Supported catalysts with metal / nitrogen carbon-metal phosphate interfaces, methods of making and use thereof

Abstract

Disclosed is a supported catalyst having a metal / nitrogen carbon-metal phosphate interface of general formula M1 / NC-M2(PO4) x or M1 / NC-HAP, wherein the active metal M1 is selected from one or more of the non-noble metals Ni, Cu, Fe and Co; NC represents a nitrogen carbon layer for modification of the support; M2 represents the metal in the support metal phosphate and is selected from one or more of Mn, Al, Pb, Ca, Mg, Zr, Ce and La; x has a value in the range of 0.1-3; and HAP represents hydroxyapatite. The catalyst of the present invention is prepared by loading the active metal on a modified support obtained by heat treatment after modification of the support metal phosphate or HAP by a nitrogen carbon layer, and then reduction in a hydrogen atmosphere after drying. The catalyst of the present invention can achieve a variety of catalytic hydrogenation reduction reactions under mild conditions.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of catalytic hydrogenation, in particular to a supported catalyst with a metal / nitrogen-carbon-metal phosphate interface and a preparation method and application thereof. BACKGROUND

[0002] Hydrogenation is one of the central themes in petrochemical, coal chemical, fine chemical and environmental industries. It is estimated that about 25% of organic chemical transformations include at least one hydrogenation step, so hydrogenation reaction is one of the most in-depth topics in catalysis. The key to hydrogenation reaction depends on the design and preparation of highly efficient and stable catalysts. Due to the advantages of easy separation and reuse and less environmental pollution, heterogeneous catalysts have broad application prospects.

[0003] Although noble metal-based catalysts show excellent catalytic activity in hydrogenation reactions, the high cost and limited availability of noble metals hinder their wide application, so it is necessary to develop inexpensive non-noble metal catalysts. However, although non-noble metal catalysts have significant cost advantage compared with noble metal catalysts, most of the non-noble metal catalysts can only achieve hydrogenation reaction under high temperature (usually higher than 150℃) and high pressure (usually higher than 3MPa). Therefore, it is urgent to develop and design highly efficient, stable and environmentally friendly non-noble metal catalysts for hydrogenation reactions to produce high-value chemicals.

[0004] As a carrier, phosphate is a solid acid catalyst carrier with good thermal stability, simple preparation process and low cost, and its surface has a large number of acid centers (P-OH). Phosphate carrier is beneficial to achieve contact between substrate and catalyst in catalytic organic molecular transformation, which can improve catalytic efficiency and activity, so it is widely used in hydrogenation, oxidation, condensation, ester exchange and other reaction types, and shows outstanding performance in liquid and gas phase reaction systems. However, non-noble metals often have poor dispersion or uneven size on phosphate carriers, which also leads to poor repeatability of catalyst large-scale preparation and significantly reduced catalytic efficiency.

[0005] In addition, as a carrier, carbon-based materials have become one of the most commonly used catalyst carrier materials due to their excellent chemical stability, adjustable high specific surface area, porosity and other properties. However, metal / carbon-based material catalysts usually have low activity in hydrogenation reaction and require harsh reaction conditions.

[0006] Therefore, there is a need in the art to develop a heterogeneous catalyst with high activity and high stability in the application of catalytic hydrogenation field, so as to realize the preparation of high-value chemicals under mild conditions. SUMMARY

[0007] The present application aims to solve the existing technical problems, based on the advantages of combining phosphate and carbon-based materials, introducing a nitrogen-carbon layer to modify the phosphate carrier and adjust the electronic structure of the loaded metal to construct a metal / nitrogen-carbon-metal phosphate interface, thereby providing a universal non-noble metal catalytic system with high catalytic activity and high stability in hydrogenation reactions, which can achieve efficient hydrogenation reactions under mild reaction conditions.

[0008] To this end, in one aspect, the present application provides a supported catalyst having a metal / nitrogen-carbon-metal phosphate interface, the supported catalyst being represented by the general formula M1 / NC-M2(PO4) x or M1 / NC-HAP, wherein M1 represents a loaded active metal and is selected from one or more of the non-noble metals nickel (Ni), copper (Cu), iron (Fe) and cobalt (Co); NC represents a nitrogen-carbon layer for modification; M2 represents a metal in the carrier metal phosphate and is selected from one or more of manganese (Mn), aluminum (Al), lead (Pb), calcium (Ca), magnesium (Mg), zirconium (Zr), cerium (Ce) and lanthanum (La); x represents the number of moles of phosphate based on 1 mole of carrier metal phosphate M2 and the value of x is in the range of 0.1-3; and HAP represents hydroxyapatite.

[0009] In preferred embodiments, the NC source for the nitrogen-carbon layer is an organic compound containing both carbon and nitrogen elements.

[0010] In preferred embodiments, in the carrier NC-M2(PO4) x or NC-HAP, the mass ratio of the nitrogen-carbon layer to the metal phosphate M2(PO4) x or hydroxyapatite HAP is in the range of 0.1-5:1.

