WO2024239574A1 - 碳包覆镍钯合金纳米粒子的复合材料及其制备方法和应用 - Google Patents

碳包覆镍钯合金纳米粒子的复合材料及其制备方法和应用 Download PDF

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WO2024239574A1
WO2024239574A1 PCT/CN2023/134959 CN2023134959W WO2024239574A1 WO 2024239574 A1 WO2024239574 A1 WO 2024239574A1 CN 2023134959 W CN2023134959 W CN 2023134959W WO 2024239574 A1 WO2024239574 A1 WO 2024239574A1
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Prior art keywords
composite material
nickel
palladium
sulfur
catalyst
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English (en)
French (fr)
Inventor
吴耿煌
荣峻峰
张云阁
王凡非
于鹏
周宇翔
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Sinopec Research Institute of Petroleum Processing
China Petroleum and Chemical Corp
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Sinopec Research Institute of Petroleum Processing
China Petroleum and Chemical Corp
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
    • B01J23/70—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper
    • B01J23/89—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper combined with noble metals
    • B01J23/892—Nickel and noble metals
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J27/00—Catalysts comprising the elements or compounds of halogens, sulfur, selenium, tellurium, phosphorus or nitrogen; Catalysts comprising carbon compounds
    • B01J27/02—Sulfur, selenium or tellurium; Compounds thereof
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J31/00—Catalysts comprising hydrides, coordination complexes or organic compounds
    • B01J31/02—Catalysts comprising hydrides, coordination complexes or organic compounds containing organic compounds or metal hydrides
    • B01J31/0215—Sulfur-containing compounds
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J31/00—Catalysts comprising hydrides, coordination complexes or organic compounds
    • B01J31/02—Catalysts comprising hydrides, coordination complexes or organic compounds containing organic compounds or metal hydrides
    • B01J31/0215—Sulfur-containing compounds
    • B01J31/0229—Sulfur-containing compounds also containing elements or functional groups covered by B01J31/0201 - B01J31/0214
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C209/00—Preparation of compounds containing amino groups bound to a carbon skeleton
    • C07C209/30—Preparation of compounds containing amino groups bound to a carbon skeleton by reduction of nitrogen-to-oxygen or nitrogen-to-nitrogen bonds
    • C07C209/32—Preparation of compounds containing amino groups bound to a carbon skeleton by reduction of nitrogen-to-oxygen or nitrogen-to-nitrogen bonds by reduction of nitro groups
    • C07C209/36—Preparation of compounds containing amino groups bound to a carbon skeleton by reduction of nitrogen-to-oxygen or nitrogen-to-nitrogen bonds by reduction of nitro groups by reduction of nitro groups bound to carbon atoms of six-membered aromatic rings in presence of hydrogen-containing gases and a catalyst
    • C07C209/365—Preparation of compounds containing amino groups bound to a carbon skeleton by reduction of nitrogen-to-oxygen or nitrogen-to-nitrogen bonds by reduction of nitro groups by reduction of nitro groups bound to carbon atoms of six-membered aromatic rings in presence of hydrogen-containing gases and a catalyst by reduction with preservation of halogen-atoms in compounds containing nitro groups and halogen atoms bound to the same carbon skeleton

