CN112755995A - Carbon-coated nickel-aluminum nanocomposite and preparation method and application thereof - Google Patents

Carbon-coated nickel-aluminum nanocomposite and preparation method and application thereof Download PDF

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CN112755995A
CN112755995A CN201911002468.3A CN201911002468A CN112755995A CN 112755995 A CN112755995 A CN 112755995A CN 201911002468 A CN201911002468 A CN 201911002468A CN 112755995 A CN112755995 A CN 112755995A
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nickel
aluminum
nanocomposite
salt
carbon
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于鹏
荣峻峰
林伟国
宗明生
谢婧新
吴耿煌
纪洪波
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Sinopec Research Institute of Petroleum Processing
China Petroleum and Chemical Corp
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China Petroleum and Chemical Corp
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    • 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
    • B01J23/74—Iron group metals
    • B01J23/755—Nickel
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
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    • B01D53/74—General processes for purification of waste gases; Apparatus or devices specially adapted therefor
    • B01D53/86—Catalytic processes
    • B01D53/8621—Removing nitrogen compounds
    • B01D53/8625—Nitrogen oxides
    • B01D53/8628—Processes characterised by a specific catalyst
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    • 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
    • B01J23/76—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper combined with metals, oxides or hydroxides provided for in groups B01J23/02 - B01J23/36
    • B01J23/78—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper combined with metals, oxides or hydroxides provided for in groups B01J23/02 - B01J23/36 with alkali- or alkaline earth metals
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    • B01D2255/00—Catalysts
    • B01D2255/20—Metals or compounds thereof
    • B01D2255/207—Transition metals
    • B01D2255/20753—Nickel
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2255/00—Catalysts
    • B01D2255/20—Metals or compounds thereof
    • B01D2255/209—Other metals
    • B01D2255/2092—Aluminium
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2255/00—Catalysts
    • B01D2255/70—Non-metallic catalysts, additives or dopants
    • B01D2255/702—Carbon
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2257/00—Components to be removed
    • B01D2257/40—Nitrogen compounds
    • B01D2257/402—Dinitrogen oxide
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    • Y02C—CAPTURE, STORAGE, SEQUESTRATION OR DISPOSAL OF GREENHOUSE GASES [GHG]
    • Y02C20/00—Capture or disposal of greenhouse gases
    • Y02C20/10—Capture or disposal of greenhouse gases of nitrous oxide (N2O)
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P20/00—Technologies relating to chemical industry
    • Y02P20/30—Improvements relating to adipic acid or caprolactam production

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Abstract

The invention provides a carbon-coated nickel-aluminum nanocomposite and a preparation method and application thereof, wherein the nanocomposite comprises a core-shell structure with a shell layer and a core, the shell layer is a graphitized carbon layer, and the core comprises simple substance nickel and aluminum oxide; based on the total weight of the nano composite material, the carbon content is 1-8%, the simple substance nickel content is 65-85%, and the alumina content is 15-34%. The nano composite material can be used as a catalyst to effectively catalyze and decompose nitrous oxide, and is beneficial to solving the problem of high-concentration N generated in the production processes of adipic acid plants, nitric acid plants and the like2The elimination of the O waste gas has important significance for protecting the environment and reducing the atmospheric pollution, and has good industrial application prospect.

Description

Carbon-coated nickel-aluminum nanocomposite and preparation method and application thereof
Technical Field
The invention relates to the technical field of catalysis and environmental protection, in particular to a carbon-coated nickel-aluminum nano composite material and a preparation method and application thereof.
Background
Magnetic metallic nickel nanoparticles are receiving much attention because of their excellent optical, electrical, and magnetic properties. However, the metal nickel nanoparticles have high activity, are easy to agglomerate or be oxidized or even burn in the air, and greatly influence the performance and application of the materials. Meanwhile, as a non-metallic material, the nano carbon material has the advantages of acid and alkali corrosion resistance, stable chemical property and the like. In recent years, nanocarbon-coated metal composite materials have become a focus of attention. The material takes single-layer to multiple-layer bent graphitized carbon layers as metal nano particles with shells tightly wrapping the inner core, and the nano particles are isolated from the outside, so that the stability of the composite material is greatly improved. Therefore, the unique core-shell structure nano material has wide application prospect in the fields of catalytic materials, wave absorbing materials, information storage materials, magneto-optical materials, biomedical materials, lubricating oil additives and the like.
Nitrous oxide (N)2O), also known as laughing gas, is an important greenhouse gas whose Global Warming Potential (GWP) is CO2310 times of, CH421 times of the total weight of the composition; furthermore, N2The average life of O in the atmosphere is about 150 years, and the O is also the main source of NOx in the stratosphere, not only can seriously damage the ozone layer, but alsoHas strong greenhouse effect.
The domestic production of adipic acid mainly adopts a cyclohexanol nitric acid oxidation method, and the cyclohexanol is subjected to nitric acid oxidation to produce adipic acid, and the method is mature in technology, high in product yield and purity, but large in nitric acid consumption, and capable of producing a large amount of N in the reaction process2And the tail gas discharged in the production process is concentrated, large in quantity and high in concentration (36-40%). At present, 15 ten thousand tons of adipic acid and N are produced annually by a nitric acid oxidation method of cyclohexanol2The annual emission of O can reach 4.5 ten thousand tons. Therefore, the tail gas of the adipic acid device is purified, and N is effectively controlled and eliminated2O has become a research hotspot in the field of environmental catalysis at present.
