Transition metal-modified nickel hydrogenation catalyst and method for preparing the same

Abstract

The application belongs to the technical field of catalytic hydrogenation, and particularly relates to a transition metal regulated nickel hydrogenation catalyst and a preparation method thereof. a O b @N, 1<=a<=2, 1<=b<=2; the application adopts a step-by-step impregnation load-controllable calcination reduction method, regulates the performance of nickel by a non-noble transition metal, realizes high dispersion and anchoring of nickel nanocrystalline grains, and greatly improves the catalytic hydrogenation activity and stability of the nickel; the application is simple in preparation method, low in cost, and less in required nickel source, and the prepared active metal nanoparticles are uniformly and stably present and can be prepared in batches; the application effectively solves the problems that current commercial hydrogenation catalysts are noble metals, resources are scarce, costs are high, and large-scale preparation is difficult to realize, and is suitable for catalyzing hydrogenation of organic unsaturated compounds containing C=C, C=O double bonds and the like.

Description

Technical Field

[0001] This invention belongs to the field of catalytic hydrogenation technology, specifically relating to a transition metal-controlled nickel hydrogenation catalyst and its preparation method. Background Technology

[0002] Catalytic hydrogenation is a very common chemical reaction with important applications in petroleum, chemical, and pharmaceutical fields. The selective hydrogenation of aromatic organic compounds, in particular, is crucial for industrial development. Furthermore, organic liquid hydrogen storage materials are liquid organic compounds at room temperature, enabling safe storage and transportation of hydrogen under ambient temperature and pressure, making them one of the most promising hydrogen storage technologies. Their outstanding advantages lie in high hydrogen storage density, non-flammability, non-explosiveness, safety, and reliability, making them compatible with existing petroleum transportation infrastructure. Therefore, using them as hydrogen storage carriers for catalytic hydrogenation is a key aspect of hydrogen storage technology. Currently, commercial precious metal catalysts such as Pt, Pd, Ru, Rh, and Ir are commonly used for the aforementioned catalytic hydrogenation applications. However, due to their scarcity and non-renewability, these precious metals are expensive, resulting in high costs. Therefore, in industry, precious metals are often loaded onto ordinary supports or form organometallic complexes. However, because precious metal catalysts are very reactive, side reactions often occur during the reaction process. On the one hand, this leads to a decrease in catalytic selectivity and increases the cost of material separation and purification; on the other hand, it often causes frequent catalyst poisoning, resulting in catalyst deactivation.

[0003] To address these issues, researchers have developed numerous novel catalysts, including those based on non-precious metals. However, non-precious metal catalysts also suffer from problems such as low specific surface area, insufficient activity, and a tendency to agglomerate. These intrinsic defects severely limit their application. For example, the most widely used Raney nickel hydrogenation catalyst has a large specific surface area and a large amount of activated hydrogen on its surface. However, nickel itself is highly reactive and prone to agglomeration, resulting in larger particles. This typically requires protection using organic solvents or passivation methods, and the catalyst must be reduced again before use, a cumbersome process that makes it difficult to maintain sufficient stability. These problems remain a significant challenge in the catalytic hydrogenation industry and hinder the large-scale application of hydrogen energy technology.

[0004] Therefore, it is necessary to provide a novel catalyst and its preparation method that possesses high catalytic activity and selectivity while maintaining the stable presence of the active components. Ultimately, this will further promote the development of the catalytic hydrogenation industry and hydrogen energy applications. Summary of the Invention

[0005] The purpose of this invention is to overcome the above-mentioned problems existing in the conventional technology and provide a highly efficient transition metal-controlled nickel hydrogenation catalyst and its preparation method that does not require any precious metals. The method involves covering a porous material support with a transition metal oxide with a variable valence state and forming a suboxide morphology through controllable reduction, thereby achieving a significant improvement in the catalytic performance of nickel.

[0006] To achieve the above-mentioned technical objectives and effects, the present invention is implemented through the following technical solution:

[0007] This invention provides a transition metal-controlled nickel hydrogenation catalyst with a Ni-M composition. a O b @N, 1≤a≤2, 1≤b≤2; where,

[0008] Ni is the main catalyst, and the molar percentage content of the main catalyst is 0.1% to 25%.

[0009] M is the main catalyst regulator, including any one or more combinations of Co, Cu, Fe, Mn, Cr, Mo, W, V, Zr, and La, and the molar percentage content of the main catalyst regulator is 0.1% to 25%.

