Nitrogen-modified carrier and preparation method thereof, nitrogen-modified carrier-loaded bimetallic heterogeneous catalyst and preparation method and application of nitrogen-modified carrier-loaded bimetallic heterogeneous catalyst

Abstract

The invention relates to the technical field of catalysts, and provides a nitrogen modified carrier and a preparation method thereof, a nitrogen modified carrier loaded bimetallic heterogeneous catalyst and a preparation method and application thereof. The preparation method of the nitrogen-modified carrier comprises the following steps: carrying out nitrogen modification treatment on a solid-phase carrier by using a nitrogen modifier comprising alginic acid and weak acid ammonium salt to prepare the nitrogen-modified carrier, the mass ratio of the alginic acid to the weak acid ammonium salt is 1: (0.1-1.2); the mass ratio of the alginic acid to the solid phase carrier is (0.05-1.5): 1. The heterogeneous catalyst is prepared by loading bimetallic on the nitrogen modified carrier, the preparation method is simple, and an expensive phosphorus-containing organic ligand does not need to be used; compared with the existing bimetallic heterogeneous catalyst, the prepared catalyst has better catalytic performance, has excellent catalytic performance on olefin hydroformylation, especially high-carbon olefin hydroformylation reaction, and has good stability.

Description

Technical Field

[0001] The present invention relates to the field of catalyst technology, and more specifically, to a nitrogen-modified carrier and a preparation method thereof, a bimetallic heterogeneous catalyst supported by a nitrogen-modified carrier and a preparation method and application thereof. Background Art

[0002] Hydroformylation is the process of reacting olefins with synthesis gas (CO / H2) to produce aldehydes. The aldehyde groups generated by hydroformylation can be further converted into imines, amines, hemiacetals, acetals, aminals, carboxyl groups, hydroxyl groups, and other groups. Aldehydes produced by hydroformylation are widely used in the synthesis of fine chemicals such as plasticizers, surfactants, pharmaceuticals, pesticides, and flavorings. The growing demand for aldehydes and alcohols in the chemical industry, coupled with the abundant supply of inexpensive olefins from the petroleum industry, has driven the rapid development of hydroformylation.

[0003] Currently, hydroformylation reactions in my country still rely on homogeneous catalysts, primarily rhodium-phosphine complexes. While these catalysts offer high activity and selectivity, subsequent separation and processing are difficult and costly, particularly for long-chain olefin reactions. While heterogeneous hydroformylation catalysts offer the advantage of easier separation, they also suffer from low space-time yields and poor thermodynamic stability, making them difficult to meet industrial demands. Therefore, achieving efficient and stable heterogeneous catalytic hydroformylation reactions is a current research hotspot in this field.

[0004] CN116174050A provides a heterogeneous catalyst composed of a phosphine-containing organic polymer self-supporting a metal component, wherein the phosphine-containing organic polymer is an organic polymer with a multi-level porous structure formed by the polymerization of a vinyl-containing monodentate organophosphine ligand. The organic polymer has the dual functions of a carrier and a ligand. On the one hand, the metal component can be highly dispersed and loaded in the multi-level porous structure and / or on the surface, thereby exposing more catalytic active sites; on the other hand, the high concentration of phosphorus in the polymer backbone easily forms multiple coordination bonds with the metal component, which helps to reduce the loss of active components. Therefore, the catalyst exhibits good catalytic activity and stability in the hydroformylation reaction of 1-octene. CN114870901A provides a porous phosphine-containing organic polymer-supported heterogeneous catalyst similar to CN116174050A, but the phosphine-containing organic polymer is obtained by the polymerization of two or more vinyl-containing bidentate organophosphine ligand monomers and aromatic compounds containing olefin functional groups, wherein the bidentate structure can promote the bidentate chelation of the active metal and the ligand, thereby further improving the stability of the active metal in the hydroformylation of olefins. Although the above-mentioned catalysts have great potential in solving the problems of low space-time yield and poor thermodynamic stability in hydroformylation reactions, the preparation process requires the introduction of expensive phosphine-containing ligands, which is cumbersome. In addition, the phosphorus-containing waste generated during the preparation and use is environmentally unfriendly, which greatly restricts the industrial development of hydroformylation reactions.

[0005] Therefore, developing a method for preparing highly active and stable heterogeneous catalysts without using phosphine-containing ligands is particularly important for hydroformylation reactions and various heterogeneous catalytic reactions in petrochemicals. Summary of the Invention

[0006] The present invention aims to provide a nitrogen-modified support and a preparation method thereof, and a bimetallic heterogeneous catalyst supported on a nitrogen-modified support and a preparation method and application thereof, so as to solve the technical problems in the prior art of hydroformylation heterogeneous catalysts, such as low activity and poor stability, the need to use phosphine-containing ligands for preparation, high cost, and environmentally unfriendly phosphorus waste.

[0007] To achieve the above object, the technical solution adopted by the present invention is:

[0008] In a first aspect, the present invention provides a method for preparing a nitrogen-modified carrier, comprising: performing nitrogen-modification treatment on a solid phase carrier using a nitrogen modifier comprising alginic acid and a weak acid ammonium salt to obtain the nitrogen-modified carrier;

[0009] The mass ratio of alginic acid to weak acid ammonium salt is 1:(0.1-1.2), preferably 1:(0.5-1.0);

[0010] The mass ratio of the alginic acid to the solid phase carrier is (0.05-1.5):1, preferably (0.2-1):1.