By direct catalytic decomposition of N2O is decomposed into nitrogen and oxygen to eliminate N2O is the most efficient and clean technique. Among them, the catalyst is the core of the direct catalytic decomposition method. Decomposition of N reported in the present study2The catalyst of O mainly comprises noble metal catalyst, ion-exchanged molecular sieve catalyst and transition metal oxide catalyst. Noble metal catalysts (e.g., Rh and Ru) vs. N2The O catalytic decomposition has higher low-temperature catalytic activity (within the range of 250-350 ℃) and can efficiently decompose N2O), but the expensive price limits the large-scale application of noble metal catalysts. The price of molecular sieve catalyst and transition metal oxide catalyst is obviously lower than that of noble metal, but at present, the two catalysts are used for N2The activity of O catalytic decomposition is low, the temperature range of efficient decomposition is 450-550 ℃, and the decomposition can be carried out only by diluting high-concentration laughing gas to about 0.5-2% concentration, thereby greatly improving the industrial cost.
Thus, a low cost, highly active catalyst is developed which is N2The field of O emission reduction is a problem to be solved urgently.
It is noted that the information disclosed in the foregoing background section is only for enhancement of background understanding of the invention and therefore it may contain information that does not constitute prior art that is already known to a person of ordinary skill in the art.
Disclosure of Invention
It is a primary object of the present invention to overcome the above-mentioned problemsAt least one defect of the prior art provides a carbon-coated nickel-aluminum nanocomposite material, a preparation method and an application, the nanocomposite material comprises a core-shell structure with a graphitized carbon layer shell and a nickel and aluminum oxide core, and the core-shell structure can be used as a catalyst to effectively catalyze and decompose nitrous oxide, thereby being beneficial to solving the problem of high concentration N generated in the production processes of adipic acid plants, nitric acid plants and the like2The elimination of O has important significance for protecting environment and reducing atmospheric pollution, and has good industrial application prospect.
In order to achieve the purpose, the invention adopts the following technical scheme:
one aspect of the invention provides a carbon-coated nickel-aluminum nanocomposite, which comprises a core-shell structure with a shell layer and a core, wherein the shell layer is a graphitized carbon layer, and the core comprises simple substance nickel and aluminum oxide; based on the total weight of the nano composite material, the carbon content is 1-8%, the simple substance nickel content is 65-85%, and the alumina content is 15-34%.
According to one embodiment of the invention, the nanocomposite material has a specific surface area of 100m2/g～300m2/g。
According to one embodiment of the invention, the pore volume of the nanocomposite is 0.3cm3/g～0.8cm3/g。
According to one embodiment of the invention, the core-shell structure has a particle size of 5nm to 80 nm.
According to one embodiment of the invention, the inner core further comprises an alkali metal oxide, the content of alkali metal oxide in mass percent in the nanocomposite material being not more than 5%, preferably not more than 2.5%.
The second aspect of the invention provides a preparation method of a carbon-coated nickel-aluminum nanocomposite, which comprises the following steps: preparing a nickel-aluminum precursor; heating the nickel-aluminum precursor; the product after the temperature rise heat treatment is contacted with hydrogen to carry out reduction treatment for 120-480 min; and (3) carrying out vapor deposition on the product after the reduction treatment by using low-carbon alkane as a carbon source gas to obtain the nano composite material.
According to one embodiment of the present invention, the manner of preparing the nickel aluminum precursor is coprecipitation and/or hydrothermal crystallization.
According to one embodiment of the present invention, the step of preparing the nickel aluminum precursor comprises: simultaneously dripping alkali liquor and aqueous solution containing trivalent aluminum salt and divalent nickel salt into water for precipitation treatment to enable trivalent aluminum salt and divalent nickel salt to generate coprecipitate; and aging the coprecipitate.
According to one embodiment of the invention, the trivalent aluminum salt comprises aluminum nitrate and/or aluminum chloride, the divalent nickel salt comprises nickel nitrate and/or nickel chloride, and the molar ratio of aluminum in the trivalent aluminum salt to nickel in the divalent nickel salt is 1: (2-4); the alkali liquor is an aqueous solution containing sodium hydroxide and sodium carbonate, the concentration of the sodium hydroxide in the alkali liquor is 0.2-4 mol/L, and the concentration of the sodium carbonate is 0.1-2 mol/L; the ratio of the mole number of the sodium hydroxide to the total mole number of the aluminum and the nickel in the trivalent aluminum salt and the divalent nickel salt is (2-4): 1, the ratio of the mole number of the sodium carbonate to the total mole number of the aluminum and the nickel in the trivalent aluminum salt and the divalent nickel salt is (0.5-2): 1.
according to one embodiment of the present invention, the precipitation treatment temperature is 40 ℃ to less than 100 ℃, the aging treatment temperature is 40 ℃ to less than 100 ℃, and the aging treatment time is 2 to 48 hours.
According to one embodiment of the invention, the method further comprises the steps of mixing a nickel-aluminum precursor with a salt solution of alkali metal for coprecipitation reaction, and then heating the obtained precipitate, wherein the molar ratio of the alkali metal to the nickel is not more than 0.2.