[0011] In preferred embodiments, the NC source is selected from one or more of urea, melamine, glycine, lysine, alanine, 2-methylimidazole, dicyandiamide, dopamine and polyaniline.

[0012] In preferred embodiments, the loading amount of the active metal M1 is 1-10% by weight based on the total weight of the supported catalyst.

[0013] In another aspect, the present application provides a method for preparing the above-mentioned supported catalyst, the method comprising:

[0014] mixing an aqueous solution containing an NC source with an aqueous solution containing a metal phosphate M2(PO4) x or hydroxyapatite HAP under stirring, and drying to obtain a carrier precursor;

[0015] The obtained support precursor is subjected to a thermal treatment in an inert atmosphere or in an ammonia atmosphere at 400-800°C to obtain a nitrogen-carbon modified support NC-M2(PO4) x or NC-HAP;

[0016] The support NC-M2(PO4) x or NC-HAP is impregnated with a desired amount of an aqueous solution of a soluble salt of the active metal M1, and after drying, a catalyst precursor is obtained;

[0017] The obtained catalyst precursor is subjected to a reduction treatment in an inert atmosphere containing hydrogen or in a pure hydrogen atmosphere at 200-800°C to obtain the desired supported catalyst.

[0018] In a preferred embodiment, the metal phosphate M2(PO4) x is obtained by mixing an aqueous solution of a soluble salt of M2 with an aqueous solution of an ammonium salt containing phosphate ions under stirring, and the precipitate formed at basic pH is filtered, dried and calcined.

[0019] In a preferred embodiment, the hydroxyapatite HAP is natural or is obtained by mixing an aqueous solution of a soluble calcium salt with an aqueous solution of an ammonium salt containing phosphate ions under stirring, and the precipitate formed at basic pH is filtered, dried and calcined.

[0020] In a preferred embodiment, the drying is carried out at a temperature of 40-100°C for 1-12h; the impregnation is carried out for 4-24h; the reduction treatment is carried out for 1-8h.

[0021] In another aspect, the present application provides the use of the above-mentioned supported catalyst for catalysing a catalytic hydrogenation reduction reaction, in particular for the catalytic hydrogenation of furfural to furfuryl alcohol and / or tetrahydrofurfuryl alcohol, of benzaldehyde to benzyl alcohol or of nitrobenzene to aniline.

[0022] In a preferred embodiment, the catalytic hydrogenation reduction reaction is carried out at a H2 pressure of 0.1-2MPa and at a temperature of 30-140°C.

[0023] In a preferred embodiment, the reaction of catalytic hydrogenation of furfural to furfuryl alcohol and / or tetrahydrofurfuryl alcohol is carried out at a temperature of 40-120°C; the reaction of catalytic hydrogenation of benzaldehyde to benzyl alcohol is carried out at a temperature of 50-120°C; the reaction of catalytic hydrogenation of nitrobenzene to aniline is carried out at a temperature of 60-140°C.

[0024] The present application obtains a nitrogen-carbon modified phosphate carrier by modifying a metal phosphate or hydroxyapatite as a carrier with a nitrogen-carbon layer, and then loading a non-noble metal as an active metal and undergoing reduction, to obtain a new heterogeneous catalyst with a metal / nitrogen-carbon-metal phosphate interface, which has high activity and high stability.

[0025] The catalyst of the present application can be simply prepared by heat treating the modified carrier after heat treating the nitrogen-carbon modified phosphate through calcination after impregnation, and then loading the active metal through impregnation and drying, and then reducing in a hydrogen atmosphere.

[0026] After the modification of the nitrogen-carbon layer on the phosphate or hydroxyapatite carrier, the specific surface area of the catalyst is greatly increased, the defect sites for anchoring the active metal are increased, and the binding capacity with the active metal is enhanced, thereby overcoming the problem of rapid deactivation of the catalyst caused by rapid aggregation and elution of metal species during catalysis, greatly improving the stability of the catalyst. In addition, the interface formed between the nitrogen-carbon layer and the phosphate causes effects such as electron transfer, metal modification, and hydrogen overflow, thereby being able to adjust the electronic structure of the active metal, improve the adsorption of reaction intermediates, greatly enhance the catalytic activity of the non-noble metal, and enable various catalytic hydrogenation reduction reactions to be realized under mild conditions. In particular, the supported catalyst of the present application can catalyze the hydrogenation of furfural to prepare furfuryl alcohol and tetrahydrofurfuryl alcohol, the hydrogenation of benzaldehyde to prepare benzyl alcohol, and the hydrogenation of nitrobenzene to prepare aniline under very mild conditions. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 X-ray diffraction (XRD) patterns of hydroxyapatite (HAP), nitrogen-carbon modified hydroxyapatite (NC-HAP), and catalyst 10Ni / NC-HAP prepared according to the present application are shown;

[0028] Figure 2 High-angle annular dark-field scanning transmission electron microscopy (HADDF-STEM) patterns of catalyst 10Ni / NC-HAP prepared according to the present application are shown.