[0011] Alginic acid ((C6H8O6) n ) is a natural polysaccharide uronic acid, a linear copolymer formed by 1,4-bonding of β-D-mannuronic acid and α-L-guluronic acid, which can react with weak acid ammonium salts to form ammonium alginate, thereby achieving nitrogen modification of the solid phase carrier.

[0012] According to some embodiments of the present invention, the weak acid ammonium salt includes at least one of (NH4)2CO3, NH4HCO3, and NH4OH.

[0013] Preferably, the weak acid ammonium salt comprises (NH4)2CO3 and / or NH4OH.

[0014] More preferably, the weak acid ammonium salt comprises (NH4)2CO3.

[0015] In the present invention, compared with other types of nitrogen sources (including other types of weak acid ammonium salts), using (NH4)2CO3 as a nitrogen source to prepare a nitrogen-modified carrier can make the performance of the finally prepared catalyst better.

[0016] According to some embodiments of the present invention, the solid phase carrier includes at least one of oxides (such as Al2O3, SiO2, etc.), carbon materials (such as carbon black, etc.), molecular sieves (such as SBA-15, etc.), and MOFs.

[0017] According to some embodiments of the present invention, the oxide includes metal oxides and non-metal oxides.

[0018] Preferably, the solid support comprises Al2O3.

[0019] More preferably, the solid support comprises γ-Al2O3.

[0020] According to some embodiments of the present invention, the particle size of the solid phase carrier is ≤100 μm, and the specific surface area is ≥200 m 2 / g.

[0021] According to some embodiments of the present invention, the particle size of the solid phase carrier is 30 to 100 μm, and the specific surface area is 200 to 250 m 2 / g.

[0022] According to some embodiments of the present invention, the preparation method of the nitrogen-modified carrier includes: dispersing alginic acid, a weak acid ammonium salt and a solid phase carrier in water, stirring and mixing, separating the solid phase and the liquid phase, evaporating the water from the solid phase, crushing, and performing a first calcination treatment to obtain the nitrogen-modified carrier.

[0023] In the preparation method of the nitrogen-modified carrier, the degree of stirring and mixing will affect the effect of the solid phase carrier and alginic acid and weak acid ammonium salt, and have a relatively obvious impact on the performance of the prepared nitrogen-modified carrier. It is necessary to stir for an appropriate length of time under appropriate temperature conditions.

[0024] According to some embodiments of the present invention, the stirring and mixing temperature is 0 to 60° C., preferably 20 to 40° C.; the stirring and mixing time is 0.5 to 20 h, preferably 6 to 15 h, more preferably 8 to 12 h.

[0025] In the present invention, various common methods can be used to evaporate the water in the solid phase, such as forced air drying, vacuum drying, etc.

[0026] In the present invention, the purpose of pulverizing the obtained solid is to disperse the solid agglomerated during the volatilization of water, so as to make the particles of the nitrogen-modified carrier more uniform. Various common operations that can disperse the solid, such as grinding, can be used.

[0027] According to some embodiments of the present invention, the method for preparing the nitrogen-modified carrier further comprises: washing the solid phase and then evaporating the water.

[0028] According to some embodiments of the present invention, the heating rate of the first calcination treatment is 1-30°C / min, preferably 5-25°C / min; the temperature of the first calcination treatment is 400-1000°C, preferably 600-900°C; the time of the first calcination treatment is 0.5-10h, preferably 2-8h.

[0029] In the present invention, the first calcination treatment is carried out at a suitable temperature, which is beneficial to the modification of the solid phase carrier by nitrogen.

[0030] In a second aspect, the present invention provides a nitrogen-modified carrier prepared by the preparation method described in the first aspect.

[0031] According to some embodiments of the present invention, the nitrogen content in the nitrogen-modified carrier is 0.8-18.0 wt%, for example, it can be 0.8 wt%, 1 wt%, 2 wt%, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, 10 wt%, 11 wt%, 12 wt%, 13 wt%, 14 wt%, 15 wt%, 16 wt%, 17 wt%, 18 wt%, etc.

[0032] Preferably, the nitrogen content in the nitrogen-modified carrier is 4.5 to 15.0 wt%.

[0033] In a third aspect, the present invention provides a bimetallic heterogeneous catalyst supported on a nitrogen-modified carrier, comprising a nitrogen-modified carrier prepared by the preparation method described in the first aspect or the nitrogen-modified carrier described in the second aspect, an active metal and an auxiliary metal; the active metal and the auxiliary metal are supported on the nitrogen-modified carrier.

[0034] The bimetallic heterogeneous catalyst supported on a nitrogen-modified carrier provided by the present invention uses a carrier that has been nitrogen-modified with alginic acid and a weak acid ammonium salt, which can effectively coordinate with the active metal and the auxiliary metal, thereby facilitating the efficient loading of the active metal and improving the catalytic activity and stability of the catalyst.

[0035] Compared with nitrogen-modified supports prepared by other prior art methods, the nitrogen-modified support prepared by using alginic acid and weak acid ammonium salt is more advantageous for improving the catalytic activity and stability of the catalyst.

[0036] According to some embodiments of the present invention, the active metal includes at least one of Rh, Pb, Ir, Ru, and Au.

[0037] Preferably, the active metal includes Rh.