[0010] The carrier is N, which includes any one or more combinations of porous C materials, porous transition metal oxides and porous non-metal oxides, with a molar percentage content of 50% to 99.8%.

[0011] Furthermore, the Ni nanoparticles of the main catalyst are highly dispersed on the main catalyst modifier M and anchored in a partially NiM alloyed form.

[0012] Furthermore, the main catalyst regulator M is a transition metal element existing in a subvalence state, which anchors the support with oxygen atoms as anchor points.

[0013] Furthermore, the main catalyst modifier M can effectively refine the size of active metal Ni nanocrystals and regulate their electronic structure.

[0014] Furthermore, the nanocrystal size of the main catalyst Ni can be controlled between 2 nm and 12 nm by the regulation effect of the main catalyst regulator M.

[0015] Furthermore, the specific surface area of ​​the carrier N is 80–300 m². 2 / g.

[0016] This invention also provides a method for preparing a transition metal-controlled nickel hydrogenation catalyst, comprising the following steps:

[0017] 1) Weigh a certain amount of Ni and M precursor and prepare Ni precursor solution and M precursor solution of a certain concentration respectively, and denot them as solution A and solution B respectively;

[0018] 2) Weigh a certain amount of N and add it to solution B, mix well, and dry thoroughly at 50-70℃ until no visible water remains. Then, calcine thoroughly at 300-600℃ to obtain M with a uniform surface coating of M oxide. x O y @N-type carrier, 1≤x≤3, 1≤y≤4;

[0019] 3) Take a certain amount of solution A and add it to the above M. x O y In an N-type carrier, the mixture was stirred until homogeneous, ultrasonically treated, and then heated and stirred at 50–80°C until no visible water remained. It was then further dried overnight, followed by calcination and reduction at 300–600°C to obtain Ni-M. a O b @N-type hydrogenation catalyst.

[0020] Further, in step 1), the Ni precursor includes any one or more combinations of Ni nitrate, acetate, and halide salts.

[0021] Further, in step 1), the M precursor includes any one or more combinations of ferric nitrate, ferric chloride, cobalt nitrate, cobalt chloride, nickel nitrate, nickel chloride, copper nitrate, copper chloride, chromium chloride, chromium nitrate, manganese chloride, manganese nitrate, zirconium chloride, zirconium nitrate, ammonium molybdate, sodium molybdate, ammonium metavanadate, ammonium metatungstate, sodium tungstate, sodium metatungstate, sodium metavanadate, sodium metavanadate, cerium nitrate, and lanthanum nitrate.

[0022] Furthermore, in step 2), the mixture is thoroughly stirred at 60°C and then fully calcined at 350–550°C.

[0023] Furthermore, in step 3), the mixture is thoroughly stirred at 70°C and then fully calcined at 350–550°C.

[0024] Furthermore, in step 3), the reduction temperature is 350℃~500℃, and the reduction time is 60~180min.

[0025] This invention also provides the application of transition metal-regulated nickel hydrogenation catalysts in the catalytic hydrogenation of C=C and C=O double bonds.

[0026] The beneficial effects of this invention are:

[0027] 1. This invention uses a non-noble transition metal element with variable valence as a modifier for the main catalyst Ni. On the one hand, it anchors highly dispersed Ni nanoparticles through contact surface alloying, reducing their agglomeration tendency and refining the grain size of the active metal to obtain more active sites, thereby improving catalyst activity. On the other hand, the variable valence transition metal element exists in the form of suboxides, regulating the electronic structure of Ni, thereby improving catalyst selectivity and stability, making the catalyst's catalytic activity comparable to noble metal catalysts. Furthermore, it outperforms noble metal catalysts in terms of selectivity, exhibiting no side reactions. It enables low-temperature, controllable, and rapid hydrogenation of organic unsaturated compounds containing C=C and C=O double bonds without significant side reactions.

[0028] 2. All raw materials for the catalyst of this invention are non-precious metal compounds, which are widely available, inexpensive, simple to process, short in cycle, and have high yield. They can significantly improve the catalytic performance and stability of hydrogenation catalysts, effectively extend the service life of catalysts, thereby reducing the cost of hydrogenation reaction and enabling industrial-scale catalytic hydrogenation applications.