[0029] Figure 3 To Figure 2 Element mapping (EDS) patterns corresponding to the photographed area, mainly including EDS patterns of species elements Ni, Ca, C, N, O, and P on the surface of the carrier. DETAILED DESCRIPTION

[0030] The present inventors have recognized that (1) there are still considerable difficulties in using existing non-noble metal catalysts to prepare high-value chemicals by hydrogenation reactions, for example, such catalysts have low catalytic efficiency, and harsh reaction temperatures or hydrogen pressures are required to obtain high product yield; (2) the product distribution and hydrogenation rate of hydrogenation reactions are usually dependent on the affinity of reactants to metals, and the adsorption mode of adsorbate on specific sites of the catalyst; (3) phosphates are beneficial to achieving contact between substrates and catalysts during catalytic organic molecular conversion, improving catalytic efficiency and activity, while carbon-based materials are rich in defect / sites anchoring metals on the surface; (4) doping nitrogen atoms in carbon materials can produce more abundant defects and active sites, forming strong interactions between metals and supports, further anchoring metals and enhancing the stability of the catalyst. In view of this, after extensive and in-depth research, the present inventors have unexpectedly found that by forming a new support through interface modification combining the two, the catalytic activity and stability of non-noble metals can be greatly enhanced.

[0031] Based on any and the above findings, the present application provides a supported catalyst having a metal / nitrogen carbon-metal phosphate interface, which can be represented by the general formula M1 / NC-M2(PO4) x or M1 / NC-HAP.

[0032] In the above general formula, M1 represents a supported active metal and is selected from one or more of the non-noble metals nickel (Ni), copper (Cu), iron (Fe) and cobalt (Co). Preferably, the loading of the active metal M1 is 1-10 wt.%, based on the total weight of the supported catalyst. The present inventors have found that when the loading of the active metal is within the above range, a relatively balanced high activity and high stability can be obtained while also having good economics.

[0033] In the above general formula, M2 represents the support phosphate metal, i.e. the metal in M2(PO4) x , and is selected from one or more of manganese (Mn), aluminum (Al), lead (Pb), calcium (Ca), magnesium (Mg), zirconium (Zr), cerium (Ce) and lanthanum (La); and x represents the number of moles of phosphate based on 1 mole of the support phosphate metal M2, i.e. in the phosphate M2(PO4) x , the number of moles of phosphate (PO4 3- ) corresponding to 1 mol of the metal M2 (ion), and the value of x is in the range of 0.1-3.

[0034] In the above general formula, HAP represents hydroxyapatite, which is typically represented by the chemical formula Ca 10 (PO4)6(OH)2.

[0035] In the above general formula, NC represents a nitrogen-carbon layer for modification. The present inventors have found that by introducing a nitrogen-carbon layer to modify the phosphate support or HAP support, the interfacial interaction between the supported non-noble metal and the modified NC-phosphate support can be significantly enhanced, the activation ability for the substrate and hydrogen in the hydrogenation reaction can be improved, and thus the hydrogenation reaction can occur under milder conditions. Preferably, the NC source for the nitrogen-carbon layer of the catalyst of the present application is an organic compound containing both carbon and nitrogen elements, but it should be understood that a C source and a N source can also be used separately to provide the desired nitrogen-carbon layer in the present application. Further preferably, the NC source that can be used in the present application includes, but is not limited to, urea, melamine, glycine, lysine, alanine, 2-methylimidazole, dicyandiamide, dopamine, polyaniline, etc., or a mixture thereof.

[0036] In the support NC-M2(PO4) x or NC-HAP of the catalyst of the present application, preferably, the mass ratio of the nitrogen-carbon layer to the metal phosphate M2(PO4) x or hydroxyapatite HAP is in the range of 0.1-5:1. The present inventors have found that when the mass ratio of the nitrogen-carbon layer to the metal phosphate M2(PO4) x or hydroxyapatite HAP is in the above range, the obtained support has more abundant anchoring sites, enabling stronger interaction (SMSIs) between the active non-noble metal and the support, further overcoming the problem of rapid deactivation of the catalyst caused by rapid aggregation and dissolution of the metal species during the catalytic process, thereby more effectively stabilizing the state of the metal species and significantly improving the stability of the obtained catalyst; at the same time, the interface formed between the nitrogen-carbon layer and the phosphate causes effects such as electron transfer, metal modification, and hydrogen overflow, thereby being able to adjust the electronic structure of the active metal and precisely control the electronic state of the metal (usually nanosized) particles, greatly enhancing the catalytic activity of the non-noble metal.

[0037] The supported catalyst of the present application can be prepared by the following method: first, mixing an aqueous solution containing an NC source with an aqueous solution containing a metal phosphate M2(PO4) x or hydroxyapatite HAP under stirring and then drying to obtain a support precursor; then, heat-treating the obtained support precursor in an inert atmosphere or an ammonia atmosphere at 400-800°C to obtain a nitrogen-carbon modified support NC-M2(PO4) x or NC-HAP; next, impregnating the support NC-M2(PO4) x or NC-HAP with a desired amount of an aqueous solution of a soluble salt of the active metal M1, and drying to obtain a catalyst precursor; finally, reducing the obtained catalyst precursor in a hydrogen-containing inert atmosphere or a pure hydrogen atmosphere at 200-800°C to obtain the desired supported catalyst.

