CN115121252B - Carbon-coated nickel nanocomposite, and preparation method and application thereof - Google Patents

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

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CN115121252B
CN115121252B CN202110312060.7A CN202110312060A CN115121252B CN 115121252 B CN115121252 B CN 115121252B CN 202110312060 A CN202110312060 A CN 202110312060A CN 115121252 B CN115121252 B CN 115121252B
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nickel
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gas
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CN115121252A (en
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荣峻峰
于鹏
袁蕙
吴耿煌
谢婧新
宗明生
林伟国
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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    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01JCHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
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    • B01J23/70Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper
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    • B01J35/23Catalysts, in general, characterised by their form or physical properties characterised by their non-solid state in a colloidal state
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01JCHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J35/00Catalysts, in general, characterised by their form or physical properties
    • B01J35/30Catalysts, in general, characterised by their form or physical properties characterised by their physical properties
    • B01J35/396Distribution of the active metal ingredient
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    • B01J37/00Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
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    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
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    • B01J37/00Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
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    • B01J37/18Reducing with gases containing free hydrogen
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23COMBUSTION APPARATUS; COMBUSTION PROCESSES
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    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23COMBUSTION APPARATUS; COMBUSTION PROCESSES
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Abstract

The invention provides a carbon-coated nickel nanocomposite, a preparation method and application thereof, wherein the nanocomposite is provided with an outer membrane and an inner core nuclear membrane structure, the outer membrane is a graphitized carbon membrane, the inner core is nickel nano particles, and the main component of the nanocomposite is nickel, wherein the carbon content is only below 5wt%. The carbon-coated nickel nanocomposite provided by the invention can be used for catalyzing various chemical reactions, and has a wide application prospect.

Description

Carbon-coated nickel nanocomposite, and preparation method and application thereof
Technical Field
The invention relates to the technical field of catalysis, in particular to a carbon-coated nickel nanocomposite, a preparation method and application thereof.
Background
Magnetic metallic nickel nanoparticles are receiving a great deal of attention due to their excellent optical, electrical, and magnetic properties. However, the metallic nickel nano particles have high activity, are easy to agglomerate or oxidize and even burn in the air, and greatly influence the performance and application of the materials. Meanwhile, as a nonmetallic 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 composites have become a focus of attention. The material takes a single-layer to a plurality of curved graphitized carbon layers as a shell to tightly wrap the metal nano particles of the inner core, so that the nano particles are isolated from the outside, and 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.
Currently, methods for coating metal nanoparticles with carbon mainly include an arc method, a Chemical Vapor Deposition (CVD) method, a pyrolysis method, and the like. The arc method has the advantages of complex equipment, poor operability and high energy consumption, and is unfavorable for large-scale preparation of materials. Compared with the arc method, the CVD method has lower cost and higher yield and productivity, but has the difficulty that nano metal or compound particles with uniform size and good dispersion are required to be prepared firstly, and the particles of carbon nano tubes and amorphous carbon are often generated in the later products. Similar to CVD methods, the structure and properties of the products of pyrolysis methods are greatly affected by the precursor materials. But the pyrolysis method has the advantages of simple process, low cost, high yield, controllable metal content and the like, and is one of the methods with large-scale preparation prospect at present.