According to one embodiment of the invention, the heating treatment comprises heating the nickel-aluminum precursor to 500-900 ℃ under the condition of introducing protective gas, wherein the protective gas is nitrogen and/or argon, the flow rate of the protective gas is 10-500 ml/(min. g nickel-aluminum precursor), and the heating speed is 1-5 ℃/min; the temperature of vapor deposition is 750-900 ℃, preferably 780-850 ℃, and the time is 5-240 min, preferably 60-120 min; the carbon source gas is preferably methane or ethane, and the flow rate of the carbon source gas is 10-500 ml/(min g nickel-aluminum precursor), preferably 30-100 ml/(min g nickel-aluminum precursor), and more preferably 30-60 ml/(min g nickel-aluminum precursor).
A third aspect of the present invention provides the use of a nanocomposite as described above as a catalyst for the decomposition of nitrous oxide, comprising: the catalyst is contacted with nitrous oxide to carry out catalytic decomposition reaction to generate nitrogen and oxygen.
According to one embodiment of the present invention, the temperature of the catalytic decomposition reaction is 300 ℃ to 400 ℃.
According to one embodiment of the invention, the space velocity of the catalytic decomposition reaction is 1000h-1～3000h-1。
According to one embodiment of the invention, the nitrous oxide has a volume concentration comprised between 30% and 40%.
According to the technical scheme, the carbon-coated nickel-aluminum nano composite material and the preparation method and application thereof have the advantages and positive effects that:
the carbon-coated nickel-aluminum nano composite material provided by the invention comprises a core-shell structure with a graphitized carbon layer shell and a nickel and aluminum oxide core, and can be used for catalyzing N when being used as a catalyst2Has excellent activity in O decomposition reaction, and compared with the prior catalyst, the catalyst has the advantage that N in industrial waste gas must be added2The catalyst can be used for catalytically decomposing high-concentration nitrous oxide waste gas generated in industrial production at a lower temperature, the decomposition rate can reach more than 99 percent, and the catalyst has important significance for protecting the environment and reducing the atmospheric pollution and has good industrial application prospect.
Drawings
The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention and not to limit the invention.
FIG. 1 is an X-ray diffraction pattern of the nanocomposite of example 1;
FIG. 2 is a transmission electron microscope photograph of the nanocomposite material of example 1;
FIG. 3 is an X-ray diffraction pattern of the nanocomposite of example 2;
FIG. 4 is a transmission electron microscope photograph of the nanocomposite material of example 2.
Detailed Description
The following presents various embodiments or examples in order to enable those skilled in the art to practice the invention with reference to the description herein. These are, of course, merely examples and are not intended to limit the invention. The endpoints of the ranges and any values disclosed in the present application are not limited to the precise range or value, and such ranges or values should be understood to encompass values close to those ranges or values. For ranges of values, between the endpoints of each of the ranges and the individual points, and between the individual points may be combined with each other to yield one or more new ranges of values, which ranges of values should be considered as specifically disclosed herein.
Any terms not directly defined herein should be understood to have meanings associated with them as commonly understood in the art of the present invention. The following terms as used throughout this specification should be understood to have the following meanings unless otherwise indicated.
The core-shell structure in the invention means that the inner core comprises simple substance nickel and alumina, and the shell layer is a graphitized carbon layer structure. The term "graphitized carbon layer" means a carbon structure in which a layered structure is clearly observed under a high-resolution transmission electron microscope, not an amorphous structure, and the interlayer distance is about 0.34 nm.
One aspect of the invention provides a carbon-coated nickel-aluminum nanocomposite, which comprises a core-shell structure with a shell layer and a core, wherein the shell layer is a graphitized carbon layer, and the core comprises simple substance nickel and aluminum oxide; based on the total weight of the nano composite material, the carbon content is 1-8%, the simple substance nickel content is 65-85%, and the alumina content is 15-34%.
According to the invention, the nickel-aluminum material is a good catalytic material, and has the advantages of high activity, simple preparation and the like, but the surface active sites of the nickel-aluminum material are easy to sinter at high temperature so as to inactivate the nickel-aluminum material. The inventor of the present invention finds that the carbon-coated nickel-aluminum composite material prepared by coating (coating) the graphite shell on the outer surface of the nickel-aluminum material has the advantages of high activity, low reaction temperature, etc., which may be because the surface active sites of the nickel-aluminum material used at high temperature are easily lost due to sintering of the material, and the surface active sites are separated by the graphite shell after the graphite shell is used for coating the nickel-aluminum material, thereby effectively reducing the inactivation of the nickel-aluminum material, improving the activity of the composite material and reducing the reaction temperature. In addition, the graphitized carbon layer has abundant defect sites on the surface, and the carbon material has catalytic activity and can play a role in cooperation with nickel nanoparticles, so that the nano composite material has better catalytic performance. Because the catalyst material contains the graphitized carbon layer/metal core-shell structure, no pore channel or defect which can enable reactants to approach the center of nickel exists, so that the nickel material of the core is very stable, does not self-ignite, is resistant to acid corrosion and low in danger, and is suitable for storage and transportation, thereby ensuring the use safety of the composite material. The catalyst material of the invention is very stable, does not self-ignite, resists oxidation, resists acid corrosion, has low danger, and is suitable for storage and transportation, thereby ensuring the safety of the synthesis process. The nano composite material also has stronger magnetism, and can conveniently utilize the magnetism thereof to separate catalysts or be used for processes such as a magnetic stabilization bed and the like.