[0038] In the present invention, if Rh is selected as the active metal, the prepared catalyst is suitable for the hydroformylation of various olefins, including olefins that are relatively difficult to react, such as isooctene. If other active metals are used, the prepared catalyst is generally more suitable for the hydroformylation of α-olefins, but the catalytic effect on olefins that are relatively difficult to react, such as isooctene, is relatively poor.

[0039] According to some embodiments of the present invention, the auxiliary metal includes at least one of Co, Zn, Cu, Mn, Bi, Ga, In, Sb, Sn, Fe, Al, Mg, Ce, Cs, Li, Na, and K.

[0040] Preferably, the promoter metal includes Co and / or Zn.

[0041] In the present invention, the promoter metal is selected from at least one of Co and Zn, which can make the catalyst have better catalytic performance compared with other types of promoter metals.

[0042] More preferably, the additive metal includes Co.

[0043] According to some embodiments of the present invention, the content of the active metal in the catalyst is 0.01 to 5 wt% based on the elemental content, for example, 0.01 wt%, 0.02 wt%, 0.04 wt%, 0.05 wt%, 0.08 wt%, 0.1 wt%, 0.15 wt%, 0.2 wt%, 0.3 wt%, 0.4 wt%, 0.5 wt%, 0.55 wt%, 0.6 wt%, 0.65 wt%, 0.7 wt%. , 0.75wt%, 0.78wt%, 0.8wt%, 0.82wt%, 0.84wt%, 0.88wt%, 0.9wt%, 1wt%, 1.05wt%, 1.1wt%, 1.2w t%, 1.3wt%, 1.4wt%, 1.5wt%, 1.7wt%, 2wt%, 2.5wt%, 3wt%, 3.3wt%, 3.8wt%, 4wt%, 4.5wt%, 5wt%, etc.

[0044] According to some embodiments of the present invention, the content of the active metal in the catalyst is 0.1 to 3 wt % based on the elemental content.

[0045] According to some embodiments of the present invention, the content of the active metal in the catalyst is 0.5-1.5 wt % based on the elemental content.

[0046] According to some embodiments of the present invention, the content of the promoter metal in the catalyst based on the elemental amount is 0.002-6 wt%, for example, 0.002 wt%, 0.004 wt%, 0.005 wt%, 0.008 wt%, 0.01 wt%, 0.02 wt%, 0.05 wt%, 0.06 wt%, 0.08 wt%, 0.1 wt%, 0.12 wt%, 0.15 wt%, 0.18 wt%, 0.2 wt%, 0.25 wt%, 0. .3wt%, 0.4wt%, 0.42wt%, 0.43wt%, 0.45wt%, 0.48wt%, 0.5wt%, 0.52wt%, 0.54wt%, 0.57wt%, 0.6wt%, 0. 7wt%, 0.8wt%, 0.9wt%, 1wt%, 1.2wt%, 1.5wt%, 1.9wt%, 2wt%, 2.5wt%, 3wt%, 3.5wt%, 4wt%, 5wt%, 6wt%, etc.

[0047] According to some embodiments of the present invention, the content of the promoter metal in the catalyst is 0.05 to 2 wt % calculated as a single substance.

[0048] According to some embodiments of the present invention, the content of the promoter metal in the catalyst is 0.2-0.7 wt % calculated as a single substance.

[0049] In a fourth aspect, the present invention provides a method for preparing the bimetallic heterogeneous catalyst supported by the nitrogen-modified carrier described in the third aspect, comprising: using a one-step constant temperature stirring impregnation method to load the active metal and the auxiliary metal on the nitrogen-modified carrier, and then undergoing a second calcination treatment to obtain the bimetallic heterogeneous catalyst supported by the nitrogen-modified carrier.

[0050] According to some embodiments of the present invention, the preparation method comprises the following steps:

[0051] S1. The nitrogen-modified carrier is added to the solvent and stirred to obtain a first dispersion;

[0052] S2. The active metal precursor and the additive metal precursor are added to the first dispersion to obtain a second dispersion; the reaction is stirred at a constant temperature of 25 to 100 ℃;

[0053] S3. After the reaction is completed, the reaction solution is cooled to room temperature and then solid-liquid separation is performed, and the obtained solid is subjected to a second calcination treatment to obtain the bimetallic heterogeneous catalyst supported by the nitrogen-modified support.

[0054] According to some embodiments of the present invention, the active metal precursor includes at least one of a chloride salt and a nitrate salt of the active metal.

[0055] Preferably, the active metal precursor includes at least one of a chloride salt and a nitrate salt of Rh.

[0056] Further preferably, the active metal precursor includes at least one of RhCl3, RhCl3·xH2O (such as RhCl3·3H2O), Rh(NO3)3, and Rh(NO3)3·2H2O.

[0057] According to some embodiments of the present invention, the auxiliary metal precursor includes at least one of nitrates, sulfates, and chlorides of the auxiliary metal.

[0058] According to some embodiments of the present invention, the auxiliary metal precursor includes at least one of nitrates, sulfates, and chlorides of Co and Zn.

[0059] According to some embodiments of the present invention, the auxiliary metal precursor includes at least one of Co(NO3)2, Co(NO3)2·6H2O, CoSO4, CoSO4·7H2O, CoCl2, CoCl2·6H2O, Zn(NO3)2, Zn(NO3)2·6H2O, ZnSO4, ZnSO4·7H2O, ZnCl2, and ZnCl2·xH2O.