The pyrolysis method can be mainly divided into two main types, and the first method is to directly mix a carbon source (typically dicyandiamide, melamine, etc.) containing a heteroatom such as N and a metal source and then subject the mixture to high-temperature pyrolysis in an inert or reducing atmosphere. The dicyandiamide, melamine and other carbon sources are easy to decompose at high temperature, and the direct mixing interaction of the dicyandiamide, melamine and other carbon sources and metal particles is weak, so that the ligand utilization rate is low, and the carbonization yield is low. Furthermore, cyanamideThe carbon and nitrogen sources are used as the substances which are easy to promote the generation of the carbon nano tube. Another class of methods involves first forming metal-organic framework compounds (MOFs) as precursors by self-assembling and linking metal ions with nitrogen-containing organic ligands under a characteristic reaction. Unlike the pyrolysis of cyanamides, the metal in MOF forms an atomic level uniform dispersion and is therefore considered as a more ideal pyrolysis precursor, which has become a research hot spot in recent years in this field. For example, chinese patent CN 1055965009A discloses a method for preparing a precursor by coordinating with ni2+ under high temperature and high pressure conditions by using aspartic acid, 4' -bipyridine as ligands and methanol and water as solvents, and performing pyrolysis under inert atmosphere to prepare carbon-coated nickel nanoparticles. An (DOI: 10.1039/c6ta 0239 h) and the like uses iminodiacetic acid as a carbon source, ni (NO) 3 ) 2 As a metal source, self-assembled precursors are prepared under high temperature and high pressure conditions as well, and further thermally pyrolyzed under Ar atmosphere to prepare the carbon-coated nickel nanoparticles. Document RSC advance (2017,7,1531-1539) discloses a method of assembling a metal organic framework precursor (MOF) first at high temperature and high pressure using nitrogen-free organic ligands, followed by pyrolysis to synthesize a porous carbon-coated nano Ni composite. However, this method has disadvantages in that the preparation of the metal-organic framework material is complicated (high temperature and high pressure reaction is required in the reaction vessel), the productivity is low, and a large amount of organic solvent is used.
The aforementioned prior art has respective drawbacks. Therefore, CN109304201A and CN 109304476A develop a method with simpler process and lower cost, realize pure water phase, no organic solvent and prepare the precursor of the carbon-coated metal material at normal pressure; the method produces a composite material with carbon-coated metal core-shell structures distributed in a carbon matrix, wherein the mass fraction of carbon is approximately 20% to 60%.
With respect to Volatile Organic Compounds (VOCs), they generally refer to organic compounds having a saturated vapor pressure of about more than 70Pa at ordinary temperature and a boiling point of less than 260℃at ordinary pressure, such as alkanes, aromatic hydrocarbons, ether alcohols, halogenated hydrocarbons, and the like, as usual. In recent years, VOCs have become one of the main atmospheric pollutants in China, wherein alkane volatile organic compounds are considered to be the most stable and difficult to eliminate components in VOCs, and are largely generated in tail gas emission in petrochemical industries such as oil fields, refining factories and the like. For example, the waste gas generated in the process of producing maleic anhydride by the industrial n-butane oxidation method contains a large amount of n-butane, and in addition, liquefied petroleum gas is used in a large amount in industrial production as fuel, which also causes an increasing emission of lower alkanes such as propane and butane, which pose an increasing threat to human health and environment. How to control and eliminate the emission of VOCs, particularly low alkanes, is one of the hot spots of research in the environmental field. The catalytic combustion method has the advantages of high purification efficiency, no secondary pollution and the like, is one of the most effective methods for controlling and eliminating the emission of low-carbon alkane, and has the core of designing and preparing a high-performance catalyst. The research of taking the carbon-coated non-noble metal nano material as the catalyst in the field is still in the initial stage, and has important research value.
It is noted that the information disclosed in the foregoing background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known to a person of ordinary skill in the art.
Disclosure of Invention
The invention aims to overcome at least one defect of the prior art, and provides a carbon-coated nickel nanocomposite, a preparation method and application thereof, wherein the nanocomposite comprises a nuclear membrane structure with a graphitized carbon membrane and an elemental nickel core, has excellent activity as a catalyst, can efficiently catalyze low-carbon alkane to oxidize and burn at a lower temperature, has important significance in protecting the environment and reducing the atmospheric pollution, and has good industrial application prospect.
In order to achieve the above purpose, the present invention adopts the following technical scheme:
in one aspect, the present application provides a carbon-coated nickel nanocomposite having a core membrane structure with an outer membrane that is a graphitized carbon membrane and an inner core that is nickel nanoparticles, wherein the carbon content of the nanocomposite is greater than 0wt% and no greater than 5wt% of the nanocomposite, as determined according to elemental analysis methods.
In one embodiment, the carbon content is greater than 0wt% and no greater than 2wt%, preferably from 0.1 to 1.5wt%, more preferably from 0.6 to 1.1wt% of the nanocomposite.
In one embodiment, the carbon-coated nickel nanocomposite is non-pyrophoric in air.
In one embodiment, the ratio of the carbon element determined by X-ray photoelectron spectroscopy to the carbon element content determined by elemental analysis in the nanocomposite is not less than 10 in terms of mass ratio.