[0029] Of course, any product implementing this invention does not necessarily need to achieve all of the above advantages at the same time. Detailed Implementation

[0030] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] This invention first employs a stepwise impregnation-loading-controlled calcination-reduction method to modulate the performance of nickel using a non-noble transition metal, achieving high dispersion and anchoring of nickel nanocrystals and enhancing catalytic hydrogenation activity. This invention not only features a simple and easy-to-operate preparation method, requiring less nickel source, resulting in low cost and stable process, but also produces uniform and stable active metal Ni nanoparticles suitable for mass production. It effectively solves the problems of current commercial hydrogenation catalysts being precious metals, characterized by resource scarcity, high cost, and difficulty in large-scale production. It is suitable for hydrogenation applications catalyzing organic unsaturated compounds containing C=C, C=O double bonds, etc.

[0032] Specific embodiments of the present invention are as follows:

[0033] Example 1

[0034] A portion of porous carbon was weighed out, and the prepared ammonium molybdate precursor solution was impregnated and loaded onto the porous carbon in a molar ratio of Ni:M:N = 1:0.5:8.5. The mixture was stirred until homogeneous and thoroughly dried at 60°C until no visible water remained. Then, it was calcined at 550°C to obtain MoO3@C powder. The prepared nickel acetate precursor solution was then impregnated and loaded onto MoO3@C, stirred until homogeneous, and ultrasonically treated. Afterward, it was heated and stirred at 70°C until no visible water remained, and then further dried overnight. Subsequently, it was calcined at 500°C for 3 hours and then transferred to a H2 atmosphere for reduction at 450°C for 120 minutes. Finally, a Ni-MoO2@C hydrogenation catalyst with a grain size distribution of approximately 5.8 nm was obtained.

[0035] The reaction was carried out in a hydrogenation reactor at a ratio of active metal to reactant of 1:200, at 25–150 °C and a hydrogen pressure of 0.5–2 MPa for 6 h. The results are shown in Table 1.

[0036] Table 1

[0037]

[0038] Example 2

[0039] A portion of porous silica was weighed, and a molar ratio of Ni:M:N = 0.5:1:8.5 was used to impregnate the porous silica with a prepared manganese nitrate precursor solution. The mixture was stirred until homogeneous and thoroughly dried at 60°C until no visible water remained. Then, it was calcined at 500°C to obtain MnO2@SiO2 powder. A prepared nickel chloride precursor solution was then impregnated with MnO2@SiO2, stirred until homogeneous, and ultrasonically treated. Afterward, it was heated and stirred at 70°C until no visible water remained, then further dried overnight. Subsequently, it was calcined at 500°C for 4 hours and then transferred to a H2 atmosphere for reduction at 500°C for 180 minutes. Finally, a Ni-MnO@SiO2 hydrogenation catalyst with a grain size distribution of approximately 4.6 nm was obtained.

[0040] The reaction was carried out in a hydrogenation reactor at a ratio of active metal to reactant of 1:200, at 120–200 °C and 7 MPa hydrogen pressure for 6 h. The results are shown in Table 2.

[0041] Table 2

[0042]

[0043] Example 3

[0044] A portion of porous alumina was weighed out, and the prepared ferric nitrate precursor solution was impregnated and loaded onto the porous alumina in a molar ratio of Ni:M:N = 2:1:7. The mixture was stirred until homogeneous and thoroughly dried at 70°C until no visible water remained. Then, it was calcined at 500°C to obtain Fe2O3@Al2O3 powder. A prepared nickel nitrate precursor solution was then impregnated and loaded onto Fe2O3@Al2O3, stirred until homogeneous, and ultrasonically treated. Afterward, it was heated and stirred at 70°C until no visible water remained, and then further dried overnight. Subsequently, it was calcined at 450°C for 3 hours and then transferred to a H2 atmosphere for reduction at 450°C for 150 minutes. Finally, a Ni-FeO@Al2O3 hydrogenation catalyst with a grain size distribution of approximately 7.5 nm was obtained.

[0045] The reaction was carried out in a hydrogenation reactor at a ratio of active metal to reactant of 1:200, at 120–200 °C and 7 MPa hydrogen pressure for 6 h. The results are shown in Table 3.

[0046] Table 3

[0047]

[0048]

[0049] Comparative Example 1

[0050] Weigh out a portion of porous alumina, with a molar ratio of Ni:N = 2:8, impregnate the prepared nickel nitrate precursor solution onto Al2O3, stir evenly, sonicate, heat and stir at 70℃ until no visible water is visible, then dry overnight, calcine at 450℃ for 3 hours, and then transfer to H2 atmosphere for reduction at 450℃ for 150 minutes. Finally, a Ni@Al2O3 hydrogenation catalyst with a grain size distribution of about 42 nm is obtained.