[0038] In the present application, the metal phosphate M2(P04) used x There is no particular limitation, and it can be a phosphate salt purchased directly or synthesized by a synthetic method. For example, the metal phosphate M2(P04) used x It can be obtained by mixing an aqueous solution of a soluble salt of M2 with an aqueous solution of an ammonium salt containing phosphate ions under stirring, filtering, drying and calcining the precipitate produced at alkaline pH.

[0039] In the present application, the HAP used can be natural or synthetic. For example, the HAP used can be synthesized by mixing an aqueous solution of a soluble calcium salt with an aqueous solution of an ammonium salt containing phosphate ions under stirring, filtering, drying and calcining the precipitate produced at alkaline pH (for example, pH is about 11, and if necessary, it can be adjusted by adding an alkaline reagent such as ammonia water).

[0040] In the present application, the modification of the metal phosphate or HAP by the nitrogen-carbon layer can be carried out by means known in the art. For example, when lysine is used as the NC source, an aqueous solution of lysine based on the required mass after conversion is added dropwise to an aqueous solution of the phosphate salt of the required mass by means of a constant pressure dropping funnel under continuous magnetic stirring (the rotation speed can be set to 900 r / min, for example) using a water bath heating device (for example, the water bath temperature can be set to 50°C, for example), after which stirring and drying are carried out.

[0041] In the present application, preferably, in order to obtain the support precursor, drying can be carried out at a temperature of 40-100°C for 1-12 h, for example.

[0042] In the present application, the inert atmosphere used can generally be a nitrogen atmosphere or an argon atmosphere. In addition, the heat treatment mentioned in the present application in an inert atmosphere or an ammonia atmosphere means heat treatment in an inert atmosphere free of oxygen, such as N2atmosphere, or in an ammonia atmosphere, for example, heating to 400°C under oxygen-free conditions for 2-8 h, such as 2 h. The support obtained by the above method not only plays a role in dispersing and stabilizing the active metal (usually nanosized) particles, but also interacts with the active metal particles, and this interaction often leads to phenomena such as interfacial charge transfer, metal structure change, molecular adsorption modulation, etc., thereby affecting the activity, selectivity and stability of the catalyst.

[0043] In the present application, the operation of impregnating the support with an aqueous solution of a soluble salt of the active metal M1is known in the art. Preferably, the impregnation of the support with an aqueous solution of a soluble salt of the active metal M1may be carried out for 4 to 24 h. The soluble salt here can refer to a nitrate, acetate or chloride salt of the metal M1, etc. Such a soluble salt can form a corresponding solution by dissolving in a commonly used solvent such as water, acetone, ethanol or a mixed solvent thereof. In the present application, for example, the concentration of the aqueous solution of the soluble salt of the metal M1formed can range from 2 to 25 mmol / L, which can be obtained by dissolving 0.8 mmol to 10 mmol of the metal soluble salt in 400 mL of water to obtain an aqueous solution of the desired concentration, for example.

[0044] In the present application, the inert atmosphere containing hydrogen gas can be, for example, a nitrogen atmosphere or an argon atmosphere containing 10% by volume of H2. Preferably, the reduction treatment of the catalyst precursor can be carried out for 1 to 8 h.

[0045] The supported catalyst of the present application can be used for various catalytic hydrogenation (reduction) reactions. For example, such catalytic hydrogenation reactions can refer to the catalytic hydrogenation of furfural to prepare furfuryl alcohol and / or tetrahydrofurfuryl alcohol, the catalytic hydrogenation of benzaldehyde to prepare benzyl alcohol or the catalytic hydrogenation of nitrobenzene to prepare aniline, etc. Preferably, the catalytic hydrogenation reduction reaction is carried out at a H2pressure of 0.1 to 2 MPa and a temperature of 30 to 140°C. Further, for example, the reaction of the catalytic hydrogenation of furfural to prepare furfuryl alcohol and / or tetrahydrofurfuryl alcohol can be preferably carried out at a temperature of 40 to 70°C, the reaction of the catalytic hydrogenation of benzaldehyde to prepare benzyl alcohol can be preferably carried out at a temperature of 50 to 100°C, and the reaction of the catalytic hydrogenation of nitrobenzene to prepare aniline can be preferably carried out at a temperature of 60 to 140°C.

[0046] The present application will be described in detail below in the form of non-limiting examples including catalyst preparation examples and application examples. These examples are merely non-limiting examples for illustrating the specific implementation and realization process of the present application, and are not intended to limit the scope of the present application.

[0047] In the following examples, unless specifically specified otherwise, the equipment, reagents and raw materials used are commercially available and can be used directly after purchase without further treatment. Also, unless specifically specified otherwise, the reaction processes and treatment methods involved are known in the art or are conventional operations.