In one embodiment, the nanocomposite is located at 1580cm in raman spectrum -1 G peak intensity in the vicinity and at 1320cm -1 The ratio of nearby D peak intensities is greater than 2.
In one embodiment, the nanocomposite has a particle size of 1nm to 100nm.
In a second aspect, the present application provides a method of preparing a carbon-coated nickel nanocomposite of the present application, comprising the steps of:
putting a nickel-containing compound and a polybasic organic carboxylic acid into a solvent to be mixed to form a homogeneous solution;
removing the solvent in the homogeneous solution to obtain a precursor;
the precursor is pyrolyzed in an inert atmosphere or a reducing atmosphere;
carrying out oxygen treatment on the pyrolyzed product;
and (3) carrying out reduction treatment on the product after the oxygen treatment to obtain the nanocomposite.
In one embodiment, the oxygen treatment comprises introducing an oxygen treatment standard gas into the pyrolyzed product and heating, wherein the oxygen treatment standard gas comprises oxygen and balance gas, and the volume concentration of the oxygen is 10-40%.
In one embodiment, the temperature of the oxygen treatment is 200 ℃ to 500 ℃ and the time of the oxygen treatment is 0.5h to 10h.
In one embodiment, the reduction treatment comprises introducing a reduction treatment standard gas into the oxygen-treated product and heating, wherein the reduction treatment standard gas contains hydrogen and an equilibrium gas, and the volume concentration of the hydrogen is 0.5-100%.
In one embodiment, the temperature of the reduction treatment is 200-500 ℃, and the time of the reduction treatment is 0.5-10 h.
In one embodiment, the mass ratio of the nickel-containing compound to the polybasic organic carboxylic acid is 1 (0.1 to 100); the nickel-containing compound is selected from one or more of organic acid salt of nickel, nickel carbonate, basic nickel carbonate, nickel hydroxide and nickel oxide; the polybasic organic carboxylic acid is selected from one or more of citric acid, maleic acid, trimesic acid, terephthalic acid, gluconic acid and malic acid.
In one embodiment, the pyrolyzing comprises: heating the precursor to a constant temperature section in an inert atmosphere or a reducing atmosphere, and keeping the constant temperature in the constant temperature section;
the heating temperature rise rate is 0.5-30 ℃/min, the constant temperature section temperature is 400-800 ℃, the constant temperature time is 20-600 min, the inert atmosphere is nitrogen or argon, and the reducing atmosphere is the mixed gas of inert gas and hydrogen.
In a third aspect, the present application provides the use of the nanocomposite described herein above as a catalyst.
In a fourth aspect, the present application provides the use of the nanocomposite described herein above as a catalyst for catalytic oxidation with a reaction gas comprising a lower alkane and oxygen, the use comprising: the carbon-coated nickel composite material is used as a catalyst to contact with reaction gas for catalytic oxidation reaction; wherein the reaction gas contains low-carbon alkane and oxygen, and the low-carbon alkane is selected from one or more of C1-C4 alkane compounds.
According to one embodiment of the invention, the catalytic oxidation reaction is carried out at a temperature of 250℃to 400 ℃.
According to one embodiment of the invention, the reaction space velocity is between 1000 and 5000 ml of reaction gas/(hour g of nanocomposite).
According to one embodiment of the invention, the content of the low-carbon alkane in the reaction gas is 0.01-2% by volume, and the content of the oxygen is 5-20% by volume.
According to the technical scheme, the carbon-coated nickel nanocomposite and the preparation method and application thereof provided by the invention have the advantages and positive effects that:
in a fifth aspect, the present application provides the use of the nanocomposite described herein above as a catalyst for catalytic hydrogenation with an organic compound; wherein the organic compound is selected from one or more of p-chloronitrobenzene, nitrobenzene, nitrophenol, nitroanisole, phenol, olefin, aromatic hydrocarbon, aldehyde and ketone.
The carbon-coated nickel nanocomposite provided by the invention comprises a nuclear membrane structure with a graphitized carbon membrane and a nickel core, has excellent activity as a catalyst through a unique structure and composition, can efficiently catalyze low-carbon alkane in reaction gas to oxidize and burn at a lower temperature, has important significance in protecting environment and reducing atmospheric pollution, and has good industrial application prospect.
Drawings
The following drawings are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate the invention and together with the description serve to explain the invention, without limitation to the invention.