[0051] In addition, a set of hydrogenation test results for the commercial precious metal Ru / Al2O3 were added under the same conditions.

[0052] Subsequently, the reaction was carried out in a hydrogenation reactor at an active metal:reactant ratio of 1:200, at 120–200 °C and 8 MPa hydrogen pressure for 6 h. The results are shown in Table 4.

[0053] Table 4

[0054]

[0055]

[0056] As can be seen from the results of the above three sets of examples and one set of comparative examples, the introduction of non-noble transition metal elements to regulate the performance of nickel effectively achieves the refinement and stability of nickel nanocrystals, and greatly improves the catalytic performance of the hydrogenation catalyst. Therefore, this invention provides a highly efficient transition metal-regulated nickel hydrogenation catalyst and its preparation method.

[0057] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to specific implementations. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A transition metal-modulated nickel hydrogenation catalyst characterized in that, The catalyst composition is Ni-M a O b @N, 1≤a≤2, 1≤b≤2; wherein, Ni is the main catalyst, the molar percentage content of which is 0.1%-25%; M is the main catalyst modifier, including any one or more combinations of Co, Cu, Fe, Mn, Cr, Mo, W, V, Zr, La, the molar percentage content of which is 0.1%-25%; N is the carrier, including any one or more combinations of porous C material, porous transition metal oxide and porous non-metallic oxide, the molar percentage content of which is 50%-99.8%; The preparation method of the catalyst comprises the following steps: 1) A certain amount of Ni and M precursors are respectively prepared into a certain concentration of Ni precursor solution and M precursor solution, respectively denoted as A solution and B solution; 2) Weigh a certain amount of N into B solution, mix, stir evenly, dry at 50-70°C until no visible water, then calcine at 300-600°C to obtain M x O y @N-type carrier, 1≤x≤3, 1≤y≤4; 3) Take a certain amount of A solution to the above M x O y @In N-type carrier, stirring, after ultrasonic treatment, heated stirring until no visible water, further drying overnight, then at 300-600 ℃ temperature first calcination and then reduction, to get Ni-M a O b @N-type hydrogenation catalyst.

2. The transition metal-modulated nickel hydroprocessing catalyst of claim 1, wherein, The nanoparticles of the main catalyst Ni are highly dispersed on the main catalyst modifier M and anchored in the form of partial NiM alloying.

3. The transition metal-modulated nickel hydroprocessing catalyst of claim 1, wherein, The main catalyst modifier M is a transition metal element existing in a subvalence state and anchors the carrier with oxygen atoms as anchor points.

4. The transition metal-modulated nickel hydroprocessing catalyst of claim 1, wherein, The main catalyst modifier M can effectively refine the nanocrystalline grain size of the active metal Ni and regulate its electronic structure.

5. The transition metal-modulated nickel hydroprocessing catalyst of claim 1, wherein, The nanocrystalline grain size of the main catalyst Ni can be controlled between 2 nm and 12 nm through the regulation of the main catalyst modifier M.

6. The transition metal-modulated nickel hydroprocessing catalyst of claim 1, wherein, The specific surface area of the support N is between 80 and 300 m 2 / g.

7. The transition metal-modulated nickel hydroprocessing catalyst of claim 1, wherein, In step 1), the Ni precursor includes any one or more combinations of nitrate, acetate and halide of Ni.

8. The transition metal-modulated nickel hydroprocessing catalyst of claim 1, wherein, In step 1), the M precursor includes any one or more combinations of iron nitrate, iron chloride, cobalt nitrate, cobalt chloride, nickel nitrate, nickel chloride, copper nitrate, copper chloride, chromium chloride, chromium nitrate, manganese chloride, manganese nitrate, zirconium chloride, zirconium nitrate, ammonium molybdate, sodium molybdate, ammonium metavanadate, ammonium metatungstate, sodium tungstate, sodium metatungstate, sodium vanadate, sodium metavanadate, cerium nitrate and lanthanum nitrate.

9. Application of the transition metal-regulated nickel hydrogenation catalyst according to any one of claims 1-6 in catalyzing C=C and C=O double bond hydrogenation reaction.

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