In some embodiments, the nanocomposite has a specific surface area of 100m2/g～300m2/g。
In some embodiments, the pore volume of the nanocomposite is 0.3cm3/g～0.8cm3/g。
In some embodiments, the core-shell structure has a particle size of 5nm to 80 nm. According to the invention, the particle size of the composite material has a great influence on the catalytic effect, the larger the particle size of the composite material is, the fewer the surface active sites are, and the smaller the particle size of the composite material is, the easier the particles are sintered at a lower temperature, so that through experiments, the particle size of the composite material is preferably 5 nm-80 nm, and more preferably 10-30 nm.
In some embodiments, the core of the nanocomposite of the present invention may further include an alkali metal oxide to enhance the performance of the material, depending on the requirements of the actual application. Wherein, the content of the alkali metal oxide accounts for no more than 5 percent of the content of the nano composite material by mass percent, and preferably no more than 2.5 percent.
The second aspect of the invention provides a preparation method of a carbon-coated nickel-aluminum nanocomposite, which comprises the following steps: preparing a nickel-aluminum precursor; heating the nickel-aluminum precursor; the product after the temperature rise heat treatment is contacted with hydrogen to carry out reduction treatment for 120-480 min; and (3) carrying out vapor deposition on the product after the reduction treatment by using low-carbon alkane as a carbon source gas to obtain the nano composite material.
According to the preparation method provided by the invention, a nickel-aluminum precursor is prepared, and then the graphite shell is wrapped on the outer surface of the nickel-aluminum core in a vapor deposition mode. The nickel-aluminum precursor prepared by the invention generally has a hydrotalcite crystal structure, and can be prepared by various ways by those skilled in the art, such as coprecipitation and/or hydrothermal crystallization.
Specifically, the nickel aluminum precursor may be prepared by, but is not limited to, the following method.
According to a specific embodiment of the present invention, the nickel aluminum precursor is prepared by a coprecipitation method, and the specific steps may include: simultaneously dripping alkali liquor and aqueous solution containing trivalent aluminum salt and divalent nickel salt into water for precipitation treatment to enable trivalent aluminum salt and divalent nickel salt to generate coprecipitate; the coprecipitate is aged. The feeding amount of the aqueous solution containing the trivalent aluminum salt and the divalent nickel salt can be controlled according to the nickel-aluminum content in the target carbon-coated nickel-aluminum composite material, and the adding amount of the alkali liquor is controlled according to the condition that the trivalent aluminum salt and the divalent nickel salt are completely precipitated. The simultaneous addition of the alkali solution, the trivalent aluminum salt and the divalent nickel salt to the water can improve the dispersion effect of the alkali solution, the aluminum salt and the nickel salt during the initial dropwise addition. In addition, the trivalent aluminum salt and the divalent nickel salt are not particularly limited as long as they are soluble in water, and the alkali in the alkali solution is not particularly limited as long as they are capable of precipitating the trivalent aluminum salt and the divalent nickel salt, for example, the trivalent aluminum salt may include aluminum nitrate and/or aluminum chloride, the divalent nickel salt may include nickel nitrate and/or nickel chloride, and the molar ratio of aluminum in the trivalent aluminum salt to nickel in the divalent nickel salt may be 1: (2-4), the molar concentration of the trivalent aluminum salt can be 0.3-0.6 mol/L; the alkali liquor can be an aqueous solution containing sodium hydroxide and sodium carbonate, the concentration of the sodium hydroxide in the alkali liquor can be 0.2-4 mol/L, and the concentration of the sodium carbonate can be 0.1-2 mol/L; the ratio of the number of moles of sodium hydroxide to the total number of moles of aluminum and nickel in the trivalent aluminum salt and the divalent nickel salt may be (2-4): the ratio of the number of moles of the sodium carbonate to the total number of moles of aluminum and nickel in the trivalent aluminum salt and the divalent nickel salt can be (0.5-2): 1.
according to the invention, the precipitation treatment refers to a process of generating a precipitate from trivalent aluminum salt and divalent nickel salt by using an alkali solution, wherein the alkali solution can be mixed with the trivalent aluminum salt and the divalent nickel salt in various ways such as dripping, pumping or pouring. The aging treatment refers to further reacting the precipitate generated by the precipitation treatment to obtain the nickel-aluminum hydrotalcite crystal. The steps of the precipitation treatment and the aging treatment are not particularly limited, and only a nickel-aluminum precursor is obtained, for example, the conditions of the precipitation treatment may include: the temperature may be room temperature to less than 100 deg.c, preferably 40 deg.c to less than 100 deg.c, to increase the speed of the precipitation process. After the dropwise addition is started, the nickel ions and the aluminum ions are controlled to be precipitated under the condition that the pH value is greater than 7, preferably between 8 and 9, and the specific operation can be as follows: controlling the pH value of the aqueous solution to be between 8 and 9 through the dropping speed of the alkali liquor, accelerating the dropping speed of the alkali liquor if the pH value is lower than 8, and slowing down the dropping speed of the alkali liquor if the pH value is higher than 9; the aging treatment conditions may include: the temperature is 40 ℃ to less than 100 ℃, and the time is 2-72 hours, preferably 6-72 hours, and more preferably 24-48 hours. The nickel-aluminum hydrotalcite crystal obtained by aging treatment can be further washed to be neutral and dried to obtain a nickel-aluminum precursor.