FIG. 1 is an X-ray diffraction pattern of the nanocomposite of example 1;
FIG. 2 is a transmission electron microscope image of the nanocomposite of example 1;
FIG. 3 is a Raman spectrum of the nanocomposite of example 1;
FIG. 4 is an X-ray diffraction pattern of the nanocomposite of example 2;
FIG. 5 is a transmission electron microscope image of the nanocomposite of example 2;
FIG. 6 is a Raman spectrum of the nanocomposite of example 2.
Detailed Description
The technical scheme of the invention is further described below according to specific embodiments. The scope of the invention is not limited to the following examples, which are given for illustrative purposes only and do not limit the invention in any way.
The following provides various embodiments or examples to enable those skilled in the art to practice the invention as described herein. These are, of course, merely examples and are not intended to limit the invention from that described. The endpoints of the ranges and any values disclosed in the present invention are not limited to the precise range or value, and the range or value should be understood to include values close to the range or value. For numerical ranges, one or more new numerical ranges may be found between the endpoints of each range, between the endpoint of each range and the individual point value, and between the individual point value, in combination with each other, and should be considered as specifically disclosed herein.
Any terms not directly defined herein should be construed to have the 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 term "nuclear membrane structure" in the present invention refers to a nuclear membrane structure having an outer membrane, which is a graphitized carbon membrane, and an inner core comprising nickel nanoparticles. The composite material formed by coating the graphitized carbon film with the nickel nano particles is spherical or spheroidic.
The term "graphitized carbon film" refers to a thin film structure composed mainly of graphitized carbon.
The term "carbon element content determined by X-ray photoelectron spectroscopy (XPS)" refers to the relative content of carbon elements on the surface of a material, which is measured by performing element quantitative analysis by using an X-ray photoelectron spectrometer as an analysis tool. XPS mainly measures the carbon element content of the surface phase.
The term "carbon element content determined in elemental analysis" refers to the relative content of total carbon elements of a material as measured by elemental quantitative analysis using an elemental analyzer as an analysis tool. The total content of carbon element in the material relative to the whole material can be determined by adopting an elemental analysis method.
In a first aspect, the present invention provides a carbon-coated nickel nanocomposite having a core membrane structure with an outer membrane being a graphitized carbon membrane and an inner core being nickel nanoparticles, wherein the carbon content is no more than 5wt% of the nanocomposite. In some embodiments, the carbon content is no greater than 2wt% of the nanocomposite. For example, may be about 0.1-2wt%; preferably less than about 1.5wt%, for example, may be about 0.1 to 1.5wt%, about 0.2 to 1.4wt%, 0.3 to 1.3wt%, 0.4 to 1.2wt%, 0.6 to 1.1wt%, 0.6 to 1.0wt%, etc. In this application, the carbon content is determined using elemental analysis methods.
According to the invention, the carbon-coated nickel nanocomposite is a nuclear membrane structure comprising an outer membrane layer and an inner core layer, wherein the outer membrane is mainly composed of graphitized carbon membranes, and the graphitized carbon membranes are thin-film structures mainly composed of graphitized carbon and are coated on the surfaces of nickel nanoparticles.
In some embodiments, the ratio of elemental carbon determined by X-ray photoelectron spectroscopy to elemental carbon content determined by elemental analysis in the nanocomposite of the invention is not less than 10. As described above, the carbon element content determined by the X-ray photoelectron spectroscopy refers to the relative content of carbon element on the surface of the material measured by performing elemental quantitative analysis using the X-ray photoelectron spectrometer as an analysis tool. The carbon element content determined in the elemental analysis refers to the relative content of the total carbon element of the material measured by elemental quantitative analysis using an elemental analyzer as an analysis tool. When the ratio of the carbon element determined by the X-ray photoelectron spectroscopy to the carbon element content determined by the elemental analysis is larger, the fact that most of carbon is concentrated on the surface of the material in the whole nano composite material is shown, a carbon film layer is formed, and the nuclear film structure is further formed.