[0048] Preparation Example 1: Preparation of catalyst 10Ni / NC-HAP

[0049] Into a 500 mL round bottom flask, 300 mL of 0.5 mol / L Ca(NO3)2·4H2O (National Pharmaceutical Group Chemical Reagent Co., Ltd.) and 40 mL of 0.5 mol / L (NH4)2HPO4 solution (National Pharmaceutical Group Chemical Reagent Co., Ltd.) were added, followed by heating and stirring (speed of 900 r / min) in a constant temperature oil bath set at 45°C, adjusting the pH to 11 with ammonia water (National Pharmaceutical Group Chemical Reagent Co., Ltd.), and magnetic stirring for 2 h. After vacuum filtration, distilled water washing, and drying in a 100°C oven (Anhui Kepu Instruments Co., Ltd.), a white solid powder was obtained, which was then calcined at a high temperature of 600°C in a sealed tube furnace to obtain crystalline HAP. The obtained HAP was subjected to X-ray diffraction (XRD) analysis, and the results are shown in Figure 1 .

[0050] In a 500 mL round bottom flask, 10 g of HAP was poured into 200 mL of water to form a suspension, which was then transferred to a stirring oil bath set at 45°C with a magnetic stirring speed of 900 r / min, and then a water solution containing 5 g of lysine (National Pharmaceutical Group Chemical Reagent Co., Ltd.) was added dropwise through a dropping funnel (dropping speed of one drop per second). After 24 h of continuous stirring, rotary evaporation and drying, the NC-modified HAP carrier precursor was obtained. Then, the obtained carrier precursor was heat-treated in a sealed tube furnace at 400°C in a nitrogen atmosphere to obtain the catalyst carrier NC-HAP. The obtained carrier NC-HAP was subjected to X-ray diffraction (XRD) analysis, and the results are shown in Figure 1 .

[0051] In a flask placed and fixed in an oil bath stirring device (temperature set at 45°C, stirring speed set at 700 r / min), 5.0 g of the NC-HAP carrier precursor was immersed in 400 mL of an aqueous solution containing 2.7 g of nickel nitrate (National Pharmaceutical Group Chemical Reagent Co., Ltd.) and stirred for 18 h to achieve full impregnation. Then, rotary evaporation was performed, and the obtained material was dried in a 100°C oven for 10 h to obtain the catalyst precursor.

[0052] Finally, in a sealed tube furnace, a mixture of nitrogen and hydrogen gas (10% H2 / N2, Nanjing Special Gas Co., Ltd.) was introduced, and the temperature was programmed to rise to 600°C at a rate of 1°C / min and reduced for 3 h to obtain the nitrogen-carbon modified supported phosphate catalyst.

[0053] Through inductively coupled plasma emission spectrometry (ICP) testing, it was determined that the loading of metal Ni was 10% by weight (relative to the weight of the entire catalyst), and accordingly the catalyst was calculated as 10Ni / NC-HAP. The obtained catalyst 10Ni / NC-HAP was subjected to X-ray diffraction (XRD) analysis, and the results are shown in Figure 1 .

[0054] By Figure 1 It can be seen that the lattice diffraction peaks of Ni and HAP appear in the XRD spectrum, indicating that the Ni / NC-HAP catalyst still contains metal nickel and hydroxyapatite components. By comparing the lattice diffraction peaks of pure HAP, it can be found that the diffraction peak intensity of hydroxyapatite on it is partially covered, indicating that the nitrogen-carbon layer modifies the hydroxyapatite.

[0055] Figure 2 And Figure 3 The electron microscope spectrum and element mapping (EDS) of the above prepared catalyst 10Ni / NC-HAP are shown (mainly including the EDS of the species elements Ni, Ca, C, N, O and P on the surface of the carrier). By Figure 2 And Figure 3 It can be seen that the elements Ni, Ca, C, N, O and P in the obtained catalyst are uniformly dispersed, and the nitrogen-carbon component modifies the hydroxyapatite well.

[0056] Therefore, it is proved that in the present application, after the metal Ni precursor is impregnated with the carrier NC-HAP, the multi-component heteroatom carrier NC-HAP is fully anchored to the Ni species to make it uniformly dispersed after oxygen-free heat treatment; then, the metal electronic structure is reasonably adjusted by further reduction treatment with hydrogen H2, forming a strong metal-carrier interaction, which leads to the obtained catalyst to exhibit better catalytic activity and stability.

[0057] Preparation Example 2: Preparation of catalyst 10Cu / NC-HAP

[0058] First, the same procedure as in Preparation Example 1 was used to prepare the carrier NC-HAP, except that the NC source was changed to 5g of melamine and the heat treatment atmosphere of the carrier precursor was changed from nitrogen atmosphere to ammonia atmosphere.

[0059] Next, in substantially the same procedure as in the above Preparation Example 1, 5.0g of the NC-HAP carrier precursor was immersed in 400mL of an aqueous solution containing 2.1g of copper nitrate (National Pharmaceutical Group Chemical Reagent Co., Ltd.) in a flask placed and fixed in an oil bath stirring device (temperature set to 45℃, stirring speed set to 700r / min) for 24h to achieve full impregnation. Then, rotary evaporation was performed, and the obtained material was dried in an oven at 100℃ for 10h to obtain a catalyst precursor.