Definitions

  • the present invention relates to a composite material of carbon-coated nickel-palladium alloy nanoparticles, a preparation method and application thereof, and more specifically, to a composite material of carbon-coated nickel-palladium alloy nanoparticles having a core-shell structure, a preparation method of the composite material, and application of the composite material in a catalytic reaction.
  • Metal particles have a long history as active components of catalysts and are widely used.
  • palladium In the field of catalytic hydrogenation, palladium is generally more active than nickel.
  • palladium In the hydrodechlorination reaction, palladium is generally recognized to have the highest catalytic activity.
  • Metal particle agglomeration is one of the main reasons for catalyst deactivation.
  • the particle size is reduced to a certain extent, it may even bring safety hazards.
  • nano-scale nickel and palladium can spontaneously combust in the air.
  • metal poisoning is another major cause of catalyst deactivation.
  • Hydrogenation raw materials such as hydrogen and reaction substrates may contain sulfur-containing components, which are common poisons for nickel and palladium. Palladium is more easily poisoned by sulfur-containing components than nickel.
  • reaction selectivity can be roughly divided into two categories: one is to change the properties of the catalyst during the catalyst manufacturing process; the other is to control the reaction conditions or add selectivity regulators during the reaction.
  • a large number of literature on reaction selectivity is for reactions catalyzed by metals or metal oxides, and there are few studies on the effects of adjusting the carbon-coated metal material on the selectivity of the reaction. to improve the selectivity of catalytic reactions.
  • Halogenated aromatic amines are important organic intermediates, and catalytic hydrogenation of halogenated nitroaromatics is the most important synthesis method.
  • Palladium and nickel are both commonly used metals for catalytic hydrogenation of halogenated nitroaromatics.
  • the main problem with catalytic hydrogenation of halogenated nitroaromatics is that dehalogenation reactions are prone to occur.
  • the focus of the prior art is on the atom economy of the reaction; however, even if only a small amount of dehalogenation reaction occurs, the generated hydrogen halide can still cause catalyst halogen poisoning and metal loss, resulting in a decrease in catalyst performance, so there is still a need for improvement.
  • Catalytic hydrogenation of halogenated nitroaromatics is a complex reaction process, and the reaction mechanism is different for different catalytic systems.
  • One of the main ways to solve the dehalogenation problem in the prior art is to add a dehalogenation inhibitor during the reaction process.
  • Dehalogenation inhibitors are usually compounds containing nitrogen, sulfur, and phosphorus, which block some highly active sites by combining these heteroatoms with the metal surface, thereby inhibiting the dehalogenation reaction.
  • the disadvantage is that these heteroatoms have a strong effect on the metal surface, and it is easy to form chemical adsorption bonds or directly react with the active center. Therefore, their type and dosage are very critical. Improper selection will cause the catalyst performance to seriously decline, or even lose its catalytic ability.
  • the prior art can usually only add dechlorination inhibitors during the reaction. These toxic compounds are often present in the reaction product components, and it is difficult to completely remove them.
  • catalytic hydrodechlorination can be carried out in the gas phase or in the liquid phase.
  • chlorine on aliphatic carbon is easy to remove, while chlorine on aromatic carbon is difficult to remove.
  • catalysts such as platinum, palladium, rhodium, ruthenium, and nickel in hydrodechlorination reactions.
  • palladium has the highest catalytic activity, but palladium is expensive, and the loss and recycling of palladium must be considered.
  • a large amount of HCl will be produced during the catalytic hydrodechlorination process, which is easy to cause catalyst poisoning.
  • the prior art generally adds alkaline substances to protect the active sites of the catalyst.
  • the first object of the present invention is to provide a composite material of carbon-coated nickel-palladium alloy nanoparticles with higher catalytic hydrogenation activity, more stable performance, and stronger resistance to sulfur poisoning.
  • the second object of the present invention is to provide a modified composite material obtained by modifying the above composite material with a sulfur-containing compound.
  • the third object of the present invention is to provide a method and application of using the above composite material or modified composite material as a catalyst for hydrogenation reaction in the presence of a sulfur-containing compound.
  • the fourth object is to provide a method and application of the composite material or modified composite material as a catalyst for hydrogenation of nitro compounds.
  • the fifth object of the present invention is to provide a method and application of the composite material or modified composite material as a catalyst for selective hydrogenation of halogenated nitroaromatics.
  • the sixth object of the present invention is to provide a method and application of the composite material as a catalyst for catalytic hydrogenation removal of organic chlorine.
  • the present invention provides the following technical solutions.
  • a composite material of carbon-coated nickel-palladium alloy nanoparticles comprising a core-shell structure having a shell layer and a core, the shell layer being a graphitized carbon layer, and the core being a nickel-palladium alloy nanoparticle; in the composite material, the mass ratio of nickel to palladium is 3:1 to 100:1; based on the mass of the composite material, the total mass fraction of nickel and palladium is 1% to 80%.
  • a composite material according to any of the foregoing wherein, in the XRD spectrum of the composite material, there is a diffraction peak in the range of 2 ⁇ of 24° to 26°; and/or, in the XRD spectrum of the composite material, there is a diffraction peak in the range of 2 ⁇ of 43° to 45°, 50° to 54°, 75° to 80°.
  • a composite material according to any of the foregoing wherein, in the XRD spectrum of the composite material, there is no diffraction peak within the range of 40.0° ⁇ 0.1°.
  • a method for preparing a composite material of carbon-coated nickel-palladium alloy nanoparticles comprising the following steps:
  • S2 pyrolyzes the precursor in an inert gas.
  • the first solvent is water and/or ethanol, preferably water.
  • organic polycarboxylic acid is one or more of citric acid, ethylenediaminetetraacetic acid, 2,5-pyridinedicarboxylic acid, malic acid, tartaric acid and terephthalic acid.
  • a preparation method according to any of the above; wherein, calculated on a metal element basis, the mass ratio of the nickel source to the palladium source is 3:1 to 100:1, preferably 4:1 to 100:1, and more preferably 4:1 to 9:1.
  • a preparation method according to any of the above; wherein the molar ratio of the total amount of the nickel source and the palladium source to the organic polycarboxylic acid is 0.1:1 to 3:1, preferably 0.3:1 to 1.5:1, wherein the total amount of the nickel source and the palladium source is calculated based on the total molar amount of the metal elements.
  • the pyrolysis temperature is 500°C to 800°C, preferably 500°C to 700°C, and more preferably 550°C to 650°C.
  • a composite material of modified carbon-coated nickel-palladium alloy nanoparticles wherein the composite material comprises the composite material described in 1 and a sulfur-containing compound loaded thereon.
  • a method for preparing a composite material of modified carbon-coated nickel-palladium alloy nanoparticles comprising: a step of loading a sulfur-containing compound on the composite material described in 1.
  • any of the above composite materials or any of the above modified is used as a hydrogenation catalyst for catalytic hydrogenation.
  • a method for selectively hydrogenating a nitro group in a halogenated nitroaromatic hydrocarbon comprising the following steps: under liquid phase catalytic hydrogenation conditions, in the presence of a sulfur-containing compound, hydrogen is brought into contact with a halogenated nitroaromatic hydrocarbon and a catalyst to carry out a liquid phase catalytic hydrogenation reaction;
  • the catalyst is any one of the composite materials described in 1 to 9 and 25;
  • the sulfur-containing compound is thiocyanate and/or thiourea, and the mass ratio of the sulfur-containing compound to the halogenated nitroaromatic hydrocarbon is 1:100 to 1:10000.
  • a method for selectively hydrogenating a nitro group in a halogenated nitroaromatic hydrocarbon comprising the following steps: contacting hydrogen, the halogenated nitroaromatic hydrocarbon and a catalyst under liquid phase catalytic hydrogenation conditions to carry out a liquid phase catalytic hydrogenation reaction; the catalyst is any composite material described in 19 to 21 and 26.
  • a method for removing organic chlorine by catalytic hydrogenation comprising the following steps: contacting a chlorine-containing saturated or aromatic organic compound with hydrogen and a catalyst for reaction under liquid phase catalytic hydrogenation dechlorination reaction conditions; the catalyst is a composite material described in any one of 1 to 9 and 25.
  • the dechlorination method according to 33 is characterized in that the reaction conditions of the liquid phase catalytic hydrogenation dechlorination are: temperature range 40-120°C, preferably 60-100°C, hydrogen pressure range 0.1-3MPa, preferably 1-2MPa.
  • the dechlorination method according to 33 is characterized in that the chlorine-containing aromatic organic compound is one or more selected from monochlorophenol, dichlorophenol, trichlorophenol, chlorinated aromatic hydrocarbons, 2,4-dichlorophenoxyacetic acid and chloronitrobenzene.
  • the dechlorination method according to 33 is characterized in that the chlorine-containing saturated organic compound is one or more selected from chlorinated saturated aliphatic hydrocarbons.
  • the dechlorination method according to 33 characterized in that a solvent is used in the method;
  • the solvent is one or more selected from isopropanol, ethanol, acetone, tetrahydrofuran, cyclohexane and water.
  • the dechlorination method according to 33 is characterized in that the mass ratio of the catalyst to the chlorine-containing saturated or aromatic organic compound as the reaction substrate is 0.05-0.8:1, preferably 0.1-0.3:1.
  • the dechlorination method according to 33 is characterized in that it further comprises the step of separating the composite material by magnetic separation.
  • the dechlorination method according to 33 is characterized in that the mass ratio of nickel to palladium in the composite material is 3:1 to 10:1, preferably 3:1 to 6:1.
  • the dechlorination method according to 33 is characterized in that, based on the composite material, the total mass fraction of nickel and palladium is 20% to 80%, preferably 50% to 80%.
  • the present invention has the following beneficial technical effects.
  • the present invention utilizes the ability of nickel to promote carbon graphitization, combined with the specific complexing and reducing ability of organic polycarboxylic acids, thereby, a nickel-palladium alloy can be coated in a carbon shell in the form of nanoparticles in a simple method, and the coating is relatively tight. Therefore, on the basis of a nickel source compound, when a palladium source compound is further combined, a composite material of carbon-coated nickel-palladium alloy nanoparticles can be obtained in a simple method, thereby achieving effective coating of palladium.
  • the composite material has both the stability of nano-carbon materials and the catalytic characteristics of palladium metal nanoparticles.
  • the composite material has intrinsic safety, and theoretically there is no problem of metal particle agglomeration, deactivation and loss, nor is there a problem of metal active component poisoning, and in hydrogenation reactions, it exhibits a catalytic activity higher than that of a carbon-coated nickel nanoparticle composite material.
  • the present invention can also conveniently modify the composite material as needed, thereby adjusting the catalytic properties of the composite material, and then making it suitable for different uses, such as selective hydrogenation of nitro groups in organic compounds; hydrogenation removal of chlorine atoms in organic compounds.
  • selective hydrogenation of nitro groups in organic compounds such as hydrogenation of nitro groups in organic compounds; hydrogenation removal of chlorine atoms in organic compounds.
  • the nitro group in the organic compound can be highly selectively hydrogenated.
  • the catalyst has intrinsic resistance to chlorine poisoning and resistance to active metal loss, and therefore, can show excellent catalytic effect.
  • the catalytic active component is an alloy and the palladium content is low, but it still has the catalytic hydrogenation and dechlorination ability of palladium; no alkali is used in the reaction, and it still has a high dechlorination activity; the dechlorination activity is very high when the solvent contains water or does not contain water.
  • the composite material and modified composite material have strong magnetism. After the reaction in which they act as catalysts is completed, magnetic separation can be used to conveniently recover the composite material and modified composite material used as catalysts.
  • Figure 1 is a spherical aberration electron microscope image of the composite material prepared according to Preparation Example 3;
  • Figure 1 (a) spherical aberration electron microscope photo,
  • FIG. 2 is an XRD pattern of the composite material prepared according to Preparation Example 3.
  • FIG. 3 is an XPS broad spectrum of the composite material prepared according to Preparation Example 4.
  • FIG. 4 is a morphological photograph of the composite material prepared according to Preparation Example 1 in the presence of a magnetic field.
  • any matters or items not mentioned are directly applicable to the contents known in the art without any changes.
  • any embodiment described herein can be freely combined with one or more other embodiments described herein, and the technical solutions or technical ideas formed thereby are regarded as part of the original disclosure or record of the present invention, and should not be regarded as new contents not disclosed or anticipated herein, unless a person skilled in the art considers that the combination is obviously unreasonable.
  • graphitized carbon layer refers to a layered carbon structure, rather than an amorphous structure, that can be clearly observed under a high-resolution transmission electron microscope.
  • pores is defined as pores with a pore size in the range of 2 nm to 50 nm. Pores with a pore size less than 2 nm are defined as micropores, and pores with a pore size greater than 50 nm are defined as macropores.
  • acid treatment refers to the operation of acid washing the product generated after the high-temperature pyrolysis step at a temperature close to the boiling temperature of the acid solution when preparing the composite material of carbon-coated nickel-palladium alloy nanoparticles.
  • inert gas is defined as a gas that has no appreciable effect on the catalytic hydrogenation performance of the composite material, including but not limited to nitrogen, helium, argon, etc.
  • soluble means soluble in the solvent in which it is used.
  • PPMw stands for parts per million by weight.
  • the first aspect of the present invention provides a composite material of carbon-coated nickel-palladium alloy nanoparticles, which contains a core-shell structure having a shell layer and a core, wherein the shell layer is a graphitized carbon layer, and the core is a nickel-palladium alloy nanoparticle; in the composite material, the mass ratio of nickel to palladium is 3:1 to 100:1; based on the mass of the composite material, the total mass fraction of nickel and palladium is 1% to 80%.
  • the composite material of the first aspect is composed of nickel, palladium, carbon and oxygen.
  • the composite material of the present invention is mainly composed of zero-valent nickel, palladium and carbon. Since the carbon source in the synthetic raw material contains oxygen, it is inevitable that a small amount of oxygen will be mixed in the surface carbon of the composite material; the composite material will also adsorb oxygen on the surface when stored in the air, and a small amount or trace amount of nickel and palladium may exist in the form of oxidation state. Impurities in the synthetic raw material may also cause a small amount or trace amount of other elements, but these factors have no obvious effect on the performance of the composite material; the present invention believes that it is not necessary to specify these.
  • the mass ratio of nickel to palladium is 3:1 to 100:1, preferably 4:1 to 100:1; if a relatively higher catalytic hydrogenation activity is required, the mass ratio of nickel to palladium can be further controlled between 4:1 and 9:1, and can also be controlled between 3:1 and 10:1, or between 3:1 and 6:1.