In some embodiments, the nanocomposite of the present invention is located at 1580cm in raman spectra -1 G peak intensity in the vicinity and at 1320cm -1 The ratio of nearby D peak intensities is greater than 2. As known to those skilled in the art, the D peak and the G peak are Raman characteristic peaks of C atom crystals, the D peak represents a defect of a carbon atom lattice, and the G peak represents a C atom sp 2 Hybrid in-plane stretching vibration. It is known in the art that the greater the ratio of G-peak intensity to D-peak intensity, the more graphitic carbon is present in the nanocomposite compared to amorphous carbon. That is, the carbon element in the nanocomposite of the present invention exists mainly in the form of graphitic carbon. The graphite carbon has better oxidation resistance, and can synergistically increase catalytic activity with nickel nano particles of the inner core, thereby improving the performance of the whole composite material.
In some embodiments, the particle size of the aforementioned nuclear membrane structures is generally in the range of 1nm to 100nm, preferably 2nm to 40nm.
The second aspect of the present invention also provides a method for preparing the aforementioned carbon-coated nickel nanocomposite, comprising the steps of:
putting a nickel-containing compound and a polybasic organic carboxylic acid into a solvent to be mixed to form a homogeneous solution;
removing the solvent in the homogeneous solution to obtain a precursor;
pyrolyzing the precursor in an inert atmosphere or a reducing atmosphere;
the products after pyrolysis are subjected to oxygen treatment,
the product after the oxygen treatment is subjected to reduction treatment,
obtaining the nano composite material.
Specifically, the precursor may be a water-soluble mixture, which is a mixture containing nickel obtained by dissolving a nickel-containing compound and a polyvalent organic carboxylic acid in a solvent such as water or ethanol to form a homogeneous solution, and then directly evaporating the solvent to remove the solvent. The aforementioned temperature and process of evaporating the solvent may be any available prior art technique, for example, spray drying at 80-120 ℃, or drying in an oven.
In addition, other organic compounds than the two above may be added together to form a homogeneous solution, and the other organic compounds may be any organic compound that can supplement the carbon source required in the product and that does not contain other doping atoms. Organic compounds which are not volatile, such as organic polyols, lactic acid, etc., are preferred.
In some embodiments, the mass ratio of nickel-containing compound, polybasic organic carboxylic acid and other organic compounds is 1:0.1 to 10:0 to 10, preferably 1:0.5 to 5:0 to 5, more preferably 1:0.8 to 3:0 to 3; the nickel-containing compound is one or more of organic acid salt of nickel, nickel carbonate, basic nickel carbonate, nickel hydroxide and nickel oxide; preferably, the organic acid salt is a nickel organic carboxylic acid salt containing no other heteroatoms. The polybasic organic carboxylic acid is selected from one or more of citric acid, maleic acid, trimesic acid, terephthalic acid, gluconic acid and malic acid.
In some embodiments, the pyrolyzing comprises: heating the precursor to a constant temperature section in an inert atmosphere or a reducing atmosphere, and keeping the constant temperature in the constant temperature section;
wherein the heating rate is 0.5-30 ℃/min, preferably 1-10 ℃/min; the temperature of the constant temperature section is 400-800 ℃, preferably 500-800 ℃; the constant temperature time is 20 min-600 min, preferably 60 min-480 min; the inert atmosphere is nitrogen or argon, the reducing atmosphere is a mixed gas of inert gas and hydrogen, for example, a small amount of hydrogen is doped in the inert atmosphere.
In some embodiments, the oxygen treatment comprises introducing an oxygen treatment standard gas into the pyrolyzed product and heating, wherein the oxygen treatment standard gas comprises oxygen and an equilibrium gas, and the volume concentration of oxygen is 10% -40%, alternatively 10% -30%. The balance gas may be an inert gas such as nitrogen or argon, but the present invention is not limited thereto.
In some embodiments, the temperature of the oxygen treatment is 200 ℃ to 500 ℃, preferably 300 ℃ to 400 ℃; the oxygen treatment time is 0.5 h-10 h.
In some embodiments, the reduction treatment comprises introducing a reduction treatment standard gas into the oxygen treated product and heating, wherein the reduction treatment standard gas comprises hydrogen and an equilibrium gas, and the hydrogen has a volume concentration of 0.5% -100%. The balance gas may be an inert gas such as nitrogen or argon, but the present invention is not limited thereto.
In some embodiments, the temperature of the reduction treatment is 200-500 ℃, and the time of the reduction treatment is 0.5-10 h, and then the carbon-coated nickel nanocomposite of the invention can be obtained.