[0060] According to some embodiments of the present invention, the concentration of the nitrogen-modified carrier in the first dispersion is 0.5 to 10 wt%, for example, 0.5 wt%, 0.6 wt%, 0.8 wt%, 0.9 wt%, 1 wt%, 1.1 wt%, 1.2 wt%, 1.5 wt%, 2 wt%, 2.5 wt%, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, 10 wt%, etc.

[0061] Preferably, the concentration of the nitrogen-modified carrier in the first dispersion is 0.8-5 wt %.

[0062] More preferably, the concentration of the nitrogen-modified carrier in the first dispersion is 1 to 3 wt %.

[0063] According to some embodiments of the present invention, the molar concentration of the active metal precursor in the second dispersion is 0.1 to 10 mmol / L, for example, it can be 0.1 mmol / L, 0.2 mmol / L, 0.3 mmol / L, 0.4 mmol / L, 0.5 mmol / L, 0.6 mmol / L, 0.7 mmol / L, 0.8 mmol / L, 0.9 mmol / L, 1.0 mmol / L, 1.1 mmol / L, 1.2 mmol / L, 1.5 mmol / L, 1.8 mmol / L, 2 mmol / L, 2.5 mmol / L, 3 mmol / L, 3.5 mmol / L, 4 mmol / L, 4.5 mmol / L, 5 mmol / L, 6 mmol / L, 7 mmol / L, 8 mmol / L, 9 mmol / L, 10 mmol / L, etc.

[0064] Preferably, the molar concentration of the active metal precursor in the second dispersion is 0.3 to 3 mmol / L.

[0065] More preferably, the molar concentration of the active metal precursor in the second dispersion is 0.5 to 1.5 mmol / L.

[0066] According to some embodiments of the present invention, the molar ratio of the active metal precursor calculated as a metal element to the auxiliary metal precursor calculated as a metal element is 1:(0.1-2), for example, it can be 1:0.1, 1:0.2, 1:0.3, 1:0.4, 1:0.5, 1:0.6, 1:0.7, 1:0.8, 1:0.9, 1:1, 1:1.1, 1:1.2, 1:1.3, 1:1.4, 1:1.5, 1:1.6, 1:1.7, 1:1.8, 1:1.9, 1:2, etc.

[0067] According to some embodiments of the present invention, the molar ratio of the active metal precursor calculated as a single metal to the auxiliary metal precursor calculated as a single metal is 1:(0.5-1.5).

[0068] According to some embodiments of the present invention, the stirring and mixing in step S1 is performed at room temperature for 5 to 15 minutes.

[0069] According to some embodiments of the present invention, the temperature of the stirring reaction in step S2 is 30-80°C.

[0070] According to some embodiments of the present invention, the stirring reaction time in step S2 is 5 to 20 hours, for example, it can be 5 hours, 6 hours, 7 hours, 8 hours, 9 hours, 10 hours, 11 hours, 12 hours, 13 hours, 14 hours, 15 hours, 16 hours, 17 hours, 18 hours, 19 hours, 20 hours, etc.

[0071] Preferably, the stirring reaction time in step S2 is 8 to 15 hours.

[0072] According to some embodiments of the present invention, in step S4, drying is performed before the second calcination treatment; preferably, the drying is vacuum drying.

[0073] According to some embodiments of the present invention, the second calcination treatment is performed in an inert atmosphere.

[0074] According to some embodiments of the present invention, the inert atmosphere includes at least one of nitrogen and an inert gas.

[0075] According to some embodiments of the present invention, the second calcination treatment comprises performing step-by-step continuous calcination in multiple temperature intervals within the range of room temperature to 900°C.

[0076] According to some embodiments of the present invention, the second calcination treatment includes: first heating the temperature to 200°C at a heating rate of 15-30°C / min and keeping the temperature constant for 1-2 hours; then heating the temperature to 300-900°C at a heating rate of 1-10°C / min and keeping the temperature constant for 3-10 hours.

[0077] According to some embodiments of the present invention, after the second calcination treatment is completed, the mixture is cooled to room temperature at a rate of 1 to 10° C. / min or a natural cooling rate.

[0078] According to some embodiments of the present invention, the solvent includes at least one of water, ethanol, methanol, n-hexane, and N,N-dimethylformamide.

[0079] In a fifth aspect, the present invention provides the use of the bimetallic heterogeneous catalyst supported by the nitrogen-modified support described in the third aspect or the bimetallic heterogeneous catalyst supported by the nitrogen-modified support prepared by the preparation method described in the fourth aspect in heterogeneous catalytic reactions, especially olefin hydroformylation reactions.

[0080] The beneficial effects of the present invention are at least:

[0081] The present invention uses a nitrogen-modified support to support bimetallic catalysts to prepare heterogeneous catalysts. The preparation method is simple and does not require the use of expensive phosphorus-containing organic ligands. The prepared nitrogen-modified support-supported bimetallic heterogeneous catalyst has better catalytic performance than existing bimetallic heterogeneous catalysts, has excellent catalytic performance for olefin hydroformylation, especially high-carbon olefin hydroformylation reactions, and has good stability. It has broad industrial application prospects in the field of heterogeneous catalysis. BRIEF DESCRIPTION OF THE DRAWINGS

[0082] Figure 1 These are the SEM-EDS energy spectra of the unmodified γ-Al2O3 and nitrogen-modified γ-Al2O3 in Preparation Example 1.