  • the XRD spectrum of the composite material only has diffraction peaks of fccNiPd alloy. If the palladium content is too high, characteristic peaks of elemental palladium will appear in the XRD spectrum, and these elemental palladium are not tightly coated by carbon and do not have the ability to resist agglomeration and poisoning deactivation.
  • the total mass fraction of nickel and palladium is 1% to 80%, preferably 20% to 80%, more preferably 30% to 80%, more preferably 50% to 80%, more preferably 50% to 78%.
  • the present invention has found that even if about 1% palladium is doped in nickel, the catalytic hydrogenation capacity of the composite material is significantly improved. In some embodiments of the present invention, even after acid treatment, the total mass fraction of nickel and palladium in the composite material can still reach about 75%.
  • the shell structure is composed of a graphitized carbon layer.
  • the shell structure of the present invention is not doped with other elements.
  • the composite material of the present invention may contain a trace amount of amorphous carbon, which exists only as an impurity and the present invention does not intend to limit it.
  • the composite material of the first aspect is a mesoporous and/or macroporous material, and the volume of mesopores and/or macropores accounts for more than 50% of the total pore volume.
  • the composite material has a mesoporous structure or a mesoporous and macroporous structure. It is well known in the art that the pore structure is a macroscopic property of the catalyst.
  • the composite material according to the first aspect has a specific surface area of 50 m 2 /g to 500 m 2 /g, preferably 100 m 2 /g to 300 m 2 /g.
  • the particle size of the nickel-palladium alloy nanoparticles is 1nm to 50nm, generally between 2nm and 25nm, preferably between 3nm and 15nm. In some embodiments, the particle size distribution of the nickel-palladium alloy nanoparticles is relatively narrow, generally between 4nm and 10nm.
  • the thickness of the graphitized carbon layer is 0.5 nm to 10 nm, preferably 0.5 nm to 5 nm, and generally between 1 nm and 5 nm.
  • the core-shell structure is spherical or quasi-spherical.
  • the XRD spectrum of the composite material has only one diffraction peak in the range of 40.1° to 44.5° at 2 ⁇ .
  • the composite material of the first aspect in the XRD spectrum of the composite material, there is a diffraction peak in the range of 2 ⁇ of 24° to 26°; and/or, in the XRD spectrum of the composite material, there is a diffraction peak in the range of 2 ⁇ of 43° to 45°, 50° to 54°, 75° to 80°.
  • the composite material of the first aspect in the XRD spectrum of the composite material, there is no diffraction peak within the range of 40.0° ⁇ 0.1°.
  • the second aspect of the present invention provides a composite material of modified carbon-coated nickel-palladium alloy nanoparticles (hereinafter, sometimes also referred to as a modified composite material), which comprises the composite material of the first aspect and sulfur-containing compounds supported thereon.
  • the modified composite material according to the second aspect is composed of the composite material according to the first aspect and a sulfur-containing compound supported thereon.
  • the molecular weight of the sulfur-containing compound is generally less than 200.
  • the sulfur-containing compound can be either an organic sulfur compound or an inorganic sulfur compound; in the organic sulfur compound, the carbon-sulfur bond can be either a double bond or a single bond.
  • the sulfur-containing compound is preferably thiourea.
  • the mass fraction of sulfur obtained by elemental analysis may be 0.1% to 10%, preferably 0.5% to 5%, and more preferably 0.8% to 1.8%.
  • the third aspect of the present invention provides a method for preparing the composite material of the first aspect, comprising the following steps:
  • S2 pyrolyzes the precursor in an inert gas.
  • the first solvent is water and/or ethanol, preferably water.
  • the nickel source is a soluble nickel salt, which may be one or more of nickel acetate, basic nickel carbonate and nickel carbonate.
  • the palladium source is a palladium-containing solution, which may be a solution of palladium acetate, and preferably a solution of palladium acetate in glacial acetic acid.
  • the organic polycarboxylic acid provides a carbon source for the composite material and plays a role as a complexing agent. It is preferably an organic polycarboxylic acid containing hydroxyl groups in the molecule.
  • the organic polycarboxylic acid can be one or more of citric acid, ethylenediaminetetraacetic acid, 2,5-pyridinedicarboxylic acid, tartaric acid or terephthalic acid, preferably citric acid.
  • the mass ratio of the nickel source to the palladium source, calculated as metal elements is 3:1 to 100:1, preferably 4:1 to 100:1, and more preferably 4:1 to 9:1.
  • the molar ratio of the total amount of the nickel source and the palladium source to the organic polycarboxylic acid is 0.1:1 to 3:1, preferably 0.3:1 to 1.5:1, wherein the total amount of the nickel source and the palladium source is calculated based on the total molar amount of the metal elements.
  • the precursor solution can be prepared by the following method: adding a nickel source, a palladium source and an organic polycarboxylic acid as a carbon source to water and/or ethanol, stirring at 40°C to 100°C for 8h to 16h, preferably stirring at 50°C to 90°C for 10h to 16h. 12h; wherein the palladium source is provided in the form of a glacial acetic acid solution in which 0.5g to 1.1g of palladium acetate is dissolved in 100mL of glacial acetic acid, and the nickel source is provided in the form of nickel acetate (which may or may not contain crystal water).
  • the amount of the nickel source is adjusted so that the mass ratio of the nickel source to the palladium source is 3:1 to 100:1, preferably 4:1 to 100:1, and more preferably 4:1 to 9:1, based on the metal element;
  • the amount of the polycarboxylic acid is adjusted so that the molar ratio of the total amount of the nickel source and the palladium source to the organic polycarboxylic acid is 0.1:1 to 3:1, preferably 0.3:1 to 1.5:1.
  • the first solvent in the precursor solution is preferably removed by direct evaporation.
  • the first solvent in the precursor solution can be evaporated on a rotary evaporator and/or dried in an oven.
  • S2 satisfies at least one of the following conditions: the pyrolysis temperature is 500°C to 800°C, preferably 500°C to 700°C, and more preferably 550°C to 650°C; and/or the pyrolysis time is 1h to 4h, preferably 1.5h to 3h; and/or the heating rate is 1°C/min to 10°C/min, preferably 2°C/min to 5°C/min.
  • the inert gas may be nitrogen, argon or helium.
  • the preparation method according to the third aspect also includes an optional acid treatment step after S2.
  • the present invention does not limit the type, amount and treatment time of the acid used for the acid treatment, and those skilled in the art can choose according to existing knowledge and/or simple experiments.
  • Acid treatment is generally performed with a non-oxidizing strong acid, such as hydrochloric acid or sulfuric acid.
  • hydrochloric acid is used, and the concentration can be 0.5mol/L ⁇ 2mol/L, the temperature can be 60°C ⁇ 100°C, which can be close to the boiling temperature of the acid solution, and the time can be 3h ⁇ 24h, and can also be 3h ⁇ 10h.
  • the preparation method according to the third aspect also includes a post-processing step of acid washing the product, such as filtering, washing, drying, etc.
  • the fourth aspect of the present invention provides a method for preparing the modified composite material of the second aspect (hereinafter sometimes referred to as "method for preparing the modified composite material"), which comprises the step of contacting the composite material of the first aspect with a sulfur-containing compound.
  • the composite material of the first aspect is loaded with a sulfur-containing compound.
  • the preparation method of the modified composite material of the fourth aspect there is no particular limitation on the contacting method of the sulfur-containing compound.
  • Those skilled in the art can use any existing known method to contact the composite material of the first aspect with the sulfur-containing compound to load the sulfur-containing compound on the composite material of the first aspect.
  • a preferred method is to first separate the composite material of the first aspect into The sulfur-containing compound is dispersed in the second solvent, and the sulfur-containing compound is dissolved in the third solvent to prepare a solution; then the two liquids are mixed; in order to make the contact between the two liquids sufficient and uniform, mechanical stirring and mixing can be adopted, or ultrasonic mixing can be adopted; or the two liquids can be combined, ultrasonic mixing first, and then mechanical stirring and mixing.
  • the contact time can be 12h to 24h.
  • the second solvent is water and/or an alcohol solvent, preferably water.
  • the third solvent is water and/or an alcohol solvent, preferably water.
  • the sulfur-containing compound is thiourea.
  • the first solvent and the second solvent are preferably water.
  • the ultrasonic time is 0.5h to 3h
  • the mechanical stirring time is 2h to 24h
  • the load temperature is 25°C to 90°C.
  • the type and amount of the sulfur-containing compound can vary within a wide range.
  • the present invention has found that the use of sulfur-containing compounds to treat the composite material of the first aspect can significantly affect the selectivity during the catalytic hydrogenation reaction.
  • Those skilled in the art can select appropriate sulfur-containing compounds and determine their amounts through experiments according to actual needs.
  • different small molecule sulfur-containing compounds have different effects on the composite material. For example, when thiourea is used in the catalytic hydrogenation reaction of para-halonitrobenzene, the selectivity can reach 100%.
  • the sulfur-containing compound can be loaded by an impregnation method.
  • the amount of the sulfur-containing compound in terms of sulfur element can be 0.01 mol to 20 mol, preferably 0.3 mol to 5 mol, relative to 1 mol of palladium element in the composite material of the first aspect.
  • the preparation method according to the fourth aspect also includes the step of post-processing the product after loading, such as filtering, washing, drying, etc.
  • the fifth aspect of the present invention provides a composite material of carbon-coated nickel-palladium alloy nanoparticles prepared by the preparation method of any of the aforementioned aspects.
  • the sixth aspect of the present invention provides a composite material of modified carbon-coated nickel-palladium alloy nanoparticles obtained by the preparation method of the modified composite material according to any of the aforementioned aspects.
  • the seventh aspect of the present invention provides use of the composite material of any of the aforementioned aspects or the modified composite material of any of the aforementioned aspects as a hydrogenation catalyst when the catalytic hydrogenation system contains sulfur.
  • the hydrogen and/or the hydrogenation substrate may contain sulfur.
  • the production of hydrogen from fossil fuels is the main way to obtain industrial hydrogen in the petrochemical industry. Sulfur compounds are inevitably produced in the process.
  • pressure swing adsorption (PSA) technology can make the hydrogen purity reach more than 99.9%, there are still sulfur compounds in the hydrogen; some reaction substrates themselves contain sulfur, such as thionitroaromatics, etc.; sulfur-containing impurities may also exist in the reaction substrates, and the influence of these sulfur-containing compounds on the hydrogenation catalyst cannot be ignored.
  • the present invention has found that even if the composite material of the present invention is treated with thiourea with a high concentration and high toxicity, it still has a high catalytic hydrogenation activity, so it has a unique advantage when used as a hydrogenation catalyst in a catalytic hydrogenation system under the condition of the presence of these sulfur-containing compounds.
  • the hydrogenation substrate contains one or more functional groups selected from the group consisting of a nitro group, a carbon-carbon double bond, a carbon-carbon triple bond, a ketone group, an aldehyde group, and an aromatic ring.
  • the prior art has achieved hydrogenation of the above functional groups using a carbon-coated nickel nanoparticle composite material or a modified composite material.
  • the composite material and the modified composite material of the present invention have higher catalytic hydrogenation activity than the carbon-coated nickel nanoparticle composite material, and thus can also catalytically hydrogenate the above functional groups contained in organic compounds.
  • the eighth aspect of the present invention provides a method for selectively hydrogenating the nitro group of thionitroaromatic hydrocarbons, comprising the following steps: under liquid phase catalytic hydrogenation conditions, hydrogen and thionitroaromatic hydrocarbons are contacted with a catalyst to carry out a liquid phase catalytic hydrogenation reaction; the catalyst is the composite material of the first or fifth aspect or the modified composite material of the second or sixth aspect.
  • the thionitroarene has a structure as shown in formula (I):
  • X is selected from one or more of sulfur and sulfone
  • R1 is selected from one or more of hydrogen, C1-C6 hydrocarbon group, C1-C3 halogenated hydrocarbon group, C1-C3 hydroxyl hydrocarbon group, thiol group, C6-C10 aryl group and C6-C10 arylthio group
  • R2 is selected from one or more of hydrogen, C1-C6 hydrocarbon group, hydroxyl, carboxyl, halogen, amino, thiol group, C6-C10 aryl group, C6-C10 arylthio group and nitro group
  • the aryl group is unsubstituted or substituted by one or more of the following groups: nitro, C1-C6 hydrocarbon group, hydroxyl, carboxyl, halogen, amino or amino group.
  • the hydrocarbon group may be an alkyl, alkenyl or alkynyl, preferably an alkyl.
  • the aryl group may be phenyl or naphthyl.
  • the halogen and the halogen in the halogenated group may be Fluorine, chlorine, bromine, iodine.
  • Common thionitroaromatics include 4-nitrothioanisole, 2-nitrodiphenyl sulfide, 4-nitrothiophenol, 3,3'-dinitrodiphenyl sulfone and 4,4'-dinitrodiphenyl sulfone.
  • the prior art has achieved hydrogenation of the above compounds using carbon-coated nickel nanoparticle composite materials.
  • the composite material and modified composite material of the present invention have higher catalytic hydrogenation activity than the carbon-coated nickel nanoparticle composite material, and thus can also catalytically hydrogenate the above organic compounds.
  • the ninth aspect of the present invention provides a method for selectively hydrogenating the nitro group in halogenated nitroaromatics, comprising the following steps: under liquid phase catalytic hydrogenation conditions, in the presence of a sulfur-containing compound, hydrogen and halogenated nitroaromatics are contacted with a catalyst to carry out a liquid phase catalytic hydrogenation reaction;
  • the catalyst is the composite material of the first or fifth aspect of the present invention;
  • the sulfur-containing compound is thiocyanate and/or thiourea, and the mass ratio of the sulfur-containing compound to the halogenated nitroaromatics is 1:100 to 1:10000.
  • the present invention has found that the addition of sulfur-containing compounds can significantly affect the selectivity of the catalytic hydrogenation reaction.
  • Those skilled in the art can select appropriate sulfur-containing compounds and determine their dosage according to actual needs through experiments.
  • the molecular weight of the sulfur-containing compound is generally below 200, which makes the operation more convenient; the dosage range is generally wide, making the control easier.
  • different small molecular sulfur-containing compounds have different effects on the selectivity of the reaction. For example, for the selective hydrogenation of chloronitrobenzene to produce chloroaniline, the selectivity of sodium sulfide is only 70% to 80%, the selectivity of thiocyanate is above 98%, and the selectivity of thiourea can reach 100%.
  • the thiocyanate is generally potassium thiocyanate and/or sodium thiocyanate.
  • the mass ratio of the sulfur-containing compound to the halogenated nitroaromatic hydrocarbon is preferably 1:100 to 1:150.
  • the mass ratio of the catalyst to the halogenated nitroaromatic hydrocarbon is 1:1 to 1:15, preferably 1:1 to 1:7.
  • the conditions for the liquid phase catalytic hydrogenation are: the temperature is 20°C to 100°C, preferably 40°C to 60°C; and/or the hydrogen pressure is 0.5MPa to 4MPa, preferably 0.8MPa to 2MPa.
  • the liquid phase hydrogenation reaction uses a solvent, and the solvent is selected from one or more of isopropanol, ethanol, acetone and water, preferably isopropanol and/or water, and more preferably a mixed solvent with a volume ratio of isopropanol to water of 10:1 to 5:1.
  • the halogenated nitroaromatic hydrocarbon is chloronitrobenzene, preferably m-chloronitrobenzene or p-chloronitrobenzene.