In some embodiments, the temperature-rising heat treatment includes rising the temperature of the nickel-aluminum precursor to 500-900 ℃ in the presence of a protective gas, wherein the protective gas is nitrogen and/or argon, the flow rate of the protective gas is 30-500 ml/(min-g nickel-aluminum precursor), and the temperature-rising speed is 1-5 ℃/min. The protective gas is used as a carrier gas in the temperature rise process of the nickel-aluminum precursor, so that the danger of contact with air is avoided when the reduction and carbon deposition reaction of the nickel-aluminum precursor is carried out, and the graphite shell is prevented from being oxidized when contacting with air at high temperature after being coated with the graphite shell.
After the temperature rise heat treatment, the product is contacted with hydrogen for reduction treatment. The reduction treatment has the functions of: on the one hand, the nickel-aluminum precursor existing in the form of hydroxide (hydrotalcite) is further dehydrated, and on the other hand, the generated nickel-aluminum oxide is reduced to generate simple substance nickel as an active center. The conditions of the hydrogen reduction treatment may include: the temperature is 500-900 ℃, the time is 120-480 minutes, and the hydrogen flow is 30-50 ml/(min. g nickel-aluminum precursor).
After the reduction treatment, a graphite carbon shell is formed on the surface of the material through vapor deposition. The temperature of the vapor deposition is 750-900 ℃, preferably 780-850 ℃, and the time is 5-240 min, preferably 60-120 min; the carbon source gas is preferably methane or ethane, and the flow rate of the carbon source gas is 10-500 ml/(min g nickel-aluminum precursor), preferably 30-100 ml/(min g nickel-aluminum precursor), and more preferably 30-60 ml/(min g nickel-aluminum precursor).
In some embodiments, the present invention further comprises mixing a nickel aluminum precursor with a salt solution of an alkali metal to perform a coprecipitation reaction, and subjecting the obtained precipitate to the aforementioned temperature-increasing heat treatment, wherein the molar ratio of the alkali metal to the nickel is not greater than 0.2. The inventors of the present invention have found that N is catalyzed when this material is used as a catalyst by the aforementioned coprecipitation reaction with a small amount of alkali metal before the temperature-raising heat treatment2When an acidic oxide such as O reacts, the catalytic activity is further improved.
According to the method, the nano composite material with the shell of the graphitized carbon layer and the core of the core-shell structure of the simple substance nickel and the alumina is obtained. The material has a plurality of excellent performances through the unique structure and composition, so that the material has great application potential in the aspects of catalytic materials, energy storage materials, electromagnetic materials and the like.
A third aspect of the present invention provides the use of a nanocomposite as described above as a catalyst for the decomposition of nitrous oxide, comprising: the catalyst is contacted with nitrous oxide to carry out catalytic decomposition reaction to generate nitrogen and oxygen. Specifically, a gas containing dinitrogen monoxide is introduced into a reactor containing the catalyst to perform a catalytic decomposition reaction.
In some embodiments, the temperature of the catalytic decomposition reaction is from 300 ℃ to 400 ℃, preferably from 350 ℃ to 380 ℃. The space velocity of the catalytic decomposition reaction is 1000h-1～3000h-1. The space velocity of the reaction is the amount of gas treated per unit volume of catalyst per unit time under the specified conditions, and is expressed in m3/(m3Catalyst h) can be simplified to h-1. The high reaction space velocity allowed by the invention shows that the catalyst has high activity and large device processing capacity when the reaction is applied.
According to the invention, as mentioned above, the currently reported decomposition N2The catalyst of O mainly comprises noble metal catalyst, ion-exchanged molecular sieve catalyst and transition metal oxide catalyst. Although the decomposition temperature of the noble metal catalyst is low, the expensive price of the noble metal catalyst is not suitable for large-scale industrial production; the high-efficiency decomposition temperature of other molecular sieve catalysts and transition metal oxide catalysts is 450-550 ℃, and the high temperature required by the reaction greatly improves the industrial cost; in addition, the decomposition of nitrous oxide generates oxygen, which tends to deactivate the catalyst.
The inventors of the present invention have found that the carbon-coated nickel-aluminum nanocomposite of the present invention can effectively decompose nitrous oxide into nitrogen and oxygen using as a catalyst, and exhibits excellent catalytic activity stability in the reaction. In addition, when the existing catalyst is used for catalyzing and decomposing the nitrous oxide, the high-concentration nitrous oxide obtained by industrial production generally needs to be diluted to be about 0.5-2 percent, and the catalyst can be directly decomposed to achieve a high decomposition rate without being diluted. Namely, the nitrous oxide can be subjected to catalytic decomposition reaction with the volume concentration of 30-40%, and the decomposition rate can reach more than 99%, so that the industrial cost is greatly reduced, and the method has a good industrial application prospect.
The invention will be further illustrated by the following examples, but is not to be construed as being limited thereto. Unless otherwise specified, all reagents used in the invention are analytically pure.
The analysis of carbon (C) element is carried out on an Elementar Micro Cube element analyzer which is mainly used for analyzing four elements of carbon (C), hydrogen (H), oxygen (O) and nitrogen (N), and the specific operation method and conditions are as follows: weighing 1-2 mg of a sample in a tin cup, placing the sample in an automatic sample feeding disc, feeding the sample into a combustion tube through a ball valve for combustion, wherein the combustion temperature is 1000 ℃ (the atmosphere interference during sample feeding is removed, helium is adopted for blowing), and then reducing the combusted gas by using reduced copper to form nitrogen, carbon dioxide and water. The mixed gas is separated by three desorption columns and sequentially enters a TCD detector for detection. The oxygen element is analyzed by converting oxygen in a sample into CO under the action of a carbon catalyst by utilizing pyrolysis, and then detecting the CO by adopting TCD. Since the composite material of the present invention contains only carbon and a metal oxide, the total content of the metal oxide can be determined from the content of the carbon element.