[0083] The SEM-EDS energy spectrum data were measured using a field emission scanning electron microscope (SEM, instrument model thermo scientific Apreo 2C). DETAILED DESCRIPTION

[0084] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments. It should be understood that the specific embodiments described herein are only used to illustrate this patent in detail and do not limit the scope of protection of the present invention in any way.

[0085] Unless otherwise defined, the technical terms used in the following examples have the same meanings as commonly understood by those skilled in the art to which this invention belongs. The reagents used in the following examples, unless otherwise specified, are all conventional biochemical reagents; the raw materials, instruments, and equipment used in the following examples, etc., are all commercially available or can be obtained by existing methods; the reagent amounts used, unless otherwise specified, are the amounts used in conventional experimental procedures; and the experimental methods described, unless otherwise specified, are all conventional methods.

[0086] Preparation Example 1

[0087] 0.3 g of alginic acid (Shanghai Aladdin Biochemical Technology Co., Ltd.), 0.24 g of ammonium carbonate and 1 g of γ-Al2O3 (particle size of 30-100 μm, specific surface area of ​​200-250 m 2 / g) was dispersed in 50 mL of deionized water and stirred at room temperature for 10 h. The solid and liquid phases were separated by filtration. The obtained solid was washed alternately with water and ethanol and dried in a vacuum drying oven at 60°C for 8 h. The obtained solid was pulverized and transferred to a tubular furnace for calcination to obtain a nitrogen-modified support.

[0088] The calcination procedure is as follows: after completely displacing the air in the tubular furnace with nitrogen, the temperature is raised to 800°C at a rate of 20°C / min in a nitrogen atmosphere, and after maintaining the temperature for 4 hours, the heating is turned off and the sample is naturally cooled to room temperature, and the calcination procedure is completed.

[0089] The SEM-EDS spectra of the unmodified γ-Al2O3 and the nitrogen-modified γ-Al2O3 prepared in this preparation example are shown in Figure 2. Figure 1 As shown in the figure, it can be seen that the nitrogen content in the nitrogen-modified γ-Al2O3 is significantly increased, indicating that the nitrogen modification of γ-Al2O3 has been successfully carried out.

[0090] Preparation Example 2

[0091] The preparation method of the nitrogen-modified carrier is similar to that of Preparation Example 1, except that the amount of alginic acid added is changed to 0.05 g, and the amount of ammonium carbonate added is changed to 0.04 g.

[0092] Preparation Example 3

[0093] The preparation method of the nitrogen-modified carrier is similar to that of Preparation Example 1, except that the amount of alginic acid added is changed to 0.1 g, and the amount of ammonium carbonate added is changed to 0.08 g.

[0094] Preparation Example 4

[0095] The preparation method of the nitrogen-modified carrier is similar to that of Preparation Example 1, except that the amount of alginic acid added is changed to 0.8 g, and the amount of ammonium carbonate added is changed to 0.64 g.

[0096] Preparation Example 5

[0097] The preparation method of the nitrogen-modified carrier is similar to that of Preparation Example 1, except that the amount of alginic acid added is changed to 1.0 g, and the amount of ammonium carbonate added is changed to 0.8 g.

[0098] Preparation Example 6

[0099] The preparation method of the nitrogen-modified carrier is similar to that of Preparation Example 1, except that the amount of ammonium carbonate added is changed to 0.03 g.

[0100] Preparation Example 7

[0101] The preparation method of the nitrogen-modified carrier was similar to that of Preparation Example 1, except that the amount of ammonium carbonate added was changed to 0.09 g.

[0102] Preparation Example 8

[0103] The preparation method of the nitrogen-modified carrier was similar to that of Preparation Example 1, except that the amount of ammonium carbonate added was changed to 0.15 g.

[0104] Preparation Example 9

[0105] The preparation method of the nitrogen-modified carrier is similar to that of Preparation Example 1, except that the amount of ammonium carbonate added is changed to 0.3 g.

[0106] Preparation Example 10

[0107] The preparation method of the nitrogen-modified carrier refers to Preparation Example 1, with the only difference being that ammonium carbonate is replaced by aqueous ammonia (25 wt %) with the same nitrogen content.

[0108] Preparation Example 11

[0109] The preparation method of the nitrogen-modified support refers to that of Preparation Example 1, except that the solid obtained after vacuum drying is not pulverized but directly transferred to a tube furnace for calcination.

[0110] Preparation Example 12

[0111] The preparation method of the nitrogen-modified support was similar to that of Preparation Example 1, except that the mixture was stirred at room temperature for 5 h.

[0112] Preparation Example 13

[0113] The preparation method of the nitrogen-modified carrier is similar to that of Preparation Example 1, except that the calcination temperature is 500°C.

[0114] Preparation Example 14

[0115] The preparation method of the nitrogen-modified carrier is similar to that of Preparation Example 1, except that the calcination temperature is 900°C.

[0116] Preparation Example 15

[0117] The preparation method of the nitrogen modified support is similar to that of Preparation Example 1, except that γ-Al2O3 is replaced by active Al2O3 (particle size of 30-100 μm, specific surface area of ​​167-192 m 2 / g).

[0118] Preparation Example 16

[0119] The preparation method of the nitrogen-modified support is similar to that of Preparation Example 1, except that γ-Al2O3 is replaced by silica (particle size of 30-100 μm, specific surface area of ​​200-250 m 2 / g).