  • the tenth aspect of the present invention provides another method for selectively hydrogenating the nitro group in halogenated nitroaromatic hydrocarbons, comprising the following steps: under liquid phase catalytic hydrogenation conditions, hydrogen and halogenated nitroaromatic hydrocarbons are contacted with a catalyst to carry out a liquid phase catalytic hydrogenation reaction; the catalyst is the modified composite material of the second or sixth aspect of the present invention.
  • the mass ratio of the catalyst to the halogenated nitroaromatic hydrocarbon is 1:1 to 1:15, preferably 1:1 to 1:7.
  • the conditions for the liquid phase catalytic hydrogenation are: the temperature is 20°C to 100°C, preferably 40°C to 60°C; and/or the hydrogen pressure is 0.5MPa to 4MPa, preferably 0.8MPa to 2MPa.
  • the liquid phase hydrogenation reaction uses a solvent, and the solvent is selected from one or more of isopropanol, ethanol, acetone and water, preferably isopropanol and/or water.
  • the halogenated nitroaromatic hydrocarbon is chloronitrobenzene, preferably m-chloronitrobenzene or p-chloronitrobenzene.
  • the eleventh aspect of the present invention provides a method for catalytic hydrogenation removal of organic chlorine, comprising: under the reaction conditions of liquid phase catalytic hydrogenation dechlorination, contacting a chlorine-containing saturated or aromatic organic compound with hydrogen and a catalyst for reaction; the catalyst is a composite material of the first or fifth aspect of the present invention.
  • the mass ratio of nickel to palladium is 3:1 to 10:1, preferably 3:1 to 8:1, and more preferably 3:1 to 6:1.
  • the total mass fraction of nickel and palladium is 20% to 80%, preferably 30% to 80%, and more preferably 50% to 80%.
  • reaction conditions of the liquid phase catalytic hydrodechlorination are: temperature range 40-120° C., preferably 60-100° C., hydrogen pressure range 0.1-3 MPa, preferably 1-2 MPa.
  • the chlorine-containing aromatic organic compound preferably has a chlorine atom directly connected to an aromatic ring, and is more preferably selected from one or more of monochlorophenol, dichlorophenol, trichlorophenol, chlorinated aromatic hydrocarbons, 2,4-dichlorophenoxyacetic acid and chloronitrobenzene.
  • the chlorine-containing saturated organic compound is one or more selected from chlorinated saturated aliphatic hydrocarbons.
  • a solvent may or may not be used in the method.
  • the use of solvent depends on whether the reaction substrate itself is in a suitable liquid state under hydrogenation conditions, and the needs of those skilled in the art; the choice of solvent depends on ensuring that the reaction substrate can be dissolved, which is known in the art.
  • water itself is the solvent.
  • solvents that can be used in the eleventh aspect of the present invention include, but are not limited to, one or more of isopropanol, ethanol, acetone, tetrahydrofuran, cyclohexane and water. If the organic chloride is soluble in alcohol but insoluble in water, a mixed solvent of alcohol and water is preferably used, and the volume ratio of alcohol to water is preferably 10:1 to 5:1.
  • the ratio of the catalyst to the chlorine-containing saturated or aromatic organic compound as a reaction substrate is 0.05 to 0.8:1 by mass ratio, preferably 0.1 to 0.3:1.
  • the dechlorination method can be used in the fields of sewage dechlorination treatment, crude oil dechlorination pretreatment, organic by-product dechlorination recovery and organic synthesis.
  • the composite material and modified composite material of the present invention have strong magnetism, in the above methods of the present invention, after the reaction is completed, magnetic separation can be used to conveniently recover the composite material and modified composite material used as a catalyst.
  • the surface morphology of the material was characterized by high-resolution transmission electron microscopy (HRTEM, JEOL Ltd., JEM-2100) with an accelerating voltage of 200 kV.
  • the distribution of each element in the material was characterized by spherical aberration electron microscopy (STEM).
  • STEM spherical aberration electron microscopy
  • JEM-ARM200F JEM-ARM200F (JEOL Ltd.)
  • acceleration voltage was 200 kV.
  • XRD is used to obtain information such as the composition of the material, the structure or morphology of the atoms or molecules inside the material, etc.
  • the XRD diffractometer used is an X’Pert Pro X-ray diffractometer purchased from PA Nalytical in the Netherlands.
  • the test conditions are: Cu target, K ⁇ ray, tube voltage of 40kV, tube current of 40mA, and 2 ⁇ scanning range of 5° to 80°.
  • the elements on the surface of the material were detected by X-ray photoelectron spectroscopy (XPS).
  • XPS X-ray photoelectron spectroscopy
  • the X-ray photoelectron spectroscopy analyzer used was an ESCALab220i-XL X-ray electron spectrometer produced by VG Scientific and equipped with Avantage V5.926 software.
  • the X-ray photoelectron spectroscopy analysis test conditions were: the excitation source was monochromatic A1K ⁇ X-ray, the power was 330W, and the basic vacuum during the analysis test was 3 ⁇ 10-9mbar.
  • BET Brunauer-Emmett-Taller method
  • the content of carbon, hydrogen, oxygen, nitrogen and sulfur elements is tested on the Elementar Vario EL Cube elemental analyzer.
  • the specific operation method is as follows: the sample is weighed in a tin cup of about 5 mg, placed in an automatic sample tray, and enters the combustion tube through a ball valve for combustion.
  • the combustion temperature is 1000°C (in order to eliminate atmospheric interference during injection, helium is used for purging).
  • the C, H, N, and S in the sample are converted into carbon dioxide, water, nitrogen, and sulfur dioxide, respectively.
  • the mixed gas is separated by a chromatographic column and finally detected by a thermal conductivity cell.
  • the sample When determining the oxygen element, the sample is cracked in a high-temperature cracking tube filled with carbon powder, and the oxygen in the sample is converted into carbon monoxide.
  • the carrier gas carries the cracking product into the series-connected scrubber to remove acid gas and water vapor, and finally enters the infrared detector for detection.
  • the content of nickel and palladium elements was determined by inductively coupled plasma optical emission spectrometry (ICP-OES), and the specific method is as follows: (1) Nitrolysis: 10 mg of the catalyst sample was placed in a flask, 16 mL of freshly prepared aqua regia was added, a magnetic stirrer was added, the flask was placed in an oil bath, refluxed at 120°C for 12 h, cooled to room temperature, the solution was drawn up by a glass syringe, filtered with a disposable filter head with a pore size of 0.22 ⁇ m, the filtrate was added to a 500 mL volumetric flask, and the volume was fixed with ultrapure water. (2) Content test: 10 mL of the solution after nitrolysis was taken and the metal content was tested using the instrument Agilent5110.
  • step 2) placing the precursor obtained in step 1) in a porcelain boat, and then placing the porcelain boat in the constant temperature zone of a tube furnace, introducing nitrogen at a flow rate of 150 mL/min, and heating to 600°C at a rate of 2.5°C/min. After keeping the temperature constant for 2 hours, stopping heating, and cooling to room temperature under a nitrogen atmosphere to obtain a pyrolysis product.
  • step 3 Add the pyrolysis product obtained in step 2) into 200 mL of 1 mol/L HCl solution, stir and reflux at 90 °C for 4 h, then filter the solution, wash with deionized water until neutral, and dry the powder in an oven at 100 °C for 2 h to obtain a carbon-coated nickel-palladium nanocomposite material.
  • step 1) 0.657g of palladium acetate and 35mL of glacial acetic acid are weighed. Add to 170mL of deionized water and stir to dissolve at 50°C.
  • the mass ratio of nickel source to palladium source of 17:3 in terms of metal elements
  • the molar ratio of the total molar amount of nickel palladium to the complexing agent is 1:1
  • citric acid monohydrate and nickel acetate tetrahydrate are weighed and added to the above solution, stirred at 70°C to obtain a homogeneous solution, and continued to heat and evaporate to dryness, and the solid was ground to obtain a precursor.
  • the rest is the same as in Preparation Example 1 to obtain a carbon-coated nickel-palladium nanocomposite material.
  • step 1) 0.943g of palladium acetate and 60mL of glacial acetic acid are weighed. Add to 170mL of deionized water and stir to dissolve at 50°C.
  • the mass ratio of nickel source to palladium source of 4:1 in terms of metal elements
  • the molar ratio of the total molar amount of nickel palladium to the complexing agent is 1:1
  • citric acid monohydrate and nickel acetate tetrahydrate are weighed and added to the above solution, stirred at 70°C to obtain a homogeneous solution, and continued to heat and evaporate to dryness, and the solid was ground to obtain a precursor.
  • the rest is the same as in Preparation Example 1 to obtain a carbon-coated nickel-palladium nanocomposite material.
  • This preparation example is used to illustrate the sulfur-containing carbon-coated nickel-palladium nanocomposite material.
  • step 2) placing the precursor obtained in step 1) in a porcelain boat, and then placing the porcelain boat in the constant temperature zone of a tube furnace, introducing nitrogen at a flow rate of 150 mL/min, and heating to 600°C at a rate of 2.5°C/min. After keeping the temperature constant for 2 hours, stopping heating, and cooling to room temperature under a nitrogen atmosphere to obtain a pyrolysis product.
  • step 3 Add the pyrolysis product obtained in step 2) into 200 mL of 1 mol/L HCl solution and heat at 90 °C. After stirring and refluxing for 4 h, the solution was filtered and washed with deionized water until neutral. The powder was placed in an oven at 100° C. and dried for 2 h to obtain a carbon-coated nickel-palladium alloy nanocomposite material.
  • Examples 1 to 3 are used to illustrate the method of synthesizing p-chloroaniline by selective hydrogenation of p-chloronitrobenzene using the composite material of the present invention as a catalyst.
  • Example 1 The reaction time of Example 1 until the pressure remained unchanged for 10 minutes was 180 minutes. After analysis of the product, the conversion rate of p-chloronitrobenzene was 100%, and the selectivity of p-chloroaniline was 100%.
  • Example 2 The reaction time of Example 2 until the pressure remained unchanged for 10 minutes was 77 minutes. After analysis of the product, the conversion rate of p-chloronitrobenzene was 100%, and the selectivity of p-chloroaniline was 100%.
  • Example 3 The reaction time of Example 3 until the pressure remained unchanged for 10 minutes was 50 minutes. After analysis of the product, the conversion rate of p-chloronitrobenzene was 100%, and the selectivity of p-chloroaniline was 100%.
  • Example 3 According to the method of Example 3, except that thiourea was replaced by potassium thiocyanate, the rest was the same as Example 3. Under the same conditions, the p-chloronitrobenzene hydrogenation reaction was catalyzed, the p-chloronitrobenzene conversion rate was 100%, and the p-chloroaniline selectivity was 98.84%.
  • Example 1 The method of Example 1 was followed, except that thiourea was not added.
  • the other conditions were the same as those of Example 1.
  • the p-chloronitrobenzene hydrogenation reaction was catalyzed.
  • the p-chloronitrobenzene conversion rate was 100%
  • the p-chloroaniline selectivity was 65.5%
  • the remainder was aniline.
  • Example 3 The method of Example 3 was followed, except that the catalyst was the modified composite material of Preparation Example 4, the dosage was 100 mg, no thiourea was added, the p-nitrochlorobenzene was 157.5 mg, and the rest was the same as Example 3. Under the same conditions, the p-chloronitrobenzene hydrogenation reaction was catalyzed, the p-chloronitrobenzene conversion rate was 100%, and the p-chloroaniline selectivity was 100%.
  • Example 1 According to the method of Example 1, the catalyst was replaced with a commercial palladium carbon catalyst (10wt% Pd, 55% water content), and the rest was the same as Example 1. The catalytic hydrogenation reaction was carried out under the same conditions, and the conversion rate of p-chloronitrobenzene was 0%. It can be seen that the traditional supported Pd catalyst completely loses its catalytic activity in the presence of sulfur-containing poisons and has no ability to resist sulfur poisoning.
  • Example 1 According to the method of Example 1, except that the catalyst was replaced with a commercial palladium-carbon catalyst (10 wt % Pd, 55 % water content), and thiourea was not added, and the rest was the same as in Example 1. Under the same conditions, the p-chloronitrobenzene hydrogenation reaction was catalyzed, and the p-chloronitrobenzene conversion rate was 100%, and the p-chloroaniline content in the product was ⁇ 0. It can be seen that the selectivity of the traditional supported Pd catalyst for p-chloroaniline is very poor.
  • the metal content in the composite materials of the preparation examples is about 75%, that is, the metal content in the composite materials of the present invention is very high and has acid corrosion resistance, which can avoid the loss of active metals when used in an acidic environment.
  • the metal nanoparticles are mixed by nickel and palladium elements at the atomic scale, and other preparation examples of the present invention also have the same characteristics, that is, the metal nanoparticles in the composite material of the present invention are nickel-palladium alloys; other preparation examples of the present invention also have the same characteristics.
  • the particle size of the metal nanoparticles is between 2nm and 25nm
  • the thickness of the graphitized carbon layer is between 1nm and 5nm
  • the carbon-coated nickel-palladium nanoparticle core-shell structure is spherical or quasi-spherical; other preparation examples of the present invention also have the same characteristics.
  • the composite material prepared according to Preparation Example 3 has only the diffraction peak of the fcc NiPd alloy, and no diffraction peaks of elemental nickel and elemental palladium.
  • the other preparation examples of the present invention also have the same characteristics, that is, the metal nanoparticles in the composite material of the present invention are nickel-palladium alloy. gold.
  • the surface layer of the modified composite material prepared according to Preparation Example 4 contains carbon, oxygen, nickel, palladium, sulfur and nitrogen elements.
  • the composite material prepared according to Preparation Example 1 is attracted to the tube wall on the side of the magnet under the action of the magnetic field. When the magnet is removed, the composite material is laid flat in the tube under the action of gravity.
  • Other preparation examples of the present invention also have the same characteristics, that is, the composite material of the present invention has strong ferromagnetism and good fluidity.
  • Example 5 It can be seen from Example 5 that although a small amount of palladium is added to the metal nanoparticles, about 35% of the chlorine can be removed, indicating that the catalytic hydrogenation ability of the composite material is significantly increased, while the metal nanoparticles have basically no hydrogenation and dechlorination ability when they are only elemental nickel.
  • the commercial palladium-carbon catalyst has a high hydrogenation activity, and almost all chlorine is removed when catalyzing the hydrogenation of p-chloronitrobenzene.
  • the commercial palladium-carbon catalyst has no ability to resist sulfur poisoning, and the addition of about 80 PPMw of sulfide can cause it to lose all activity.
  • the composite material of the present invention when a trace amount of sulfide is added to the reaction system, the composite material of the present invention exhibits good resistance to sulfur poisoning, maintains a very high catalytic activity when catalyzing the hydrogenation of p-chloronitrobenzene, and has a highly selective catalytic hydrogenation ability; that is, the composite material of the present invention can be used to catalyze the hydrogenation of halogenated nitroaromatics to produce halogenated aromatic amines with high activity and high selectivity.
  • the modified composite material of the present invention has a high-activity catalytic hydrogenation ability, indicating that the composite material of the present invention has a very strong resistance to sulfur poisoning, and the treated composite material does not need to add sulfide to the reaction system, and can highly selectively catalyze the selective hydrogenation of p-chloronitrobenzene to produce p-chloroaniline; that is, the modified composite material treated with sulfur-containing compounds of the present invention can directly catalyze the hydrogenation of halogenated nitroaromatics with high activity and selectivity to produce halogenated aromatic amines, avoiding the mixing of toxic substances into the hydrogenation product.
  • Examples 7 to 8 illustrate the catalytic hydrodechlorination method using the composite material of the present invention as a catalyst
  • Example 9 It can be seen from Example 9 that, although only an organic solvent is used, the method of the present invention still has a very high catalytic hydrodechlorination capacity.