[0060] Finally, in a sealed tube furnace, a mixed gas of nitrogen and hydrogen (10% H2 / N2, Nanjing Special Gas Co., Ltd.) was introduced, and the temperature was programmed to increase to 300℃ at a heating rate of 1℃ / min for 2h reduction, thereby obtaining a catalyst with a copper loading of 10%, which is denoted as 10Cu / NC-HAP.

[0061] Preparation Example 3-20

[0062] With the same procedure as described above in Preparation Example 1 or Preparation Example 2, the following catalysts were prepared by appropriately changing the NC support and its amount, the active metal species and its loading, and the different phosphate or HAP: 2Cu / NC-HAP, 5Cu / NC-HAP, 5Ni / NC-HAP, 2Co / NC-HAP, 5Co / NC-HAP, 1 Ni / NC-HAP, 10Fe / NC-HAP, 10Co / NC-HAP, 10Ni / NC-MnPO4, 10Ni / NC-AlPO4, 10Cu / NC-MnPO4, 10Cu / NC-ZrPO4, 10Fe / NC-MnPO4, 10Fe / NC-CePO4, 10Co / NC-MnPO4, 10Co / NC-ZrPO4, 10Cu / NC-CaPO4, and 1 Co / NC-MnPO4.

[0063] Preparation Comparative Examples 1-16

[0064] With the same procedure as described above in Preparation Example 1, the following supported catalysts for comparison were prepared by loading the metals Ni and Co with a loading of 10% on the supports activated carbon (C), nitrogen-carbon doped support (NC), MgO, CeO2, ZrO2, TiO2, Al2O3, and metal phosphates and hydroxyapatite HAP: 10Ni / C, 10Ni / NC, 10Ni / MgO, 10Ni / CeO2, 10Ni / MnPO4, 10Ni / CePO4, 10Ni / ZrPO4, 10Ni / HAP, 10Co / C, 10Co / NC, 10Co / ZrO2, 10Co / TiO2, 10Co / AlPO4, 10Co / MnPO4, 10Co / ZrPO4, and 10Co / HAP.

[0065] Application Example 1 : Application for catalyzing the hydrogenation of furfural to furfuryl alcohol and / or tetrahydrofurfuryl alcohol

[0066]

[0067] A 1 L autoclave with stirring and heating device was charged with 800 mL of 3 wt% concentration of furfural aqueous solution (Shanghai Aldrin Biochemical Science and Technology Co., Ltd.). Then, 2 g of catalyst 10Ni / NC-HAP prepared in Preparation Example 1 was put into the autoclave. The reaction environment was purged with H2 and then with air 6 times to remove the residual air. After being stabilized by charging 1.5 MPa of hydrogen, the reaction was carried out under magnetic stirring and heating by oil bath to 70°C for 4 h. After the reaction, cyclohexane (Shanghai Aldrin Biochemical Science and Technology Co., Ltd.) was added to the reaction solution and centrifuged (10000 r / min), and the supernatant was taken for qualitative and quantitative analysis of the product by gas chromatography.

[0068] The gas chromatography conditions were as follows: GC1690 gas chromatograph, FID detector, capillary column (HP-INNOWax, 30 m x 0.250 mm x 0.25 μm), and programmed temperature was adopted, the initial column temperature was 100°C, and the temperature was increased to 200°C at a rate of 10°C / min and maintained for 3 min. The carrier gas was 99.99% high-purity N2, and the flow rate was 1 mL / min; the auxiliary gas was air. The reaction conditions and results (conversion rate of reactants and selectivity of products) are shown in Table 1.

[0069] Application Example 2-8: Application for catalyzing the hydrogenation of furfural to prepare furfuryl alcohol and / or tetrahydrofurfuryl alcohol

[0070] In addition to using the catalysts and reaction conditions listed in Table 1, the catalytic hydrogenation reaction of furfural (3 wt% concentration of aqueous solution) was carried out in the same procedure as described in Application Example 1 (the hydrogen pressure was maintained at 1.5 MPa). The other reaction conditions and results (conversion rate of reactants and selectivity of products) are shown in Table 1.

[0071] Table 1

[0072]

[0073] As can be seen from Table 1, the catalysts used in the application all have excellent catalytic hydrogenation activity. In addition, when the supported metal is Ni and Co, it has higher hydrogenation activity than Fe and Cu, and can catalyze the hydrogenation of furfural to tetrahydrofurfuryl alcohol. In addition, the difference in reaction time and metal loading also has a significant effect on the catalytic activity, for example, for Ni / NC-HAP, when the metal loading is reduced, the main product is furfuryl alcohol.