The ratio between the different metal oxides was measured by an X-ray fluorescence spectrometer (XRF), and the content of the different metal oxides in the composite material was calculated from the known content of carbon element. The X-ray fluorescence spectrum analyzer (XRF) adopted by the invention is a Rigaku 3013X-ray fluorescence spectrometer, and the X-ray fluorescence spectrum analysis and test conditions are as follows: the scanning time was 100s and the atmosphere was air.
The high-resolution transmission electron microscope (HRTEM) adopted by the invention is JEM-2100(HRTEM) (Nippon electronics Co., Ltd.), and the test conditions of the high-resolution transmission electron microscope are as follows: the acceleration voltage was 200 kV.
The model of the XRD diffractometer adopted by the invention is an XRD-6000X-ray powder diffractometer (Shimadzu Japan), and the XRD test conditions are as follows: the Cu target was irradiated with K α rays (wavelength λ is 0.154nm), tube voltage was 40kV, tube current was 200mA, and scanning speed was 10 ° (2 θ)/min.
Example 1
This example illustrates the preparation of a carbon-coated nickel aluminum nanocomposite material according to the invention.
(1) Weighing 11.64g (0.04mol) of nickel nitrate hexahydrate and 7.5g (0.02mol) of aluminum nitrate nonahydrate, adding 60ml of deionized water to prepare a mixed salt solution, preparing a mixed alkali solution by adding 5.40g (0.135mol) of sodium hydroxide, 5.08g (0.048mol) of anhydrous sodium carbonate and 120ml of deionized water, simultaneously dripping the two mixed solutions into a 100ml of deionized water three-neck flask which is pre-filled with constant temperature of 60 ℃, stirring simultaneously, strictly controlling the pH value of the precipitate of the trivalent aluminum salt and the divalent nickel salt in the three-neck flask to be 8.4 (namely controlling the pH value to be 8.3-8.5), continuously stirring at 60 ℃ for 30min after finishing dripping, aging at 80 ℃ for 24h, centrifuging and washing to be neutral, drying at 80 deg.C for 4 hr, mixing with 0.14g (0.001mol) potassium carbonate, adding 150ml deionized water, stirring at 60 deg.C for 10 hr, and drying at 80 deg.C for 10 hr to obtain nickel-aluminum precursor coprecipitated with alkali metal.
(2) Weighing 1.0g of the nickel-aluminum precursor obtained in the step (1), placing the nickel-aluminum precursor into a porcelain boat, then placing the porcelain boat into a tubular furnace in a nitrogen protective atmosphere, carrying out programmed temperature rise of 5 ℃/min at the nitrogen flow of 100mL/min, raising the temperature to 500 ℃, introducing 30mL/min of hydrogen for 180min, and closing the hydrogen; and continuously raising the temperature to 800 ℃, introducing 50mL/min of methane at the temperature, reacting for 60min, closing the methane after the reaction is finished, and naturally cooling in a nitrogen atmosphere to obtain the nano composite material.
Material characterization:
FIG. 1 is an X-ray diffraction pattern (XRD) of the nanocomposite material of example 1. from FIG. 1, it can be seen that the material has only the characteristic peaks of reduced nickel, but not the characteristic peaks of alumina and potassium oxide, indicating that alumina and potassium oxide exist in an amorphous form. X-ray fluorescence spectroscopy (XRF) and elemental analysis showed that the nanocomposite had a carbon content of 6.70 wt%, an elemental nickel content of 67.51 wt%, a potassium oxide content of 1.73 wt%, and an aluminum oxide content of 23.97 wt%. Fig. 2 is a Transmission Electron Microscope (TEM) image of the nanocomposite material of example 1, which shows that the material surface has a graphitized carbon layer and is coated with a nickel-aluminum core to form a complete core-shell structure, and the particle size is about 10nm to 20 nm. TheThe nanocomposite material has a specific surface area of 134m2Per g, pore volume 0.51cm3/g。
Example 2
This example illustrates the preparation of a carbon-coated nickel aluminum nanocomposite material according to the invention.
(1) Weighing 11.64g (0.04mol) of nickel nitrate hexahydrate and 7.5g (0.02mol) of aluminum nitrate nonahydrate, adding 60ml of deionized water to prepare a mixed salt solution, adding 5.40g (0.135mol) of sodium hydroxide and 5.08g (0.048mol) of anhydrous sodium carbonate and 120ml of deionized water to prepare a mixed alkali solution, simultaneously dropwise adding the two mixed solutions into a 100ml of deionized water pre-filled with constant temperature of 60 ℃, stirring simultaneously, strictly controlling the pH value of the precipitate of trivalent aluminum salt and divalent nickel salt in the three-neck flask to be 8 (namely controlling the precipitate to be 7.9-8.1), continuously stirring at 60 ℃ for 30min after dropwise adding, aging at 80 ℃ for 24h, centrifugally washing to be neutral, and drying at 80 ℃ to obtain the nickel-aluminum precursor.