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Abstract

本发明涉及碳包覆镍钯合金纳米粒子的复合材料及其制备方法和应用，其中的复合材料含有具有壳层和内核的核壳结构，壳层为石墨化碳层，内核为镍钯合金纳米粒子。该复合材料具有本征安全性，可避免金属粒子聚结失活和流失的问题，而且在加氢反应中表现出高于碳包覆镍纳米粒子复合材料的催化活性。

Description

碳包覆镍钯合金纳米粒子的复合材料及其制备方法和应用 技术领域
本发明涉及碳包覆镍钯合金纳米粒子的复合材料及其制备方法和应用。更具体而言，涉及具有核壳结构的碳包覆镍钯合金纳米粒子的复合材料，该复合材料的制备方法，以及该复合材料在催化反应中的应用。
背景技术
金属粒子作为催化剂活性组分的历史悠久、应用广泛。在催化加氢领域，通常钯比镍的催化活性更高，如在加氢脱氯反应中，公认钯的催化活性最高。
金属粒子聚结是催化剂失活的主要原因之一，金属粒子的粒径越小，催化活性越高，但表面能更大，更容易聚结失活。当粒径减小到一定程度时甚至还会带来安全隐患，如纳米级的镍和钯都能在空气中自燃。另外，金属中毒是催化剂失活的另一个主要原因，加氢原料如氢气和反应底物都可能含有含硫成分，而含硫成分是镍和钯的常见毒物，钯比镍更容易被含硫成分毒化。
已有较多文献报道了具有石墨化碳包覆镍纳米粒子核壳结构的复合材料，其核壳结构一般是由厚度10nm以下的石墨烯层包覆的镍纳米粒子，将这种复合材料用于催化加氢反应时，兼具碳纳米材料的稳定性和镍纳米粒子的高活性。CN114425341A较早公开了石墨烯包覆镍纳米粒子的抗硫毒化性能，石墨化碳层的严密包覆是其具备抗硫毒化能力的关键因素之一。尽管现有技术公开了大量的石墨化碳包覆镍纳米材料，但是很难制造出石墨化碳包覆钯的复合材料，涉及石墨化碳包覆钯的文献比较罕见，现有技术中仍缺乏简单有效的石墨化碳包覆钯的制造方法。因此，如何既利用钯催化活性高的优点，又能克服其容易聚结、容易中毒失活的缺点，是现有技术尚未很好解决的技术问题。
提高反应选择性的方法大致可分为两类，一类是在催化剂制造过程中，通过改变催化剂性质来实现；另一类是在反应过程中通过控制反应条件或加入选择性调节剂来实现。大量关于反应选择性的文献是针对金属或金属氧化物催化的反应，罕有关于通过调节碳包覆金属材料 来改善催化反应选择性的文献。
卤代芳胺是重要的有机中间体，卤代硝基芳烃催化加氢是其最重要的合成方法，钯和镍都是卤代硝基芳烃催化加氢常用的金属。卤代硝基芳烃催化加氢最主要的问题是容易发生脱卤反应。现有技术关注的重点在反应的原子经济性；然而，即使仅发生少量脱卤反应，生成的卤化氢仍能导致催化剂卤素中毒和金属流失，导致催化剂性能下降，因此仍有必要改进。
卤代硝基芳烃催化加氢是一个复杂的反应过程，催化体系不同，反应机理也不同。现有技术解决脱卤问题的一个主要途径是在反应过程中加入脱卤抑制剂。脱卤抑制剂通常是含氮、硫、磷的化合物，通过这些杂原子与金属表面结合来封闭部分高活性位点，从而抑制脱卤反应。其不足之处在于，这些杂原子与金属表面的作用强，很容易形成化学吸附键或直接与活性中心反应，因此其种类和用量都十分关键，选择不当会造成催化剂性能严重下降，甚至丧失催化能力。现有技术通常只能在反应时加入脱氯抑制剂，这些有毒化合物往往存在反应产物组分中，很难完全去除它们。
另一方面，催化加氢脱氯可以在气相进行，也可以在液相进行，一般脂肪碳上的氯易脱除，芳香碳上的氯难脱除。目前，已有大量报道公开了铂、钯、铑、钌、镍等催化剂在加氢脱氯反应中的应用，其中钯的催化活性最高，但是钯的价格昂贵，须考虑钯的损耗及回收利用问题。而且，在催化加氢脱氯过程中会产生大量HCl，易造成催化剂中毒，现有技术一般加入碱性物质来保护催化剂的活性位点。现有技术中，已有文献报道了石墨化碳层包覆镍纳米颗粒的复合材料，这种具有核壳结构的复合材料能高效催化不饱和基团加氢，但是，这类复合材料通常无法用于脱氯。
发明内容
本发明的第一个目的是提供一种催化加氢活性更高、性能更稳定、抗硫毒化能力更强的碳包覆镍钯合金纳米粒子的复合材料。本发明的第二个目的是提供用含硫化合物改性上述复合材料而得的改性复合材料。本发明的第三个目的是提供在含硫化合物的存在下将上述复合材料或改性复合材料作为催化剂进行加氢反应的方法和应用。本发明的 第四个目的是提供上述复合材料或改性复合材料作为催化剂用于硝基化合物加氢的方法和应用。本发明的第五个目的是提供上述复合材料或改性复合材料作为催化剂用于卤代硝基芳烃选择性加氢的方法和应用。本发明的第六个目的是提供上述复合材料作为催化剂用于催化加氢脱除有机氯的方法和应用。
为实现上述目的，本发明提供了如下技术方案。
1.一种碳包覆镍钯合金纳米粒子的复合材料，该复合材料包含具有壳层和内核的核壳结构，所述壳层为石墨化碳层，所述内核为镍钯合金纳米粒子；所述复合材料中，镍与钯的质量比为3:1～100:1；以所述复合材料的质量为基准，镍和钯的总质量分数为1％～80％。
2.按照前述的复合材料；其中，所述镍与钯的质量比为4:1～100:1，优选为4:1～9:1。
3.按照前述任一的复合材料；其中，以所述复合材料为基准，镍和钯的总质量分数为30％～80％，优选为50％～78％。
4.按照前述任一的复合材料；其中，所述复合材料为介孔和/或大孔材料，介孔和/或大孔体积占总孔体积的50％以上。
5.按照前述任一的复合材料；其中，所述镍钯合金纳米粒子的粒径为1nm～50nm，优选为2nm～25nm，更优选为3nm～15nm。
6.按照前述任一的复合材料；其中，所述石墨化碳层的厚度为0.5nm～10nm，优选为0.5nm～5nm，更优选为1nm～5nm。
7.按照前述任一的复合材料；其中，所述复合材料的XRD谱图中，2θ在40.1°～44.5°范围内仅有一个衍射峰。
8.按照前述任一的复合材料；其中，所述复合材料的XRD谱图中，在2θ为24°至26°范围内存在衍射峰；和/或，所述复合材料的XRD谱图中，在2θ为43°至45°、50°至54°、75°至80°范围内存在衍射峰。
9.按照前述任一的复合材料；其中，所述复合材料的XRD谱图中，在40.0°±0.1°范围内没有衍射峰。
10.一种碳包覆镍钯合金纳米粒子的复合材料的制备方法，包括以下步骤：
S1在第一溶剂的存在下，将镍源、钯源与有机多元羧酸混合，得到前驱体溶液，然后除去所述第一溶剂，得到前驱体；
S2将所述前驱体在惰性气体中进行热解。
11.按照前述的制备方法；其中，所述第一溶剂为水和/或乙醇，优选为水。
12.按照前述任一的制备方法；其中，所述镍源为乙酸镍、碱式碳酸镍和碳酸镍中的一种或多种。
13.按照前述任一的制备方法；其中，所述钯源为乙酸钯，优选为乙酸钯的冰醋酸溶液。
14.按照前述任一的制备方法；其中，所述有机多元羧酸为柠檬酸、乙二胺四乙酸、2,5-吡啶二羧酸、苹果酸、酒石酸和对苯二甲酸中的一种或多种。
15.按照前述任一的制备方法；其中，以金属元素计，所述镍源与钯源的质量比为3:1～100:1，优选为4:1～100:1，更优选为4:1～9:1。
16.按照前述任一的制备方法；其中，镍源和钯源的总量与有机多元羧酸的摩尔比为0.1:1～3:1，优选为0.3:1～1.5:1，其中，镍源和钯源的总量以金属元素的总摩尔量计。
17.按照前述任一的制备方法；其中，S2中，热解温度为500℃～800℃，优选为500℃～700℃，更优选为550℃～650℃。
18.按照前述任一的制备方法；其中，包括在S2之后的酸处理步骤。
19.一种改性的碳包覆镍钯合金纳米粒子的复合材料；其中，包括1所述的复合材料和负载于其上的含硫化合物。
20.按照19所述的改性复合材料；其中，所述含硫化合物为硫脲。
21.按照19或20所述的改性复合材料；其中，元素分析的硫元素的质量分数为0.5％～5％。
22.一种改性的碳包覆镍钯合金纳米粒子的复合材料的制备方法，其包括：在1所述的复合材料上负载含硫化合物的步骤。
23.按照22所述的制备方法；其中，所述含硫化合物为硫脲。
24.按照22或23所述的制备方法；其中，相对于1所述的复合材料中1mol的钯元素，所述含硫化合物以硫元素计的用量为0.01mol～20mol。
25.10～18中任一所述的制备方法所制得的复合材料。
26.22～24中任一所述的制备方法所制得的改性复合材料。
27.在含硫化合物的存在下前述任一的复合材料或前述任一的改 性复合材料作为加氢催化剂用于催化加氢的应用。
28.按照27的应用；其中，氢气和/或加氢底物中含有含硫化合物。
29.前述任一的复合材料或前述任一的改性复合材料在催化加氢有机化合物中的硝基的应用。
30.一种对卤代硝基芳烃中的硝基进行选择性加氢的方法，包括以下步骤：在液相催化加氢的条件下，在含硫化合物的存在下，将氢气与卤代硝基芳烃与催化剂接触，进行液相催化加氢反应；所述的催化剂为1～9和25中任一所述的复合材料；所述的含硫化合物为硫氰酸盐和/或硫脲，所述含硫化合物与卤代硝基芳烃的质量比为1：100～1：10000。
31.按照30所述的方法，其中，所述含硫化合物与卤代硝基芳烃的质量比为1：100～1：150。
32.一种对卤代硝基芳烃中的硝基进行选择性加氢的方法，包括以下步骤：在液相催化加氢的条件下，将氢气与卤代硝基芳烃与催化剂接触，进行液相催化加氢反应；所述的催化剂为19～21和26中任一所述的复合材料。
33.按照30～32所述的对卤代硝基芳烃中的硝基进行选择性加氢的方法，其特征在于，进一步包括采用磁分离对复合材料或改性复合材料进行分离的步骤。
34.一种催化加氢脱除有机氯的方法，包括以下步骤：在液相催化加氢脱氯的反应条件下，将含氯的饱和或芳香有机化合物，与氢气和催化剂接触反应；所述催化剂为1～9和25中任一所述的复合材料。
35.按照33所述的脱氯方法，其特征在于，所述液相催化加氢脱氯的反应条件为：温度范围40-120℃，优选60-100℃，氢气压力范围0.1-3MPa，优选1-2MPa。
36.按照33所述的脱氯方法，其特征在于，所述含氯的芳香有机化合物为选自一氯代苯酚、二氯代苯酚、三氯代苯酚、氯代芳香烃、2,4-二氯苯氧乙酸和氯代硝基苯中的一种或几种。
37.按照33所述的脱氯方法，其特征在于，所述含氯的饱和有机化合物为选自氯代饱和脂肪烃中的一种或几种。
38.按照33所述的脱氯方法，其特征在于，所述方法中使用溶剂； 所述溶剂为选自异丙醇、乙醇、丙酮、四氢呋喃、环己烷和水中的一种或多种。
39.按照33所述的脱氯方法，其特征在于，催化剂与作为反应底物的含氯的饱和或芳香有机化合物的质量比为0.05-0.8:1，优选0.1-0.3：1。
40.按照33所述的脱氯方法，其特征在于，进一步包括采用磁分离对复合材料进行分离的步骤。
41.按照33所述的脱氯方法，其特征在于，所述复合材料中，镍与钯的质量比为3:1～10:1，优选为3:1～6:1。
42.按照33所述的脱氯方法，其特征在于，以所述复合材料为基准，镍和钯的总质量分数为20％～80％，优选为50％～80％。
与现有技术相比，本发明有以下有益技术效果。
本发明利用镍的促进碳石墨化能力，结合有机多元羧酸的特定络合作用和还原能力，由此，可以以简单方法将镍钯合金以纳米粒子的形式包覆在碳外壳之中，而且包覆比较严密。因此，在镍源化合物的基础上，进一步配合钯源化合物时，可以以简单方法得到一种碳包覆镍钯合金纳米粒子的复合材料，从而实现了对钯的有效包覆。该复合材料兼具纳米碳材料的稳定性和钯金属纳米粒子的催化特点。具体而言，该复合材料具有本征安全性，理论上不存在金属粒子聚结失活和流失的问题，也不存在金属活性成分中毒的问题，而且在加氢反应中表现出高于碳包覆镍纳米粒子复合材料的催化活性。
本发明还可以方便地根据需要对该复合材料进行改性，从而调变该复合材料的催化性质，进而使其适用于不同用途，例如可以对有机化合物中的硝基进行选择性加氢；对于有机化合物中的氯原子进行加氢脱除。其中，对于硝基进行选择性加氢时，不论是在反应过程中加入含硫化合物，还是预先在复合材料表面负载含硫化合物，均可实现对有机化合物中硝基进行高选择性加氢。对有机化合物进行加氢脱氯时，催化剂具有本征的抗氯中毒能力和抗活性金属流失能力，因此，能够表现出优异的催化效果。另一方面，催化活性组分为合金且钯含量较低，但仍具备钯的催化加氢脱氯能力；反应中不使用碱，仍具备很高的脱氯活性；溶剂含水或不含水时的脱氯活性都很高。
另外，由于本发明的复合材料、以及各类改性复合材料中存在镍， 因此，复合材料、改性复合材料中具有较强磁性，在作为催化剂参与的反应完毕后，可以采用磁分离，方便地回收作为催化剂的复合材料、改性复合材料。
本发明的其他特征和优点将在具体实施方式部分中详细说明。
附图说明
图1为按照制备例3制备的复合材料的球差电镜图片；图1(a)球差电镜照片，图1(b)明场像，图1(c)C、Pd、Ni元素的混合分布图，图1(d)C元素的分布图，图1(e)Pd元素的分布图；图1(f)Ni元素分布图。
图2为按照制备例3制备的复合材料的XRD图谱。
图3为按照制备例4制备的复合材料的XPS宽谱图。
图4为按照制备例1制备的复合材料在磁场存在下的形态照片。
具体实施方式
以下结合具体实施方式详述本发明，但需说明的是，本发明的保护范围不受这些具体实施方式和原理性解释的限制，而是由权利要求书来确定。
本发明中，除了明确说明的内容之外，未提到的任何事宜或事项均直接适用本领域已知的内容而无需进行任何改变。而且，本文描述的任何实施方式均可以与本文描述的一种或多种其他实施方式自由结合，由此形成的技术方案或技术思想均视为本发明原始公开或记载的一部分，而不应被视为是本文未曾披露或预期过的新内容，除非本领域技术人员认为该结合明显不合理。
本发明所公开的所有特征可以任意组合，这些组合应理解为本发明所公开或记载的内容，除非本领域技术人员认为该组合明显不合理，均应被视为被本发明所具体公开和记载。本说明书所公开的数值点，除特别指明外，不仅包括实施例中具体公开的数值点，还包括说明书中各数值范围的端点，这些数值点所任意组合的范围都应被视为本发明已公开或记载的范围。
本发明中的技术和科学术语，给出定义的以其定义为准，未给出定义的则按本领域的通常含义理解。
术语“石墨化碳层”是指在高分辨透射电镜下可明显观察到层状碳结构，而非无定型结构。
术语“介孔”定义为孔径在2nm～50nm范围的孔。孔径小于2nm的孔定义为微孔，大于50nm的孔定义为大孔。