The inventors of the present application found that the carbon-coated nickel nanocomposite of the present invention, after oxygen treatment and reduction treatment, is greatly different in structure and performance from the pyrolyzed product: compared with the products in CN109304201A and CN 109304476A, the composite material of the invention has the main component of nickel, a carbon film which has very low carbon content and is basically graphitized, a large amount of amorphous carbon matrix is not existed, and a very thin graphitized carbon layer is coated outside nano-level elementary nickel particles, so that the nano-level elementary nickel particles show higher catalytic activity and stability than pure nickel, thereby providing a catalytic active component which is more efficient than pure nickel. The carbon-coated elemental nickel composite material provided by the invention eliminates the possible limit of a carbon matrix which is inevitably generated in the manufacturing process on the catalytic performance, so that the carbon-coated elemental nickel composite material can be more flexibly applied to various catalytic reactions.
In the carbon-coated nickel nanocomposites of the invention, as characterized by Raman spectroscopy (at 1580cm -1 G peak intensity in the vicinity and at 1320cm -1 The ratio of nearby D peak intensities is greater than 2) that is substantially free of amorphous carbon matrix, with only a core-shell structure of graphitic carbon-coated metal simple substance. The main component of the carbon-coated nickel nanocomposite material is nickel, so that the carbon-coated nickel nanocomposite material can be larger than the magnetization coefficient X0 and can be used in wider magnetic field application environments. The specific magnetization coefficient X0 is the magnetic moment generated by a substance of a unit mass in an external magnetic field of a unit strength, and can more precisely represent the magnetism of an object.
A third aspect of the present invention provides the use of the nanocomposite described above as a catalyst. That is, the nanocomposite of the present invention has catalytic activity, and can be used as a catalyst in various industrial production reactions.
In a fourth aspect, the present invention provides the use of the nanocomposite as described above as a catalyst for catalytic oxidation with a reaction gas comprising a lower alkane and oxygen, the use comprising: the carbon-coated nickel composite material is used as a catalyst to contact with reaction gas for catalytic oxidation reaction; wherein the reaction gas contains low-carbon alkane and oxygen, and the low-carbon alkane is selected fromC 1 ~C 4 One or more of the alkanes.
In one embodiment, the catalytic oxidation conditions include: the temperature is 250-400 ℃, and the reaction space velocity is 1000-5000 ml of reaction gas/(hour-gram of nano composite material); in the reaction gas, the content of the low-carbon alkane is 0.01-2% by volume, and the content of the oxygen is 5-20% by volume.
The invention will be further illustrated by the following examples, but the invention is not limited thereby. Unless otherwise indicated, all reagents used in the present invention were analytically pure.
The invention detects the elements on the surface of the material by an X-ray photoelectron spectroscopy (XPS). The X-ray photoelectron spectroscopy analyzer used was an ESCALab220i-XL type radiation electron spectroscopy manufactured by VG scientific company and equipped with Avantage V5.926 software, and the X-ray photoelectron spectroscopy analysis test conditions were: the excitation source is monochromized A1K alpha X-ray with power of 330W and basic vacuum of 3X 10 during analysis and test -9 mbar。
Analysis of carbon (C) was performed on a Elementar Micro Cube elemental analyzer, which was used mainly for analysis of four elements, carbon (C), hydrogen (H), oxygen (O), and nitrogen (N), with the following specific methods and conditions: 1 mg-2 mg of sample is weighed in a tin cup, is put into an automatic sample feeding disc, enters a combustion tube through a ball valve for combustion, the combustion temperature is 1000 ℃ (in order to remove atmospheric interference during sample feeding, helium is adopted for blowing), and then reduction copper is used for reducing the burnt gas 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 analysis of oxygen element is to convert oxygen in the sample into CO by pyrolysis under the action of a carbon catalyst, and then detect the CO by TCD. Since the composite material of the present invention contains only carbon and metallic nickel, the total content of metallic nickel can be determined from the content of carbon element.
The content of the metal element is calculated by subtracting the content of the carbon element from the material.
The Raman detection of the invention adopts a LabRAM HR UV-NIR laser confocal Raman spectrometer manufactured by HORIBA company of Japan, and the laser wavelength is 325nm.