(2) Weighing 1.0g of the nickel-aluminum precursor obtained in the step (1), placing the nickel-aluminum precursor into a porcelain boat, then placing the porcelain boat into a tubular furnace in a nitrogen protective atmosphere, carrying out programmed temperature rise of 5 ℃/min at the nitrogen flow of 100mL/min, raising the temperature to 500 ℃, introducing 30mL/min of hydrogen for 120min, and closing the hydrogen; and continuously raising the temperature to 800 ℃, introducing 50mL/min of methane at the temperature, reacting for 60min, closing the methane after the reaction is finished, and naturally cooling in a nitrogen atmosphere to obtain the nano composite material.
Material characterization:
FIG. 3 is an X-ray diffraction (XRD) spectrum of the nanocomposite material of example 2. from FIG. 3, it can be seen that the material has only the characteristic peak of reduced nickel and no characteristic peak of alumina, indicating that alumina exists in an amorphous form. As can be seen from X-ray fluorescence spectrum analysis (XRF) and elemental analysis, the nanocomposite had a carbon content of 7.28 wt%, an elemental nickel content of 68.41 wt%, and an alumina content of 24.31 wt%. Fig. 4 is a Transmission Electron Microscope (TEM) image of the nanocomposite material of example 2, which shows that the material surface has a graphitized carbon layer and is coated with a nickel-aluminum core to form a complete core-shell structure, and the particle size is about 10nm to 20 nm. The nano-compositeThe specific surface area of the material is 151m2Per g, pore volume 0.59cm3/g。
Comparative example 1
Placing the nickel-aluminum precursor obtained in the step (1) in the embodiment 1 into a porcelain boat, then placing the porcelain boat into a tubular furnace in a nitrogen protection atmosphere, carrying out temperature programming at 5 ℃/min under the nitrogen flow of 100mL/min, heating to 500 ℃, introducing 30mL/min hydrogen for 120min, closing the hydrogen, and naturally cooling in the hydrogen atmosphere to obtain the nickel-aluminum composite material without carbon film coating.
Comparative example 1
Placing the nickel-aluminum precursor obtained in the step (1) in the embodiment 2 into a porcelain boat, then placing the porcelain boat into a tubular furnace in a nitrogen protection atmosphere, carrying out temperature programming at 5 ℃/min under the nitrogen flow of 100mL/min, heating to 500 ℃, introducing 30mL/min hydrogen for 120min, closing the hydrogen, and naturally cooling under the hydrogen atmosphere to obtain the nickel-aluminum composite material without carbon film coating.
Application example 1
This application example serves to illustrate the reaction of catalyzing the decomposition of nitrous oxide using the nanocomposite of example 1 as a catalyst.
0.5g of catalyst was placed in a continuous flow fixed bed reactor with the reaction gas consisting of 38.0% by volume N2O, using nitrogen as balance gas, the flow rate of the reaction gas is 15ml/min, and the space velocity is 1800h-1The activity evaluation temperature range is 300-500 ℃, and the catalyst is used for catalyzing and decomposing N at different temperatures2The conversion of O is shown in Table 1.
Application example 2
N Using the method of application example 12O decomposition reaction, except that the nanocomposite of example 2 was used as a catalyst, the results are shown in table 1.
Comparative application example 1
N Using the method of application example 12O decomposition reaction, except that the material of comparative example 1 was used as a catalyst, the results are shown in table 1.
Comparative application example 2
N Using the method of application example 12O decomposition reaction except thatThe material of comparative example 2 was used as a catalyst and the results are shown in table 1.
TABLE 1
Figure BDA0002241752950000121
As can be seen from Table 1 above, the carbon-coated nickel-aluminum nanocomposite prepared by the method of the present invention is superior to uncoated pure nickel-aluminum nanocomposite in the case of N2O has better catalytic decomposition performance, and N can be decomposed with high efficiency in a relatively low temperature range2O, whereas the materials of comparative examples 1 and 2 require a temperature of at least 465 ℃ for N to be present2The conversion rate of O reaches more than 99 percent, and the decomposition can be relatively complete. In addition, the composite material contains a certain content of alkali metal oxide, so that the catalytic performance is improved to a certain extent.
It can be seen that the nanocomposite material of the invention has good catalytic effect on the decomposition of nitrous oxide, and can efficiently decompose and eliminate N at a lower temperature2O, application thereof to industrial process waste gas N2In the treatment of O, e.g. high concentrations of N produced during the production in adipic acid plants and nitric acid plants2The elimination of O waste gas can greatly reduce the reaction temperature and the energy consumption, and has good industrial application prospect.
It should be noted by those skilled in the art that the described embodiments of the present invention are merely exemplary and that various other substitutions, alterations, and modifications may be made within the scope of the present invention. Accordingly, the present invention is not limited to the above-described embodiments, but is only limited by the claims.

Claims (16)

1. The carbon-coated nickel-aluminum nanocomposite is characterized by comprising a core-shell structure with a shell layer and a core, wherein the shell layer is a graphitized carbon layer, and the core comprises simple substance nickel and aluminum oxide; based on the total weight of the nano composite material, the carbon content is 1-8%, the elemental nickel content is 65-85%, and the alumina content is 15-34%.
2. Nanocomposite as claimed in claim 1, characterized in that the nanocomposite has a specific surface area of 100m2/g～300m2/g。
3. Nanocomposite as claimed in claim 1, characterized in that the pore volume of the nanocomposite is 0.3cm3/g～0.8cm3/g。
4. The nanocomposite of claim 1, wherein the core-shell structure has a particle size of 5nm to 80 nm.
5. Nanocomposite material according to claim 1, wherein the core further comprises an alkali metal oxide, the alkali metal oxide being present in an amount of not more than 5%, preferably not more than 2.5% by mass of the nanocomposite material.