术语“酸处理”是指在制备碳包覆镍钯合金纳米粒子的复合材料时对高温热解步骤后生成的产物在接近酸溶液沸腾温度下进行酸洗的操作。
术语“惰性气体”定义为对复合材料的催化加氢性能不构成可察觉影响的气体。例如包括但不限于，氮气、氦气、氩气等。
术语“可溶”是指在使用时的溶剂中可溶。
符号“PPMw”代表重量百万分比。
术语“任选”是指可以有或没有，如A和任选的B，是指“有A且没有B”或“同时有A和B”。
本发明的第一方面提供了一种碳包覆镍钯合金纳米粒子的复合材料，该复合材料含有具有壳层和内核的核壳结构，所述壳层为石墨化碳层，所述内核为镍钯合金纳米粒子；所述复合材料中，镍与钯的质量比为3:1～100:1；以所述复合材料的质量为基准，镍和钯的总质量分数为1％～80％。
根据第一方面的复合材料，其由镍、钯、碳和氧组成。应当理解到，本发明的复合材料主要由零价的镍、钯和碳组成，由于合成原料中的碳源含氧，不可避免地在复合材料的表层碳中会掺有少量氧；复合材料存放于空气中表面也会吸附氧，少量或微量的镍、钯可能以氧化态的形式存在，合成原料中的杂质也可能导致含有少量或微量的其他元素，但这些因素对复合材料的性能都没有明显影响；本发明认为没有必要对这些进行特定。
根据第一方面的复合材料，其中镍与钯的质量比为3:1～100:1，优选为4:1～100:1；如果需要相对更高的催化加氢活性，可将镍与钯的质量比进一步控制在4:1～9:1之间，还可以控制在3:1～10:1之间，或者3:1～6:1之间。在上述比例范围内，复合材料的XRD图谱中只有fccNiPd合金的衍射峰。若钯含量若过高则会在XRD图谱中出现单质钯的特征峰，并且这些单质钯未被碳严密包覆，不具有抵抗聚结、抵抗中毒失活的能力。
根据第一方面的复合材料，以所述复合材料为基准，镍和钯的总质量分数为1％～80％，优选为20％～80％，进一步优选为30％～80％，进一步优选为50％～80％，更优选为50％～78％。本发明已发现，即使在镍中掺杂1％左右的钯，也明显提高了所述复合材料的催化加氢能力。在本发明的一些实施方式中，即使进行了酸处理，所述复合材料中的镍钯总质量分数仍可达到75％左右。
根据第一方面的复合材料，其所述壳结构由石墨化碳层构成，换言之，本发明的壳结构中，不掺杂其他元素。但是，需要说明的是，本发明的复合材料中，可能含有微量的无定形碳，该无定形碳只是作为杂质而存在，本发明无意对其进行限定。
根据第一方面的复合材料，其为介孔和/或大孔材料，介孔和/或大孔体积占总孔体积的50％以上。一些实施方式中，所述复合材料具有介孔结构或介孔和大孔结构。本领域熟知，孔结构为催化剂的宏观性质。
根据第一方面的复合材料，其比表面积为50m2/g～500m2/g，优选100m2/g～300m2/g。
根据第一方面的复合材料，在透射电镜观测下，所述镍钯合金纳米粒子的粒径为1nm～50nm，一般为2nm～25nm之间，优选为3nm～15nm。一些实施方式中，镍钯合金纳米粒子的粒径分布较窄，基本在4nm～10nm之间。
根据第一方面的复合材料，在透射电镜观测下，所述石墨化碳层的厚度为0.5nm～10nm，优选为0.5nm～5nm，一般在1nm～5nm之间。
根据第一方面的复合材料，所述核壳结构呈球形或类球形。
根据第一方面的复合材料，一些实施方式的XRD谱图中2θ在40.1°～44.5°范围内仅有一个衍射峰。
根据第一方面的复合材料，所述复合材料的XRD谱图中，在2θ为24°至26°范围内存在衍射峰；和/或，所述复合材料的XRD谱图中，在2θ为43°至45°、50°至54°、75°至80°范围内存在衍射峰。
根据第一方面的复合材料，其中，所述复合材料的XRD谱图中，在40.0°±0.1°范围内没有衍射峰。
本发明的第二方面提供了一种改性碳包覆镍钯合金纳米粒子的复合材料(以下，有时也称为改性复合材料)，其包括第一方面的复合材料 和负载于其上的含硫化合物。
根据第二方面的改性复合材料，其由第一方面的复合材料和负载于其上的含硫化合物组成。
根据第二方面的改性复合材料，所述含硫化合物的分子量一般小于200。所述含硫化合物既可以是有机硫化合物，也可以是无机硫化合物；所述有机硫化合物中，碳硫键既可以为双键，也可以为单键。所述含硫化合物优选为硫脲。
以第二方面的改性复合材料为基准，通过元素分析得到的硫的质量分数可以为0.1％～10％，优选为0.5％～5％，更优选为0.8％～1.8％。
本发明的第三方面提供了第一方面复合材料的制备方法，包括以下步骤：
S1在第一溶剂的存在下，将镍源、钯源与有机多元羧酸混合，得到前驱体溶液，然后除去所述第一溶剂，得到前驱体；
S2将所述前驱体在惰性气体中进行热解。
根据第三方面的制备方法，所述第一溶剂为水和/或乙醇，优选为水。
根据第三方面的制备方法，所述镍源为可溶性镍盐，可以为乙酸镍、碱式碳酸镍和碳酸镍中的一种或多种。
根据第三方面的制备方法，所述钯源为含钯溶液，可以为乙酸钯的溶液，优选为乙酸钯的冰醋酸溶液。
根据第三方面的制备方法，所述有机多元羧酸为复合材料提供碳源，并且发挥络合剂的作用。优选为分子中同时含有羟基的有机多元羧酸。所述有机多元羧酸可以为柠檬酸、乙二胺四乙酸、2,5-吡啶二羧酸、酒石酸或对苯二甲酸中的一种或多种，优选为柠檬酸。
根据第三方面的制备方法，以金属元素计，所述镍源与钯源的质量比为3:1～100:1，优选为4:1～100:1，更优选为4:1～9:1。
根据第三方面的制备方法，S1中，镍源和钯源的总量与有机多元羧酸的摩尔比为0.1:1～3:1，优选为0.3:1～1.5:1，其中，镍源和钯源的总量以金属元素的总摩尔量计。
根据第三方面的制备方法，S1中，所述前驱体溶液可以按以下方法制得：将镍源、钯源和作为碳源的有机多元羧酸加入到水和/或乙醇中，在40℃～100℃下搅拌8h～16h，优选在50℃～90℃下搅拌10h～ 12h；其中，钯源按每100mL冰醋酸溶解有以钯计为0.5g～1.1g的乙酸钯的冰醋酸溶液的形式提供，镍源以乙酸镍(可以含或不含结晶水)的形式提供。此时，调节镍源的用量以使得以金属元素计，镍源与钯源的质量比为3:1～100:1，优选为4:1～100:1，更优选为4:1～9:1；调节多元羧酸的用量，以使得镍源和钯源的总量与有机多元羧酸的摩尔比为0.1:1～3:1，优选为0.3:1～1.5:1。
根据第三方面的制备方法，S1中，优选采用直接蒸发的方式除去所述前驱体溶液中的第一溶剂，例如，可以在旋转蒸发仪上将所述前驱体溶液中的第一溶剂蒸干和/或在烘箱中干燥。
根据第三方面的制备方法，S2中满足以下条件中的至少一个：热解温度为500℃～800℃，优选为500℃～700℃，更优选为550℃～650℃；和/或，热解时间为1h～4h，优选为1.5h～3h；和/或，升温速率为1℃/min～10℃/min，优选为2℃/min～5℃/min。
根据第三方面的制备方法，S2中，所述惰性气体可以为氮气、氩气或氦气。
根据第三方面的制备方法，还包括在S2之后的任选的酸处理步骤。本发明对酸处理所使用的酸种类、用量及处理时间没有限制，本领域技术人员可根据现有知识和/或简单试验选择。一般使用非氧化性强酸进行酸处理，如盐酸或硫酸。本发明的一些实施方式中使用了盐酸，浓度可以为0.5mol/L～2mol/L，温度可以为60℃～100℃，可以接近酸溶液的沸腾温度，时间可以为3h～24h，还可以为3h～10h。
根据第三方面的制备方法，还包括对产品进行酸洗的后处理步骤，如过滤、洗涤、干燥等。
本发明的第四方面提供了第二方面的改性复合材料的制备方法(以下，有时也称为“改性复合材料的制备方法”)，其包括使第一方面的复合材料与含硫化合物接触的步骤。
通过本发明的改性复合材料的制备方法，得到的改性复合材料中，第一方面的复合材料上负载有含硫化合物。
根据第四方面的改性复合材料的制备方法，对含硫化合物的接触方式没有特别的限制，本领域技术人员可采用任何现有已知的方式，使第一方面的复合材料与含硫化合物接触，以将含硫化合物负载于第一方面的复合材料上。一种优选的方式是，将第一方面的复合材料先分 散于第二溶剂中，将含硫化合物溶解于第三溶剂，制成溶液；然后将两种液体混合；为使二者的接触充分、均匀，可以采用机械搅拌混合，也可以采用超声混合；或者将二者结合，先超声混合，然后再机械搅拌混合。接触时间可以为12h～24h。
根据第四方面的改性复合材料的制备方法，所述的第二溶剂为水和/或醇类溶剂，优选为水。
根据第四方面的改性复合材料的制备方法，所述的第三溶剂为水和/或醇类溶剂，优选为水。
一些实施方式中，含硫化合物为硫脲。一些实施方式中，第一溶剂和第二溶剂优选为水。一些实施方式中，超声时间为0.5h～3h，机械搅拌的时间为2h～24h，负载温度为25℃～90℃。
根据第四方面的改性复合材料的制备方法，所述含硫化合物的种类和用量可在较大范围内变化。本发明已发现，采用含硫化合物处理第一方面的复合材料后，可以明显影响催化加氢反应时的选择性，本领域技术人员可根据实际需要，通过试验选择恰当的含硫化合物并确定其用量。但不同的小分子含硫化合物对复合材料的影响是不同的，比如选用硫脲时在对卤代硝基苯进行催化加氢反应中，选择性可达100％。
根据第四方面的改性复合材料的制备方法，可以采用浸渍的方法负载含硫化合物。为了有更高的选择性，相对于第一方面的复合材料中1mol的钯元素，所述含硫化合物以硫元素计的用量可以为0.01mol～20mol，优选为0.3mol～5mol。
根据第四方面的制备方法，还包括对完成负载后产品进行后处理的步骤，如过滤、洗涤、干燥等。
本发明的第五方面提供了前述任一方面的制备方法制得的碳包覆镍钯合金纳米粒子的复合材料。
本发明的第六方面提供了前述任一方面的改性复合材料的制备方法制得的改性的碳包覆镍钯合金纳米粒子的复合材料。
本发明的第七方面提供了前述任一方面的复合材料、前述任一方面的改性复合材料作为加氢催化剂在催化加氢体系含硫时的应用。
根据第七方面的应用，氢气和/或加氢底物中可以含硫。化石燃料制取氢气是石油化工领域获得工业氢的主要方式，这类原料在制氢过 程中不可避免的会产生含硫化合物，尽管变压吸附(PSA)技术可以使氢气纯度达到99.9％以上，但氢气中仍有含硫化合物；某些反应底物本身就含硫，如硫代硝基芳烃等；反应底物中也可能存在含硫杂质，这些含硫化合物对加氢催化剂的影响仍然不能忽视。本发明已经发现，即使用浓度很高、毒性很大的硫脲处理本发明的复合材料，其仍具备很高的催化加氢活性，因此将其作为加氢催化剂用于这些含硫化合物存在条件下的催化加氢体系时有独特的优势。
根据第七方面的应用，加氢底物中含有硝基、碳碳双键、碳碳三键、酮基、醛基和芳环中的一种或几种官能团。现有技术已经实现用碳包覆镍纳米粒子复合材料或者改性复合材料对上述官能团的加氢，本发明的复合材料、改性复合材料比碳包覆镍纳米粒子复合材料的催化加氢活性更高，因此同样可以对有机化合物中含有的上述官能团进行催化加氢。
本发明的第八方面提供了对硫代硝基芳烃的硝基进行选择性加氢的方法，包括以下步骤：在液相催化加氢的条件下，将氢气与硫代硝基芳烃与催化剂接触，进行液相催化加氢反应；所述的催化剂为第一、第五方面的复合材料或者第二、第六方面的改性复合材料。
根据第八方面的应用，所述硫代硝基芳烃具有如式(I)所示结构：
其中，X选自硫、砜基中的一种或多种，R1选自氢、C1-C6烃基、C1-C3卤代烃基、C1-C3羟基烃基、巯基、C6-C10芳基和C6-C10芳基硫基中的一种或多种，R2选自氢、C1-C6烃基、羟基、羧基、卤素、氨基、巯基、C6-C10芳基、C6-C10芳基硫基和硝基中的一种或多种，所述芳基未被取代或者被下述基团中的一种或多种取代：硝基、C1-C6烃基、羟基、羧基、卤素、氨基或氨基。
在本发明的一个实施方式中，所述烃基可以为烷基、烯基或者炔基，优选为烷基。本发明的一个实施方式中，所述芳基可以列举苯基、萘基。本发明的一个实施方式中，所述卤素和所述卤代中的卤素可以为 氟、氯、溴、碘。
常见的硫代硝基芳烃有4-硝基茴香硫醚、2-硝基二苯硫醚、4-硝基苯硫酚、3,3’-二硝基二苯砜和4,4’-二硝基二苯砜。现有技术已经实现用碳包覆镍纳米粒子复合材料对上述化合物的加氢，本发明的复合材料、改性复合材料比碳包覆镍纳米粒子复合材料的催化加氢活性更高，因此也能对上述有机化合物进行催化加氢。
本发明的第九方面提供了一种对卤代硝基芳烃中的硝基进行选择性加氢的方法，包括以下步骤：在液相催化加氢的条件下，在含硫化合物的存在下，将氢气与卤代硝基芳烃与催化剂接触，进行液相催化加氢反应；所述的催化剂为本发明第一或者第五方面的复合材料；所述的含硫化合物为硫氰酸盐和/或硫脲，所述含硫化合物与卤代硝基芳烃的质量比为1：100～1：10000。
本发明已发现，加入含硫化合物后，可以明显影响催化加氢反应时的选择性，本领域技术人员可根据实际需要，通过试验选择恰当的含硫化合物并确定其用量。根据第九方面的方法，一般含硫化合物的分子量在200以下，此时操作更方便；一般用量范围比较宽，使控制更容易。但不同的小分子含硫化合物对反应选择性的影响是不同的，比如对氯代硝基苯选择性加氢制造氯代苯胺而言，选用硫化钠的选择性只有70％至80％，选用硫氰酸盐的选择性在98％以上，而选用硫脲的选择性可达100％。
根据第九方面的方法，所述硫氰酸盐通常为硫氰酸钾和/或硫氰酸钠。
根据第九方面的方法，所述含硫化合物与卤代硝基芳烃的质量比优选为1：100～1：150。
根据第九方面的方法，所述催化剂与卤代硝基芳烃的质量比为1：1～1：15，优选为1：1～1：7。
根据第九方面的方法，所述液相催化加氢的条件为：温度为20℃～100℃，优选为40℃～60℃；和/或，氢气压力为0.5MPa～4MPa，优选为0.8MPa～2MPa。
根据第九方面的方法，所述液相加氢反应使用溶剂，所述溶剂选自异丙醇、乙醇、丙酮和水中的一种或多种，优选为异丙醇和/或水，更优选为异丙醇与水的体积比为10：1～5：1的混合溶剂。
根据第九方面的方法，所述卤代硝基芳烃为氯代硝基苯，优选为间氯硝基苯或对氯硝基苯。
本发明的第十方面提供了另一种对卤代硝基芳烃中的硝基进行选择性加氢的方法，包括以下步骤：在液相催化加氢的条件下，将氢气与卤代硝基芳烃与催化剂接触，进行液相催化加氢反应；所述的催化剂为本发明第二或第六方面的改性复合材料。
根据第十方面的方法，所述催化剂与卤代硝基芳烃的质量比为1：1～1：15，优选为1：1～1：7。
根据第十方面的方法，所述液相催化加氢的条件为：温度为20℃～100℃，优选为40℃～60℃；和/或，氢气压力为0.5MPa～4MPa，优选为0.8MPa～2MPa。