The model of the high-resolution transmission electron microscope (HRTEM) adopted by the invention is JEM-2100 (HRTEM) (Japanese electronics Co., ltd.) and the test conditions of the high-resolution transmission electron microscope are as follows: the acceleration voltage was 200kV.
The model of the XRD diffractometer adopted by the invention is XRD-6000 type X-ray powder diffractometer (Shimadzu), and XRD testing conditions are as follows: cu target, ka radiation (wavelength λ=0.154 nm), tube voltage 40kV, tube current 200mA, scan speed 10 ° (2θ)/min.
Example 1
This example illustrates the preparation of the carbon-coated nickel nanocomposite of the present invention.
(1) 10g of nickel carbonate and 10g of citric acid are weighed into a beaker containing 100mL of deionized water, stirred at 70 ℃ to obtain a homogeneous solution, and continuously heated and evaporated to dryness to obtain a solid precursor.
(2) And (3) placing the solid precursor obtained in the step (1) in a porcelain boat, placing the porcelain boat in a constant temperature area of a tube furnace, introducing nitrogen with the flow of 100mL/min, heating to 600 ℃ at the speed of 4 ℃/min, keeping the temperature for 2 hours, stopping heating, and cooling to room temperature under the nitrogen atmosphere to obtain black solid.
(3) Placing the black solid obtained in the step (2) in a porcelain boat, then placing the porcelain boat in a constant temperature area of a tube furnace, introducing standard gas (15% of oxygen and 15% of nitrogen are balance gas) with the flow rate of 100mL/min, heating to 350 ℃ at the speed of 2 ℃/min, keeping the temperature for 8 hours, stopping heating, and cooling to room temperature under the atmosphere of the standard gas to obtain the black solid.
(4) Placing the black solid obtained in the step (3) in a porcelain boat, then placing the porcelain boat in a constant temperature area of a tube furnace, introducing standard gas (80% of hydrogen and 80% of nitrogen are balance gas) with the flow rate of 100mL/min, heating to 230 ℃ at the speed of 2 ℃/min, keeping the temperature for 3 hours, stopping heating, and cooling to room temperature under the atmosphere of the standard gas to obtain the black solid, namely the nanocomposite material.
Characterization of materials:
fig. 1 shows an X-ray diffraction pattern (XRD) of the nanocomposite of example 1, and it is apparent from fig. 1 that nickel in the nanocomposite is present as elemental nickel after the reduction treatment. Fig. 2 is a Transmission Electron Microscope (TEM) image of the nanocomposite of example 1, and it was observed that the material had a carbon layer film on the surface, and the particle size was approximately 5 to 20 nm.
The elemental analysis revealed that the carbon content was 0.79 wt% and the nickel content was 99.21 wt% in the nanocomposite. As is known from X-ray photoelectron spectroscopy (XPS) analysis, the ratio of the carbon element content of the surface layer to the total carbon element content of the nanocomposite is 28.4/1. It can be seen that the carbon in the nanocomposite is mainly present at the surface of the nuclear membrane structure. FIG. 3 shows a Raman spectrum of the nanocomposite, wherein the G peak (1580 cm -1 ) Intensity of (C) and intensity of D peak (1320 cm) -1 ) The ratio of (2.1/1). It can be seen that the carbon in this material is mostly graphitic carbon.
The nanocomposite of this example was not pyrophoric in air.
Example 2
This example illustrates the preparation of the carbon-coated nickel nanocomposite of the present invention.
(1) 10g of nickel acetate and 10g of citric acid are weighed into a beaker containing 100mL of deionized water, stirred at 70 ℃ to obtain a homogeneous solution, and continuously heated and evaporated to dryness to obtain a solid precursor.
(2) And (3) placing the solid precursor obtained in the step (1) in a porcelain boat, placing the porcelain boat in a constant temperature area of a tube furnace, introducing nitrogen with the flow of 100mL/min, heating to 650 ℃ at the speed of 2 ℃/min, stopping heating after keeping the temperature for 2 hours, and cooling to room temperature under the nitrogen atmosphere to obtain black solid.
(3) Placing the black solid obtained in the step (2) in a porcelain boat, then placing the porcelain boat in a constant temperature area of a tube furnace, introducing standard gas (15% of oxygen and 15% of nitrogen are balance gas) with the flow rate of 100mL/min, heating to 330 ℃ at the speed of 2 ℃/min, keeping the temperature for 8 hours, stopping heating, and cooling to room temperature under the atmosphere of the standard gas to obtain the black solid.
