is (2:1)-(4:1).
The method according to claim 2, wherein the soluble nickel salt is nickel nitrate, nickel chloride or nickel sulfate.
The preparation method according to claim 2, wherein the soluble M salt is nitric acid M, chlorinated M or sulfuric acid M.
The use of a supported high-dispersion nickel-based alloy catalyst prepared by the method according to claim 2 for catalytically cracking gasoline in a selective hydrogenation reaction.
The use according to claim 6, wherein the catalytic cracking gasoline has a selective hydrogenation reaction condition: a reaction temperature of 40-60 ° C, a volume ratio of hydrogen to pyrolysis gasoline of 50-100, mass The space velocity WHSV=10-30h -1 , the amount of catalyst is 1.0-1.5g, the total reaction pressure is 2.0-3.5MPa, the partial pressure of hydrogen is 0.4-3.0MPa, and the reaction time is 12-120h.