根据第十方面的方法，所述液相加氢反应使用溶剂，所述溶剂选自异丙醇、乙醇、丙酮和水中的一种或多种，优选为异丙醇和/或水。
根据第十方面的方法，所述卤代硝基芳烃为氯代硝基苯，优选为间氯硝基苯或对氯硝基苯。
本发明的第十一方面提供了一种催化加氢脱除有机氯的方法，包括：在液相催化加氢脱氯的反应条件下，将含氯的饱和或芳香有机化合物，与氢气和催化剂接触反应；所述催化剂为本发明第一或者第五方面的复合材料。
根据第十一方面的方法，所述复合材料中，镍与钯的质量比为3:1～10:1，优选为3:1～8:1，更优选为3:1～6:1。
根据第十一方面的方法，所述复合材料中，以所述复合材料为基准，镍和钯的总质量分数为20％～80％，优选为30％～80％，更优选为50％～80％。
根据第十一方面的方法，所述液相催化加氢脱氯的反应条件为：温度范围40-120℃，优选60-100℃，氢气压力范围0.1-3MPa，优选1-2MPa。
根据第十一方面的方法，所述含氯的芳香有机化合物优选氯原子直接连接在芳环上，更优选选自一氯代苯酚、二氯代苯酚、三氯代苯酚、氯代芳香烃、2,4-二氯苯氧乙酸和氯代硝基苯中的一种或几种。
根据第十一方面的方法，所述含氯的饱和有机化合物为选自氯代饱和脂肪烃中的一种或几种。
根据第十一方面的方法，所述方法中可以使用或不使用溶剂。是否 使用溶剂取决于反应底物本身是否在加氢条件下为适宜的液态，以及本领域技术人员的需要；选用何种溶剂取决于保证反应底物能溶解，这些都是本领域已知的。如果用于处理废水中溶解的有机氯化物，则水本身即为溶剂。另外，可以用于本发明第十一方面的溶剂包括但不限于：异丙醇、乙醇、丙酮、四氢呋喃、环己烷和水中的一种或多种。如果有机氯化物溶于醇但不溶于水，则优选采用醇和水的混合溶剂，醇与水的体积比优选为10：1～5：1。
根据第十一方面的方法，催化剂与作为反应底物的含氯的饱和或芳香有机化合物的比例以质量比计为0.05～0.8：1，优选为0.1～0.3：1。
根据第十一方面的方法，为了保证脱氯效率，反应体系中不存在含硫化合物。
根据第十一方面的方法，所述脱氯方法可用于污水脱氯处理、原油脱氯预处理、有机副产物脱氯回收和有机合成等领域。
由于本发明的复合材料、改性复合材料中具有较强磁性，因此在本发明的上述各方法中，在反应完成后，可以采用磁分离，方便地回收作为催化剂的复合材料、改性复合材料。
分析和表征
通过高分辨透射电镜(HRTEM，日本电子株式会社，JEM-2100)表征材料的表面形貌，加速电压为200kV。
通过球差电镜(STEM)表征材料中的各元素分布。所采用球差电镜的型号为JEM-ARM200F(日本电子株式会社)，测试条件为：加速电压为200kV。
通过XRD获得材料的成分、材料内部原子或分子的结构或形态等信息。所采用的XRD衍射仪为购自荷兰PA Nalytical的型号为X’Pert Pro的X射线衍射仪，测试条件为：Cu靶，Kα射线，管电压为40kV，管电流为40mA，2θ扫描范围为5°至80°。
通过X射线光电子能谱分析仪(XPS)检测材料表面的元素。所采用X射线光电子能谱分析仪为VG Scientifc公司生产配备有Avantage V5.926软件的ESCALab220i-XL型射线电子能谱仪，X射线光电子能谱分析测试条件为：激发源为单色化A1KαX射线，功率为330W，分析测试时基础真空为3×10-9mbar。
通过Brunauer-Emmett-Taller法(BET，Quantachrome AS-6B型分析 仪)测定材料的比表面积和孔径分布。
碳、氢、氧、氮、硫元素的含量测试在Elementar Vario EL Cube元素分析仪上进行，具体操作方法如下：样品在锡杯中称量5mg左右，放入自动进样盘，通过球阀进入燃烧管燃烧，燃烧温度1000℃(为排除进样时大气干扰，采用氦气吹扫)，样品中的C、H、N、S分别转化为二氧化碳、水、氮气、二氧化硫。混合气体通过色谱柱进行分离，最后通过热导池检测。氧元素测定时，样品在装有碳粉的高温裂解管中裂解，样品中的氧转化为一氧化碳，载气携带裂解产物进入串联的洗涤器中，以除去酸气和水蒸气，最后进入红外检测器进行检测。
镍、钯元素的含量测定采用电感耦合等离子体发射光谱法(ICP-OES)，具体方法如下：(1)硝解：量取催化剂样品10mg放入烧瓶里，加入新鲜配置的16mL王水，加入磁力搅拌子，将烧瓶放入油浴锅中，120℃冷凝回流12h，冷却至室温后，玻璃注射器吸取溶液，用孔径0.22μm的一次性滤头过滤，滤液加入500mL容量瓶中，超纯水定容。(2)含量测试：取硝解定容后的溶液10mL，采用仪器Agilent5110进行金属含量测试。
如无特殊说明，本发明所用试剂均为分析纯，所用试剂均为市售可得。
制备例1～5用于说明本发明的复合材料及其制备方法
制备例1
1)称取0.040g乙酸钯并量取3mL冰醋酸。加入到170mL去离子水中，在50℃下搅拌溶解。按照镍源与钯源的质量比为100：1(以金属元素计)，镍钯总摩尔量与络合剂的摩尔比为1：1，称取一水柠檬酸和四水乙酸镍加入到上述溶液中，在70℃下搅拌得到均相溶液，并继续加热蒸干，将固体研磨后得到前驱体。
2)将步骤1)得到的前驱体置于瓷舟内，然后将瓷舟置于管式炉的恒温区，通入氮气，流量150mL/min，并以2.5℃/min的速率升温至600℃，恒温2h后停止加热，在氮气气氛下冷却至室温，得到热解产物。
3)将步骤2)得到热解产物加入200mL1mol/L HCl溶液中，在90℃下搅拌并回流4h后将溶液进行抽滤，并用去离子水洗至中性后将粉末置于100℃烘箱干燥2h，得到碳包覆镍钯纳米复合材料。
制备例2
按照制备例1的方法，不同的是，步骤1)中，称取0.657g乙酸钯并量取35mL冰醋酸。加入到170mL去离子水中，在50℃下搅拌溶解。按照镍源与钯源的质量比为17：3(以金属元素计)，镍钯总摩尔量与络合剂的摩尔比为1：1，称取一水柠檬酸和四水乙酸镍加入到上述溶液中，在70℃下搅拌得到均相溶液，并继续加热蒸干，将固体研磨后得到前驱体，其余均与制备例1相同，得到碳包覆镍钯纳米复合材料。
制备例3
按照制备例1的方法，不同的是，步骤1)中，称取0.943g乙酸钯并量取60mL冰醋酸。加入到170mL去离子水中，在50℃下搅拌溶解。按照镍源与钯源的质量比为4：1(以金属元素计)，镍钯总摩尔量与络合剂的摩尔比为1：1，称取一水柠檬酸和四水乙酸镍加入到上述溶液中，在70℃下搅拌得到均相溶液，并继续加热蒸干，将固体研磨后得到前驱体，其余均与制备例1相同，得到碳包覆镍钯纳米复合材料。
制备例4
本制备例用于说明含硫的碳包覆镍钯纳米复合材料。
称取0.5g按照制备例3方法获得的复合材料，加入10mL去离子水中，超声1h使纳米材料分散均匀；称取0.036g硫脲加入10mL去离子水中，超声1h使硫脲完全溶解；将上述两种液体混合后超声1h，然后进行机械搅拌12h，转速为800rpm，抽滤，用去离子水洗涤5次后冷冻干燥，得到负载有含硫化合物(硫脲)的碳包覆镍钯纳米复合材料(改性复合材料)，元素分析测得硫元素的质量百分含量为1.67％，BET测得材料的比表面积为145.0m2/g。
制备例5
1)称取0.411g乙酸钯并量取30mL冰醋酸，加入到170mL去离子水中，在50℃下搅拌溶解。按照镍源与钯源的质量比为9：1(以金属元素计)，镍钯总摩尔量与络合剂的摩尔比为1：1，称取一水柠檬酸和四水乙酸镍加入到上述溶液中，在70℃下搅拌得到均相溶液，并继续加热蒸干，将固体研磨后得到前驱体。
2)将步骤1)得到的前驱体置于瓷舟内，然后将瓷舟置于管式炉的恒温区，通入氮气，流量150mL/min，并以2.5℃/min的速率升温至600℃，恒温2h后停止加热，在氮气气氛下冷却至室温，得到热解产物。
3)将步骤2)得到热解产物加入200mL 1mol/L HCl溶液中，在90℃ 下搅拌并回流4h后将溶液进行抽滤，并用去离子水洗至中性后将粉末置于100℃烘箱干燥2h，得到碳包覆镍钯合金纳米复合材料。
实施例1～3用于说明本发明的复合材料作为催化剂催化对氯硝基苯选择性加氢合成对氯苯胺的方法
分别将100mg按照制备例1～3方法制得的碳包覆镍钯纳米复合材料、315mg对氯硝基苯、2.4mg硫脲、27mL异丙醇、3mL水加入反应釜中，通入H2置换反应釜4次后，低压下搅拌升温，升温至预定反应温度60℃，再次通入H2使反应釜内压力为1.0MPa，持续反应至压力10分钟不变化，冷却至室温后排压，打开反应釜取出产物进行色谱分析。通过以下公式计算反应物转化率及目标产物选择性：
转化率＝已反应的反应物质量/反应物加入量×100％
选择性＝目标产物质量/反应生成物质量×100％
实施例1反应至压力10分钟无变化的时长为180分钟，产物经分析后，得到对氯硝基苯转化率为100％，对氯苯胺选择性为100％。
实施例2反应至压力10分钟无变化的时长为77分钟，产物经分析后，得到对氯硝基苯转化率为100％，对氯苯胺选择性为100％。
实施例3反应至压力10分钟无变化的时长为50分钟，产物经分析后，得到对氯硝基苯转化率为100％，对氯苯胺选择性为100％。
实施例4
按照实施例3的方法，不同的是，将硫脲替换为硫氰酸钾，其余均与实施例3相同，在同样的条件下催化对氯硝基苯加氢反应，对氯硝基苯转化率为100％，对氯苯胺选择性为98.84％。
实施例5
按照实施例1的方法，不同的是，不加入硫脲，其余均与实施例1相同，在同样的条件下催化对氯硝基苯加氢反应，对氯硝基苯转化率为100％，对氯苯胺选择性为65.5％，其余为苯胺。
实施例6
按照实施例3的方法，不同的是，催化剂为制备例4的改性复合材料，用量为100mg，不加入硫脲，对硝基氯苯为157.5mg，其余均与实施例3相同，在同样的条件下催化对氯硝基苯加氢反应，对氯硝基苯转化率为100％，对氯苯胺选择性为100％。
对比例1
按照实施例1的方法，不同的是，将催化剂替换为商用钯碳催化剂(10wt％Pd，含水55％)，其余均与实施例1相同，进行同样条件的催化加氢反应，对氯硝基苯转化率为0％。可见传统的负载型Pd催化剂在含硫毒物存在的情况下完全丧失催化活性，不具备抗硫中毒的能力。
对比例2
按照实施例1的方法，不同的是，将催化剂替换为商用钯碳催化剂(10wt％Pd，含水55％)，且不加入硫脲，其余均与实施例1相同，在同样的条件下催化对氯硝基苯加氢反应，对氯硝基苯转化率为100％，产物中对氯苯胺含量≈0。可见传统的负载型Pd催化剂对于对氯苯胺的选择性很差。
表1本发明复合材料中的镍、钯质量分数及镍钯质量比
由表1可见，尽管进行了酸洗且镍与钯的质量比在较大范围内变化，制备例的复合材料中金属含量均为75％左右，即本发明的复合材料中金属含量很高，并且具备抗酸腐蚀能力，可避免酸性环境下应用时活性金属的流失。
由图1的球差电镜各图片可见，按照制备例3制备的复合材料中，金属纳米粒子由镍元素和钯元素在原子尺度混合而成，本发明的其他制备例也有相同的特征，即本发明的复合材料中金属纳米粒子为镍钯合金；本发明的其他制备例也有相同的特征。由图1中左上角的图片可见，金属纳米粒子粒径在2nm～25nm之间，石墨化碳层的厚度在1nm～5nm之间，碳包覆镍钯纳米粒子核壳结构为球形或类球形；本发明的其他制备例也有相同的特征。
由图2的XRD图谱可见，按照制备例3制备的复合材料只有fcc NiPd合金的衍射峰，没有单质镍和单质钯的衍射峰，本发明的其他制备例也有相同的特征，即本发明的复合材料中金属纳米粒子为镍钯合 金。
由图3的XPS谱图可见，按照制备例4制备的改性复合材料的表层有碳、氧、镍、钯、硫和氮元素。
由图4的图片可见，按照制备例1制备的复合材料在磁场作用下，被吸引到磁铁一侧的管壁。当撤去磁铁，复合材料在重力作用下平铺管内。本发明的其他制备例也有相同的特征，即本发明的复合材料具有较强的铁磁性，并有很好的流动性。
由实施例5可知，尽管在金属纳米粒子中掺入很少量的钯，但可以脱掉约35％的氯，表明复合材料的催化加氢能力明显增加，而金属纳米粒子仅为单质镍时基本没有加氢脱氯能力。
由对比例2可知，商用钯碳催化剂的加氢活性很高，在催化对氯硝基苯加氢时几乎将氯全部脱除。由对比例1可知，商用钯碳催化剂不具有抗硫毒化能力，加入约80PPMw的硫化物即可使之失去全部活性。
由实施例1～4可知，在反应体系中加入微量硫化物时，本发明的复合材料表现出良好的抗硫毒化能力，在催化对氯硝基苯加氢时保持很高的催化活性，同时具备高选择性的催化加氢能力；即采用本发明的复合材料可以高活性、高选择性地催化卤代硝基芳烃加氢制造卤代芳胺。
由实施例6可知，即使在制造改性复合材料的过程中，用高浓度的硫化物处理，本发明的改性复合材料具备高活性催化加氢能力，表明本发明的复合材料具有极强的抗硫毒化能力，并且处理后的复合材料，不需要在反应体系中再加入硫化物，就可高选择性地催化对氯硝基苯选择性加氢制造对氯苯胺；即采用本发明的经含硫化合物处理的改性复合材料可直接高活性、高选择性地催化卤代硝基芳烃加氢制造卤代芳胺，避免有毒物质混入加氢产品。
实施例7～8说明以本发明的复合材料为催化剂的催化加氢脱氯方法
分别将100mg按照制备例5和制备例3方法制得的碳包覆镍钯合金纳米复合材料、315mg对氯硝基苯、27mL异丙醇、3mL水加入反应釜中，通入H2置换反应釜4次后，低压下搅拌升温，升温至预定反应温度60℃，再次通入H2使反应釜内压力为1.0MPa，持续反应至压力10分钟不变化，冷却至室温后排压，打开反应釜取出产物进行色谱 分析。
实施例7的产物经分析后，对氯硝基苯转化率为100％，脱氯率(也即苯胺产率)为93.0％。
实施例8的产物经分析后，对氯硝基苯转化率为100％，脱氯率(也即苯胺产率)为97.9％。
实施例9
将100mg制备例3的复合材料、129mg4-氯苯酚、30ml乙醇加入反应釜中，通入H2置换反应釜4次后，低压下搅拌升温，升温至预定反应温度80℃，再次通入H2使反应釜内压力为1.0MPa，持续反应至压力10分钟不变化(约60min)，冷却至室温后排压，打开反应釜取出产物进行色谱分析。结果表明，4-氯苯酚转化率为100％，脱氯率为100％。
由实施例7～9可知，尽管制备例的复合材料用盐酸在较高温度下进行了长时间酸洗，但仍具备很高的催化加氢脱氯能力，说明本发明的复合材料具备良好的抗氯毒化能力。
由实施例9可知，尽管仅使用有机溶剂，但本发明的方法仍然具备很高的催化加氢脱氯能力。