[0120] Preparation Example 17

[0121] The preparation method of the nitrogen-modified support was similar to that of Preparation Example 1, except that γ-Al2O3 was replaced by SBA-15 (particle size of 30-100 μm, specific surface area of ​​200-250 m 2 / g).

[0122] Preparation Example 18

[0123] The preparation method of the nitrogen-modified support is similar to that of Preparation Example 1, except that γ-Al2O3 is replaced by carbon black (particle size of 30-100 μm, specific surface area of ​​200-250 m 2 / g).

[0124] Comparative Preparation Example 1

[0125] The preparation method of the nitrogen-modified carrier was similar to that of Preparation Example 1, except that alginic acid was replaced with an equal mass of natural polysaccharide uronic acid pectin (Shanghai Aladdin Biochemical Technology Co., Ltd.).

[0126] Comparative Preparation Example 2

[0127] The preparation method of the nitrogen-modified carrier is similar to that of Preparation Example 1, except that no alginic acid is added.

[0128] Examples 1-18

[0129] Take 1 g of the nitrogen-modified support prepared in Preparation Example 1-18 respectively, disperse it in 0.1 L of water, add 1 mL of a mixed aqueous solution of RhCl3 and Co(NO3)2 under stirring, so that the molar concentration of RhCl3 in the dispersion is 1 mmol / L and the molar concentration of Co(NO3)2 is 1 mmol / L. After constant temperature stirring at 50°C for 12 hours, the above mixture is filtered and separated, and the obtained solid is transferred to a vacuum drying oven and vacuum dried at 60°C for 8 hours to obtain a bimetallic loaded product.

[0130] The bimetallic-supported product was transferred to a tube furnace. Nitrogen was introduced to completely displace the air in the furnace. The temperature was then raised to 200°C at a rate of 20°C / min under a nitrogen atmosphere and held constant for 1 hour. The temperature was then raised to 500°C at a rate of 5°C / min and held constant for 5 hours. After the constant temperature period, the product was turned off and cooled naturally to room temperature to obtain a nitrogen-modified support-supported bimetallic heterogeneous catalyst.

[0131] Example 19

[0132] The preparation method of the catalyst is similar to that of Example 1, except that the molar concentration of RhCl3 in the dispersion is 1 mmol / L and the molar concentration of Co(NO3)2 is 0.5 mmol / L.

[0133] Example 20

[0134] The preparation method of the catalyst is similar to that of Example 1, except that the molar concentration of RhCl3 in the dispersion is 1 mmol / L and the molar concentration of Co(NO3)2 is 1.5 mmol / L.

[0135] Example 21

[0136] The preparation method of the catalyst is similar to that of Example 1, except that the molar concentration of RhCl3 in the dispersion is 1 mmol / L and the molar concentration of Co(NO3)2 is 2 mmol / L.

[0137] Example 22

[0138] The preparation method of the catalyst refers to Example 1, with the only difference being that a mixed aqueous solution of RhCl3 and Co(NO3)2 is added to the dispersion and then stirred at a constant temperature of 50°C for 6 hours.

[0139] Example 23

[0140] The preparation method of the catalyst refers to Example 1, with the only difference being that the bimetallic loaded product was heated to 200°C at a rate of 20°C / min under a nitrogen atmosphere, and then immediately heated to 500°C at a rate of 5°C / min and kept at that temperature for 5 hours without being kept constant for 1 hour.

[0141] Example 24

[0142] The preparation method of the catalyst is similar to that of Example 1, except that the bimetallic loaded product is directly heated to 500° C. at a rate of 20° C. / min under a nitrogen atmosphere and then kept at this temperature for 5 h.

[0143] Example 25

[0144] The preparation method of the catalyst is similar to that of Example 1, except that the Co(NO3)2 in the mixed aqueous solution is replaced by an equimolar amount (based on the metal element) of ZnCl2.

[0145] Example 26

[0146] The preparation method of the catalyst is similar to that of Example 1, except that the Co(NO3)2 in the mixed aqueous solution is replaced by an equimolar amount (based on the metal element) of CuCl2·2H2O.

[0147] Example 27

[0148] The preparation method of the catalyst is similar to that of Example 1, except that the RhCl3 in the mixed aqueous solution is replaced by an equimolar amount (based on the metal element) of IrCl3·6H2O.

[0149] Comparative Example 1

[0150] The preparation method of the catalyst is similar to that of Example 1, except that the nitrogen-modified support (nitrogen-modified γ-Al2O3) of Preparation Example 1 is replaced by γ-Al2O3 (particle size of 30 to 100 μm, specific surface area of ​​200 to 250 m2) that has not been nitrogen-modified. 2 / g).

[0151] Comparative Example 2

[0152] The preparation method of the catalyst refers to Example 1, except that the aqueous solution contains only RhCl3 and does not contain Co(NO3)2.

[0153] Comparative Example 3

[0154] The preparation method of the catalyst is similar to that of Example 1, except that the nitrogen-modified support of Preparation Example 1 is replaced by the nitrogen-modified support of Comparative Preparation Example 1.

[0155] Comparative Example 4

[0156] The preparation method of the catalyst is similar to that of Example 1, except that the nitrogen-modified support of Preparation Example 1 is replaced by the nitrogen-modified support of Comparative Preparation Example 2.

[0157] Comparative Example 5

[0158] The catalyst was prepared by referring to Example 27, except that the nitrogen-modified support (nitrogen-modified γ-Al2O3) of Preparation Example 1 was replaced by γ-Al2O3 (particle size of 30-100 μm, specific surface area of ​​200-250 m2) that was not nitrogen-modified. 2 / g).