[0074] Application Example 9-16: Application for catalyzing the hydrogenation of furfural to prepare furfuryl alcohol and / or tetrahydrofurfuryl alcohol

[0075] In addition to using the catalysts and reaction conditions listed in Table 2, catalytic hydrogenation of furfural (3% by weight aqueous solution) was carried out in the same procedure as described in Application Example 1. Other reaction conditions and results (reactant conversion and product selectivity) are shown in Table 2.

[0076] Table 2

[0077]

[0078] According to the results in Table 2, in addition to the similar conclusions as described above for Table 1, it can be seen that the catalytic activity of Ni and Co metals supported on the NC modified support of the present application is higher than that of Cu and Fe, and they have excellent hydrogenation activity even at lower reaction temperatures.

[0079] Application Examples 17-32: Application for catalyzing hydrogenation of benzaldehyde to benzyl alcohol

[0080]

[0081] In a 1 L autoclave with stirring and heating devices, 800 mL of 3% by weight benzaldehyde aqueous solution (Shanghai Aladdin Bio-Chem Technology Co., Ltd.) was added. Then, 2 g of the catalyst shown in Table 3 was put into the autoclave. The reaction environment was purged with H2 and then discharged 6 times to remove the remaining air. Finally, the reaction was carried out under the hydrogen pressure and reaction conditions shown in Table 3. After the reaction, cyclohexane (Shanghai Aladdin Bio-Chem Technology Co., Ltd.) was added to the reaction solution and centrifuged (10000 r / min), and the supernatant was taken for qualitative and quantitative analysis of the products by gas chromatography.

[0082] The gas chromatography conditions were as follows: GC1690 gas chromatograph, FID detector, capillary column (HP-INNOWax, 30 m x 0.250 mm x 0.25 μm), programmed temperature rise, initial column temperature 100°C, temperature rise rate 10°C / min to 200°C for 3 min. The carrier gas was 99.99% high-purity N2, and the flow rate was 1 mL / min; the auxiliary gas was air.

[0083] Other reaction conditions and results (reactant conversion and product selectivity) are shown in Table 3.

[0084] Table 3

[0085]

[0086] Application Examples 33-48: Application for catalyzing hydrogenation of nitrobenzene to aniline

[0087]

[0088] A 1 L autoclave with stirring and heating device was charged with 800 mL of 3 wt% concentration of nitrobenzene aqueous solution (Shanghai Aldrin Biochemical Science and Technology Co., Ltd.). Then, 2 g of the catalyst shown in Table 4 was put into the autoclave. The reaction environment was purged with H2 and then with air 6 times to remove the residual air. Finally, the reaction was carried out under the hydrogen pressure and reaction conditions shown in Table 4. After the reaction, cyclohexane (Shanghai Aldrin Biochemical Science and Technology Co., Ltd.) was added to the reaction solution and centrifuged (10000 r / min), and the supernatant was taken for qualitative and quantitative analysis of the product by gas chromatography.

[0089] The gas chromatography conditions were as follows: GC1690 gas chromatograph, FID detector, capillary chromatographic column (HP-INNOWax, 30 m x 0.250 mm x 0.25 μm), and programmed temperature was adopted, the initial column temperature was 100°C, and the temperature was increased to 200°C at a rate of 10°C / min and maintained for 3 min. The carrier gas was 99.99% high-purity N2, and the flow rate was 1 mL / min; the auxiliary gas was air.

[0090] Other reaction conditions and results (reactant conversion rate and product selectivity) are shown in Table 4.

[0091] Table 4

[0092]

[0093] Comparative Examples 1-16:

[0094] In addition to using the comparative catalysts listed in Table 5 and reaction conditions, the catalytic hydrogenation reaction of furfural (3 wt% concentration of aqueous solution) was carried out in the same procedure as described in Application Example 1 (hydrogen pressure was maintained at 1.5 MPa). Other reaction conditions and results (reactant conversion rate and product selectivity) are shown in Table 5.

[0095] Table 5

[0096]

[0097] From the results of the above Tables 1 to 4, it can be seen that the supported catalysts with metal / nitrogen-carbon-metal phosphate interface according to the present application can realize various catalytic hydrogenation reactions such as the hydrogenation of furfural to furfuryl alcohol and tetrahydrofurfuryl alcohol, the hydrogenation of benzaldehyde to benzyl alcohol, and the hydrogenation of nitrobenzene to aniline under very mild reaction conditions (hydrogen pressure of 0.1 to 2 MPa, temperature of 30 to 140 °C, and reaction time of 1 to 8 h). In contrast, from the results of the above Table 5, it can be seen that even under the same or substantially same reaction conditions, the conversion of the reactant furfural and the yield of the corresponding product furfuryl alcohol and / or tetrahydrofurfuryl alcohol are significantly lower when the comparative catalysts use Ni and Co as the active metal and have a loading of 10% which is the highest, and under the reaction conditions of higher reaction temperature of 70 to 120 °C and longer reaction time of 4 to 8 h. This indicates that the supported catalysts with metal / nitrogen-carbon-metal phosphate interface according to the present application have higher catalytic activity and stability in catalytic hydrogenation reactions, and are much superior to the conventional catalysts in performance.