Claims (17)

  1. 一种碳包覆镍钯合金纳米粒子的复合材料，该复合材料包含具有壳层和内核的核壳结构，所述壳层为石墨化碳层，所述内核为镍钯合金纳米粒子；所述复合材料中，镍与钯的质量比为3:1～100:1，优选4:1～100:1，进一步优选4:1～9:1，更优选；以所述复合材料的质量为基准，镍和钯的总质量分数为1％～80％，优选为30％～80％，更优选为50％～78％。
  2. 按照权利要求1所述的复合材料；其特征在于，其中，
    所述镍钯合金纳米粒子的粒径为1nm～50nm，优选为2nm～25nm，更优选为3nm～15nm，和/或
    所述石墨化碳层的厚度为0.5nm～10nm，优选为0.5nm～5nm，更优选为1nm～5nm，和/或
    所述复合材料为介孔和/或大孔材料，介孔和/或大孔体积占总孔体积的50％以上。
  3. 按照权利要求1所述的复合材料；其特征在于，所述复合材料的XRD谱图中：
    2θ在40.1°～44.5°范围内仅有一个衍射峰；和/或
    在2θ为24°至26°范围内存在衍射峰；和/或，
    在2θ为43°至45°、50°至54°、75°至80°范围内存在衍射峰；和/或
    在40.0°±0.1°范围内没有衍射峰。
  4. 一种碳包覆镍钯合金纳米粒子的复合材料的制备方法，包括以下步骤：
    S1在第一溶剂的存在下，将镍源、钯源与有机多元羧酸混合，得到前驱体溶液，然后除去所述第一溶剂，得到前驱体；
    S2将所述前驱体在惰性气体中进行热解。
  5. 按权利要求4所述的制备方法，其特征在于，其中，
    所述第一溶剂为水和/或乙醇，优选为水；和/或
    所述镍源为乙酸镍、碱式碳酸镍和碳酸镍中的一种或多种；和/或
    所述钯源为乙酸钯，优选为乙酸钯的冰醋酸溶液；和/或
    所述有机多元羧酸为柠檬酸、乙二胺四乙酸、2,5-吡啶二羧酸、苹 果酸、酒石酸和对苯二甲酸中的一种或多种，优选为柠檬酸；和/或
    以金属元素计，所述镍源与钯源的质量比为3:1～100:1，优选为4:1～100:1，更优选为4:1～9:1；和/或
    镍源和钯源的总量与有机多元羧酸的摩尔比为0.1:1～3:1，优选为0.3:1～1.5:1，其中，镍源和钯源的总量以金属元素的总摩尔量计；和/或
    S2中，热解温度为500℃～800℃，优选为500℃～700℃，更优选为550℃～650℃。
  6. 按权利要求4所述的制备方法，其特征在于，包括在S2之后的酸处理步骤。
  7. 一种改性的碳包覆镍钯合金纳米粒子的复合材料，其特征在于，包括权利要求1所述的复合材料和负载于其上的含硫化合物。
  8. 按照权利要求7所述的改性的碳包覆镍钯合金纳米粒子的复合材料，其特征在于，其中，
    硫元素的质量分数为0.1％～10％，优选为0.5％～5％，更优选为0.8％～1.8％；和/或
    所述含硫化合物为硫脲。
  9. 一种改性的碳包覆镍钯合金纳米粒子的复合材料的制备方法，包括：使权利要求1所述的复合材料与含硫化合物接触的步骤。
  10. 按照权利要求9所述的制备方法，其特征在于，其中，
    相对于权利要求1所述的复合材料中1mol的钯元素，所述含硫化合物以硫元素计的用量为0.01mol～20mol，优选为0.3mol～5mol；和/或
    所述含硫化合物为硫脲；和/或
    所述接触以浸渍方式进行。
  11. 一种对卤代硝基芳烃中的硝基进行选择性加氢的方法，包括以下的步骤：在液相催化加氢的条件下，在含硫化合物的存在下，将氢气与卤代硝基芳烃与催化剂接触，进行液相催化加氢反应；所述的催化剂为权利要求1所述的复合材料；优选所述的含硫化合物为硫氰酸盐和/或硫脲，优选所述含硫化合物与卤代硝基芳烃的质量比为1：100～1：10000，更优选质量比为1：100～1：150。
  12. 一种对卤代硝基芳烃中的硝基进行选择性加氢的方法，包括以 下的步骤：在液相催化加氢的条件下，将氢气与卤代硝基芳烃与催化剂接触，进行液相催化加氢反应；所述的催化剂为权利要求7所述的改性的碳包覆镍钯合金纳米粒子的复合材料。
  13. 一种对硫代硝基芳烃中的进行选择性加氢硝基的方法，包括以下的步骤：在液相催化加氢的条件下，将氢气与硫代硝基芳烃与催化剂接触，进行液相催化加氢反应；所述的催化剂为权利要求1所述的复合材料，优选所述硫代硝基芳烃为选自4-硝基茴香硫醚、2-硝基二苯硫醚、4-硝基苯硫酚、3,3'-二硝基二苯砜和4,4'-二硝基二苯砜中的至少一种。
  14. 一种催化加氢脱除有机氯的方法，包括以下的步骤：在液相催化加氢脱氯的反应条件下，将含氯的饱和或芳香有机化合物，与氢气和催化剂接触反应；所述催化剂为权利要求1所述的复合材料。
  15. 根据权利要求14所述的方法，其中，
    所述液相催化加氢脱氯的反应条件为：温度范围40-120℃，优选60-100℃，氢气压力范围0.1-3MPa，优选1-2MPa；和/或
    所述含氯的芳香有机化合物选自一氯代苯酚、二氯代苯酚、三氯代苯酚、氯代芳香烃、2,4-二氯苯氧乙酸和氯代硝基苯中的一种或几种；和/或
    所述含氯的饱和有机化合物为选自氯代饱和脂肪烃中的一种或几种；和/或
    所述方法中使用溶剂，且所述溶剂为选自异丙醇、乙醇、丙酮、四氢呋喃、环己烷和水中的一种或多种；和/或
    催化剂与作为反应底物的含氯的饱和或芳香有机化合物的质量比为0.05-0.8:1，优选0.1-0.3：1；和/或
    所述复合材料中，镍与钯的质量比为3:1～10:1，优选为3:1～6:1；和/或
    以所述复合材料为基准，镍和钯的总质量分数为20％～80％，优选为50％～80％。
  16. 根据权利要求11-14中任一项所述的方法，其进一步包括以下步骤：采用磁分离从反应产物中对权利要求1所述的复合材料、权利要求7所述的改性的碳包覆镍钯合金纳米粒子的复合材料进行分离的步骤。
  17. 权利要求1所述的复合材料或权利要求7所述的改性的碳包覆镍钯合金纳米粒子的复合材料作为加氢催化剂用于催化加氢的应用，优选的是氢气和/或加氢底物中含有含硫化合物。
PCT/CN2023/134959 2022-05-31 2023-11-29 碳包覆镍钯合金纳米粒子的复合材料及其制备方法和应用 Ceased WO2024239574A1 (zh)

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN120733765A (zh) * 2025-09-04 2025-10-03 江苏扬农化工集团有限公司 一种碳包覆非贵金属负载型改性加氢脱卤催化剂
CN121467091A (zh) * 2026-01-09 2026-02-06 广州航海学院 一种核壳结构的双金属催化剂及其制备方法和应用

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114426506A (zh) * 2020-10-12 2022-05-03 中国石油化工股份有限公司 催化加氢制备硫代芳胺的方法
CN114425341A (zh) * 2020-10-12 2022-05-03 中国石油化工股份有限公司 含硫化物杂质的不饱和化合物的催化加氢方法

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
TWI791574B (zh) * 2017-07-28 2023-02-11 中國大陸商中國石油化工科技開發有限公司 碳包覆過渡金屬奈米複合材料、其製備及應用
CN108579760A (zh) * 2018-04-10 2018-09-28 北京化工大学 一种碳包覆的镍铁合金纳米催化剂及其制备方法和用途
WO2020138647A1 (ko) * 2018-12-28 2020-07-02 부산대학교 산학협력단 촉매의 제조 방법 및 촉매

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114426506A (zh) * 2020-10-12 2022-05-03 中国石油化工股份有限公司 催化加氢制备硫代芳胺的方法
CN114425341A (zh) * 2020-10-12 2022-05-03 中国石油化工股份有限公司 含硫化物杂质的不饱和化合物的催化加氢方法

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
MARTíNEZ DE YUSO ALICIA; LE MEINS JEAN-MARC; OUMELLAL YASSINE; PAUL-BONCOUR VALéRIE; ZLOTEA CLAUDIA; MATEI GHIMBEU CAMEL: "Facile and rapid one-pot microwave-assisted synthesis of Pd-Ni magnetic nanoalloys confined in mesoporous carbons", JOURNAL OF NANOPARTICLE RESEARCH, SPRINGER NETHERLANDS, DORDRECHT, vol. 18, no. 12, 13 December 2016 (2016-12-13), Dordrecht, pages 1 - 14, XP036116994, ISSN: 1388-0764, DOI: 10.1007/s11051-016-3682-9 *
YUAN YING, ZHENG LUFAN, RONG JUNFENG, ZHAO XIKANG, WU GENGHUANG, ZHUANG ZHONGBIN: "Revealing the Crystal Phase‐Activity Relationship on NiRu Alloy Nanoparticles Encapsulated in N‐Doped Carbon towards Efficient Hydrogen Evolution Reaction", CHEMISTRY - A EUROPEAN JOURNAL, JOHN WILEY & SONS, INC, DE, vol. 29, no. 26, 8 May 2023 (2023-05-08), DE, XP093242554, ISSN: 0947-6539, DOI: 10.1002/chem.202300062 *

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN120733765A (zh) * 2025-09-04 2025-10-03 江苏扬农化工集团有限公司 一种碳包覆非贵金属负载型改性加氢脱卤催化剂
CN120733765B (zh) * 2025-09-04 2025-11-21 江苏扬农化工集团有限公司 一种碳包覆非贵金属负载型改性加氢脱卤催化剂
CN121467091A (zh) * 2026-01-09 2026-02-06 广州航海学院 一种核壳结构的双金属催化剂及其制备方法和应用

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