[0159] Catalyst performance evaluation:

[0160] (1) Catalytic performance evaluation

[0161] Take 200 mg of each catalyst prepared in Example 1-26 or Comparative Example 1-4, mix them with 30 mL of isooctene and 10 mL of toluene, and transfer them into a high-pressure reactor. A CO / H2 mixed gas (the volume ratio of CO and H2 is 1:1) is introduced into the reactor. After replacing the air in the reactor, the pressure is increased to 6 MPa, stirring is started, and the reaction is carried out at a constant temperature of 100°C for 7 hours. The reaction results are shown in Table 1.

[0162] 200 mg of each catalyst prepared in Example 27 or Comparative Example 5 was taken, mixed with 3.5 mL of 1-octene and 10 mL of toluene, and then transferred to a high-pressure reactor. A CO / H2 mixed gas (the volume ratio of CO and H2 was 1:1) was introduced into the reactor. After replacing the air in the reactor, the pressure was increased to 10 MPa, stirring was started, and the reaction was carried out at a constant temperature of 150°C for 20 hours. The reaction results are shown in Table 1.

[0163] in:

[0164] (i) Conversion rate 烯烃 =(n 烷烃 +n 醛 +n 醇 ) / (n 烷烃 +n 醛 +n 醇 +n 剩余的烯烃 )×100%.

[0165] (ii) Selectivity (醛+醇) =(n 醛 +n 醇 ) / (n 烷烃 +n 醛 +n 醇 )×100%.

[0166] n in the formula 烷烃 、n 醛 、n 醇 、n 剩余的烯烃 They refer to the molar amounts of alkanes, aldehydes, alcohols, and unreacted olefins in the products, respectively.

[0167] (iii) Nitrogen content in the carrier: The nitrogen content was determined using a chemiluminescent nitrogen content analyzer (ANTEK 9000NT).

[0168] (iv) Active metal content and additive metal content: measured using an inductively coupled plasma spectrometer (iCAP 6300).

[0169] Table 1

[0170]

[0171]

[0172]

[0173] Note: Active metal content and additive metal content represent the content of active metal and additive metal in the catalyst respectively based on elemental content.

[0174] (2) Stability evaluation

[0175] The catalyst of Example 1 after catalytic performance evaluation was separated from the reaction mixture, washed, and dried, and the catalytic performance evaluation reaction in (1) was repeated. The results of 6 cycles are shown in Table 2.

[0176] Table 2

[0177] Number of cycles Conversion rate (%) (aldehyde + alcohol) selectivity (%) 1 92.0 97.3 2 91.8 97.3 3 91.5 97.1 4 91.6 97.2 5 91.2 97.0 6 90.5 96.9

[0178] As can be seen from Table 2, after the catalyst provided by the present invention is recycled for 6 times, the conversion rate and selectivity only decrease by 1.6% and 0.4% respectively, and the catalyst has good stability.

[0179] From the above results, it can be seen that the bimetallic heterogeneous catalyst supported by the nitrogen-modified support prepared in the present invention has excellent catalytic performance and stability in catalyzing the olefin hydroformylation reaction.

[0180] It should be noted that the embodiments described above are only used to explain the present invention and do not constitute any limitation of the present invention. The present invention has been described with reference to typical embodiments, but it should be understood that the words used therein are descriptive and explanatory words, rather than restrictive words. The present invention may be modified as specified within the scope of the claims of the present invention, and the present invention may be revised without departing from the scope and spirit of the present invention. Although the present invention described therein relates to specific methods, materials and embodiments, it does not mean that the present invention is limited to the specific examples disclosed therein. On the contrary, the present invention can be extended to all other methods and applications with the same function.

Claims

1. A method for preparing a nitrogen-modified carrier, characterized in that: include: The solid phase carrier is subjected to nitrogen modification treatment by using a nitrogen modifier comprising alginic acid and a weak acid ammonium salt to obtain the nitrogen-modified carrier; The mass ratio of alginic acid to weak acid ammonium salt is 1:(0.1-1.2), preferably 1:(0.5-1.0); The mass ratio of the alginic acid to the solid phase carrier is (0.05-1.5):1, preferably (0.2-1):

1.

2. The preparation method according to claim 1, characterized in that The weak acid ammonium salt includes at least one of (NH4)2CO3, NH4HCO3, and NH4OH, preferably (NH4)2CO3 and / or NH4OH, more preferably (NH4)2CO3; And / or, the solid support comprises at least one of oxides, carbon materials, molecular sieves, and MOFs; preferably, the solid support comprises Al2O3; more preferably, the solid support comprises γ-Al2O3; And / or, the particle size of the solid phase carrier is ≤100 μm, and the specific surface area is ≥200 m 2 / g; Preferably, the particle size of the solid phase carrier is 30-100 μm, and the specific surface area is 200-250 m 2 / g.

3. The preparation method according to claim 1 or 2, characterized in that include: Dispersing alginic acid, weak acid ammonium salt and solid phase carrier in water, stirring and mixing, separating solid phase and liquid phase, evaporating water from the solid phase, crushing, and performing a first calcination treatment to obtain the nitrogen-modified carrier; Preferably, The stirring and mixing temperature is 0 to 60° C., preferably 20 to 40° C.; the stirring and mixing time is 0.5 to 20 hours, preferably 6 to 15 hours, more preferably 8 to 12 hours; And / or, the heating rate of the first calcination treatment is 1-30°C / min, preferably 5-25°C / min; the temperature of the first calcination treatment is 400-1000°C, preferably 600-900°C; the time of the first calcination treatment is 0.5-10h, preferably 2-8h.