6. A method for preparing the carbon-coated nickel-aluminum nanocomposite material according to any one of claims 1 to 5, comprising the steps of:
preparing a nickel-aluminum precursor;
heating the nickel-aluminum precursor;
the product after the temperature-rising heat treatment is contacted with hydrogen to carry out reduction treatment for 120-480 min;
and carrying out vapor deposition on the product after the reduction treatment by using low-carbon alkane as a carbon source gas to obtain the nano composite material.
7. The preparation method according to claim 6, wherein the manner of preparing the nickel aluminum precursor is coprecipitation and/or hydrothermal crystallization.
8. The method according to claim 6, wherein the step of preparing a nickel-aluminum precursor comprises:
simultaneously dripping alkali liquor and aqueous solution containing trivalent aluminum salt and divalent nickel salt into water for precipitation treatment to enable trivalent aluminum salt and divalent nickel salt to generate coprecipitate;
and aging the coprecipitate.
9. The method according to claim 8, wherein the trivalent aluminum salt comprises aluminum nitrate and/or aluminum chloride, the divalent nickel salt comprises nickel nitrate and/or nickel chloride, and the molar ratio of aluminum in the trivalent aluminum salt to nickel in the divalent nickel salt is 1: (2-4); the alkali liquor is an aqueous solution containing sodium hydroxide and sodium carbonate, the concentration of the sodium hydroxide in the alkali liquor is 0.2-4 mol/L, and the concentration of the sodium carbonate is 0.1-2 mol/L; the ratio of the mole number of the sodium hydroxide to the total mole number of the aluminum and the nickel in the trivalent aluminum salt and the divalent nickel salt is (2-4): 1, the ratio of the mole number of the sodium carbonate to the total mole number of the aluminum and the nickel in the trivalent aluminum salt and the divalent nickel salt is (0.5-2): 1.
10. the method according to claim 8, wherein the precipitation treatment is carried out at a temperature of 40 ℃ to less than 100 ℃, the aging treatment is carried out at a temperature of 40 ℃ to less than 100 ℃, and the aging treatment is carried out for 2 to 48 hours.
11. The preparation method according to claim 6, further comprising mixing the nickel aluminum precursor with a salt solution of an alkali metal to perform a coprecipitation reaction, and then subjecting the obtained precipitate to the temperature-increasing heat treatment, wherein the molar ratio of the alkali metal to nickel is not more than 0.2.
12. The preparation method according to claim 6, wherein the temperature-raising heat treatment comprises raising the temperature of the nickel-aluminum precursor to 500-900 ℃ in the presence of a protective gas, wherein the protective gas is nitrogen and/or argon, the flow rate of the protective gas is 10-500 ml/(min-g nickel-aluminum precursor), and the temperature-raising speed is 1-5 ℃/min; the vapor deposition temperature is 750-900 ℃, and the time is 5-240 minutes; the carbon source gas is methane or ethane, and the flow rate of the carbon source gas is 10-500 ml/(min. g nickel-aluminum precursor).
13. Use of a nanocomposite according to any one of claims 1 to 5 as a catalyst for decomposing nitrous oxide, comprising: and contacting the catalyst with nitrous oxide to perform a catalytic decomposition reaction to generate nitrogen and oxygen.
14. Use according to claim 13, wherein the temperature of the catalytic decomposition reaction is between 300 ℃ and 400 ℃.
15. Use according to claim 13, wherein the catalytic decomposition reaction has a space velocity of 1000h-1～3000h-1。
16. Use according to claim 13, wherein the nitrous oxide is present in a concentration of between 30% and 40% by volume.
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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103212417A (en) * 2013-04-19 2013-07-24 陕西科技大学 Preparation method of nickel oxide/alumina and nickel/alumina nanometer compound microparticle
CN105381801A (en) * 2015-11-12 2016-03-09 开滦（集团）有限责任公司 Catalyst capable of directly catalytically decomposing N2O
CN107469824A (en) * 2017-09-26 2017-12-15 天津工业大学 A kind of preparation method of the ethanol oxidation catalyst of the hollow crystal nickel oxide of carbon coating
CN108856706A (en) * 2017-05-10 2018-11-23 中国石油化工股份有限公司 A kind of carbon-coating nickel aluminium composite material and its preparation method and application

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103212417A (en) * 2013-04-19 2013-07-24 陕西科技大学 Preparation method of nickel oxide/alumina and nickel/alumina nanometer compound microparticle
CN105381801A (en) * 2015-11-12 2016-03-09 开滦（集团）有限责任公司 Catalyst capable of directly catalytically decomposing N2O
CN108856706A (en) * 2017-05-10 2018-11-23 中国石油化工股份有限公司 A kind of carbon-coating nickel aluminium composite material and its preparation method and application
CN107469824A (en) * 2017-09-26 2017-12-15 天津工业大学 A kind of preparation method of the ethanol oxidation catalyst of the hollow crystal nickel oxide of carbon coating

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
WU HAI-PENG ET AL: "Effect of promoter species and precursors on catalytic activity of alkali metal promoted NiAl mixed oxides for N2O decomposition", 《JOURNAL OF FUEL CHEMISTRY AND TECHNOLOGY》 *

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