[0098] In addition, the supported catalysts with metal / nitrogen-carbon-metal phosphate interface according to the present application can be used to prepare high-value chemicals such as furfuryl alcohol, tetrahydrofurfuryl alcohol, or benzyl alcohol, etc. by catalytic hydrogenation under simple process and low equipment energy consumption, and the products are easy to separate from the catalyst, which is suitable for industrial production and has very wide application prospects.

[0099] The preferred embodiments of the present application have been described above with the aid of drawing. Obviously, the present application is not limited to these preferred embodiments, and any modifications, equivalent replacements, and improvements made without departing from the spirit and principles of the present application shall fall within the protection scope of the present application.

Claims

1. A supported catalyst having a metal / nitrogen-carbon-metal phosphate interface for catalytic hydrogenation reduction reactions, said supported catalyst being of the general formula M1 / NC-M2(PO4). x Alternatively, it may be represented as M1 / NC-HAP, where M1 represents the supported active metal selected from one or more of the non-noble metals Ni, Cu, Fe, and Co; NC represents the nitrogen-carbon layer used for modification; M2 represents the metal in the support metal phosphate selected from one or more of Mn, Al, Pb, Ca, Mg, Zr, Ce, and La; x represents the number of moles of phosphate ions based on 1 mole of support phosphate metal M2 and the value of x is in the range of 0.1 to 3; and HAP represents hydroxyapatite.

2. The supported catalyst according to claim 1, characterized in that, The NC source used for the nitrogen-carbon layer is an organic compound containing both carbon and nitrogen elements.

3. The supported catalyst according to claim 1, characterized in that, In the carrier NC-M2(PO4) x Or in NC-HAP, the nitrogen-carbon layer is combined with the metal phosphate M2(PO4). x The mass ratio of hydroxyapatite (HAP) to hydroxyapatite (HAP) is in the range of 0.1 to 5:

1.

4. The supported catalyst according to claim 2, characterized in that, The NC source is selected from one or more of urea, melamine, glycine, lysine, alanine, 2-methylimidazole, dicyandiamide, dopamine, and polyaniline.

5. The supported catalyst according to claim 1, characterized in that, Based on the total weight of the supported catalyst, the loading of active metal M1 is 1-10 by weight.

6. A method for preparing a supported catalyst according to any one of claims 1 to 5, the method comprising: An aqueous solution containing an NC source was reacted with a metal phosphate M2(PO4). x Alternatively, an aqueous solution of hydroxyapatite (HAP) is mixed under stirring and then dried to obtain a carrier precursor; The obtained support precursor was heat-treated in an inert atmosphere or an ammonia atmosphere at 400-800℃ to obtain the nitrogen-carbon modified support NC-M2(PO4). x Or NC-HAP; The carrier NC-M2(PO4) is impregnated with a soluble salt solution of the active metal M1 in the required amount. x Alternatively, NC-HAP, after drying, yields the catalyst precursor; The obtained catalyst precursor is reduced in an inert atmosphere containing hydrogen or in a pure hydrogen atmosphere at 200-800℃ to obtain the desired supported catalyst.

7. The method according to claim 6, characterized in that, The metal phosphate M2(PO4) x It is obtained by mixing a soluble salt solution of M2 with an ammonium salt solution containing phosphate ions under stirring, and then filtering, drying and calcining the precipitate produced under alkaline pH conditions, and the hydroxyapatite (HAP) is natural.

8. The method according to claim 6, characterized in that, The metal phosphate M2(PO4) x It is obtained by mixing an aqueous solution of soluble calcium salt with an aqueous solution of ammonium salt containing phosphate ions under stirring, and then filtering, drying and calcining the precipitate produced under alkaline pH.

9. The method according to claim 7 or 8, characterized in that, The impregnation process lasts for 4-24 hours; the reduction process lasts for 1-8 hours.

10. Use of the supported catalyst according to any one of claims 1 to 5 for catalytic hydrogenation reduction reaction.

11. The use according to claim 10, characterized in that, The supported catalyst is used for the preparation of furfuryl alcohol and / or tetrahydrofurfuryl alcohol by catalytic hydrogenation of furfural, the preparation of benzyl alcohol by catalytic hydrogenation of benzaldehyde, or the preparation of aniline by catalytic hydrogenation of nitrobenzene.

12. The use according to claim 10 or 11, characterized in that, The catalytic hydrogenation reduction reaction is carried out at an H2 pressure of 0.1-2 MPa and a temperature of 30-140 °C.

13. The use according to claim 12, characterized in that, The reaction for the preparation of furfural and / or tetrahydrofurfural by catalytic hydrogenation is carried out at a temperature of 40-120°C.

14. The use according to claim 12, characterized in that, The reaction of benzaldehyde to benzyl alcohol by catalytic hydrogenation is carried out at a temperature of 50-120℃.

15. The use according to claim 12, characterized in that, The reaction for the preparation of aniline by catalytic hydrogenation of nitrobenzene is carried out at temperatures of 60-140℃.

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