4. A nitrogen-modified carrier prepared by the preparation method according to any one of claims 1 to 3; Preferably, the nitrogen content in the nitrogen-modified carrier is 0.8 to 18.0 wt %, preferably 4.5 to 15.0 wt %.

5. A bimetallic heterogeneous catalyst supported on a nitrogen-modified carrier, characterized in that: The invention comprises a nitrogen-modified carrier prepared by the preparation method according to any one of claims 1 to 3 or the nitrogen-modified carrier according to claim 4, an active metal and an auxiliary metal; the active metal and the auxiliary metal are loaded on the nitrogen-modified carrier.

6. The nitrogen-modified support-supported bimetallic heterogeneous catalyst according to claim 5, characterized in that: The active metal includes at least one of Rh, Pb, Ir, Ru, and Au, preferably Rh; and / or, the auxiliary metal includes at least one of Co, Zn, Cu, Mn, Bi, Ga, In, Sb, Sn, Fe, Al, Mg, Ce, Cs, Li, Na, and K, preferably Co and / or Zn, more preferably Co; and / or the content of the active metal in the catalyst, calculated as a single substance, is 0.01 to 5 wt%, preferably 0.1 to 3 wt%, more preferably 0.5 to 1.5 wt%; And / or, the content of the promoter metal in the catalyst, calculated as a single substance, is 0.002 to 6 wt%, preferably 0.5 to 2 wt%, more preferably 0.2 to 0.7 wt%.

7. The method for preparing the nitrogen-modified support-supported bimetallic heterogeneous catalyst according to claim 5 or 6, characterized in that: include: The active metal and the auxiliary metal are loaded on the nitrogen-modified carrier by a one-step constant temperature stirring impregnation method, and then subjected to a second calcination treatment to obtain the bimetallic heterogeneous catalyst loaded on the nitrogen-modified carrier.

8. The preparation method according to claim 7, characterized in that The steps include: S1. The nitrogen-modified carrier is added to the solvent and stirred to obtain a first dispersion; S2. The active metal precursor and the additive metal precursor are added to the first dispersion to obtain a second dispersion; the reaction is stirred at a constant temperature of 25 to 100 ℃; S3. After the reaction is completed, the reaction solution is cooled to room temperature and then solid-liquid separation is performed, and the obtained solid is subjected to a second calcination treatment to obtain the bimetallic heterogeneous catalyst supported by the nitrogen-modified support.

9. The preparation method according to claim 8, characterized in that The active metal precursor includes at least one of a chloride salt and a nitrate salt of the active metal; preferably, the active metal precursor includes at least one of a chloride salt and a nitrate salt of Rh; further preferably, the active metal precursor includes RhCl3, RhCl 3· At least one of xH2O, Rh(NO3)3, and Rh(NO3)3·2H2O; And / or, the auxiliary metal precursor includes at least one of the nitrates, sulfates and chlorides of the auxiliary metal; preferably, the auxiliary metal precursor includes at least one of the nitrates, sulfates and chlorides of Co and Zn; further preferably, the auxiliary metal precursor includes at least one of Co(NO3)2, Co(NO3)2·6H2O, CoSO4, CoSO4·7H2O, CoCl2, CoCl2·6H2O, Zn(NO3)2, Zn(NO3)2·6H2O, ZnSO4, ZnSO4·7H2O, ZnCl2, and ZnCl2·xH2O.

10. The preparation method according to claim 8 or 9, characterized in that: The concentration of the nitrogen-modified carrier in the first dispersion is 0.5 to 10 wt %; and / or, the molar concentration of the active metal precursor in the second dispersion is 0.1 to 10 mmol / L; And / or, the molar ratio of the active metal precursor calculated as a single metal to the auxiliary metal precursor calculated as a single metal is 1:(0.1-2), preferably 1:(0.5-1.5).

11. The preparation method according to any one of claims 8 to 10, characterized in that: The stirring reaction temperature in step S2 is 30-80°C; And / or, the stirring reaction time in step S2 is 5 to 20 hours, preferably 8 to 15 hours; and / or, the second calcination treatment is performed in an inert atmosphere; And / or, the second calcination treatment comprises performing step-by-step continuous calcination in multiple temperature ranges from room temperature to 900° C.; preferably, the second calcination treatment comprises: first heating to 200° C. at a heating rate of 15-30° C. / min, holding the temperature for 1-2 hours; then heating to 300-900° C. at a heating rate of 1-10° C. / min, holding the temperature for 3-10 hours; and / or, after the second calcination treatment is completed, cooling to room temperature at a rate of 1 to 10° C. / min or a natural cooling rate; And / or, the solvent includes at least one of water, ethanol, methanol, n-hexane, and N,N-dimethylformamide.

12. Use of the nitrogen-modified support-supported bimetallic heterogeneous catalyst according to claim 5 or 6 or the nitrogen-modified support-supported bimetallic heterogeneous catalyst prepared by the preparation method according to any one of claims 7 to 11 in heterogeneous catalytic reactions, especially olefin hydroformylation reactions.

Images