(4) Placing the black solid obtained in the step (3) in a porcelain boat, then placing the porcelain boat in a constant temperature area of a tube furnace, introducing standard gas (80% of hydrogen and 80% of nitrogen are balance gas) with the flow rate of 100mL/min, heating to 230 ℃ at the speed of 2 ℃/min, keeping the temperature for 3 hours, stopping heating, and cooling to room temperature under the atmosphere of the standard gas to obtain the black solid, namely the nanocomposite material.
Characterization of materials:
fig. 4 shows the X-ray diffraction pattern of the nanocomposite of example 2, and it can be seen from fig. 4 that the nickel in the nanocomposite is present as elemental nickel after the reduction treatment. Fig. 5 shows a transmission electron microscope image of the nanocomposite of example 2, and it can be observed that the material surface has a carbon layer film with a particle size of about 5 to 20 nm.
Elemental analysis revealed that the carbon content was 0.94 wt% and the nickel content was 99.06 wt% in the nanocomposite. As is known from X-ray photoelectron spectroscopy (XPS) analysis, the ratio of the surface layer carbon element content to the total carbon element content of the nanocomposite material is 24.3/1. It can be seen that the carbon in the nanocomposite is mainly present at the surface of the nuclear membrane structure. FIG. 6 shows a Raman spectrum of the nanocomposite, wherein the G peak (1580 cm -1 ) Intensity of (C) and intensity of D peak (1320 cm) -1 ) The ratio of (2.3/1). It can be seen that the carbon in this material is mostly graphitic carbon.
The nanocomposite of this example was not pyrophoric in air.
Application example 1
This application example is for illustrating the reaction of catalyzing and oxidizing n-butane using the nanocomposite of example 1 as a catalyst.
0.2g of catalyst is placed in a continuous flow fixed bed reactor, the composition of reaction gas is n-butane with the volume percentage content of 0.5% and oxygen with the volume percentage content of 8.0%, nitrogen is balance gas, the flow rate of the reaction gas is 15ml/min, the activity evaluation temperature range is shown in table 1, and the conversion rate of the catalyst for catalytic combustion of VOCs at different temperatures is shown in table 1.
Application example 2
The reaction for catalytic oxidation of n-butane was carried out by the method of application example 1, except that the nanocomposite of example 2 was used as a catalyst, and the results are shown in Table 1.
Comparative application example
The reaction for catalytic oxidation of n-butane was carried out by the method of application example 1, except that a commercial platinum-based catalyst (manufacturer: seventh to eighth institute of Marine heavy industry group Co., china, production number: WJX-001) was used as a comparative example, and the results are shown in Table 1.
TABLE 1
Figure BDA0002990190090000121
Figure BDA0002990190090000131
In the catalytic oxidation technology of low-carbon alkane, supported noble metal catalysts such as Pt and Pd are most commonly used. As can be seen from Table 1, although the commercial platinum-based catalyst used in the comparative example has better catalytic performance in the reaction of catalyzing and oxidizing n-butane, the temperature of catalyzing and oxidizing n-butane is higher than 350 ℃ under laboratory conditions, and the carbon-coated nickel nanocomposite prepared by the method has better performance of catalyzing and oxidizing low-carbon alkane, can efficiently catalyze n-butane to oxidize and burn to generate carbon dioxide and water at relatively low temperature, greatly reduces the cost of the catalyst, the reaction temperature and the energy consumption, and has good industrial application prospect.
In addition, compared with the carbon-coated material which is not subjected to oxygen treatment and reduction treatment, the carbon-coated nickel nanocomposite prepared by the method has the following advantages: the carbon-coated nickel nanocomposite of the invention is basically free of amorphous carbon matrix, has only a core-shell structure of graphite carbon-coated metal simple substance, has higher metal content and larger specific magnetization coefficient X0, is suitable for occasions without adverse effects of amorphous carbon matrix or amorphous carbon matrix, and has wider application.
It will be appreciated by persons skilled in the art that the embodiments described herein are merely exemplary and that various other alternatives, modifications and improvements may be made within the scope of the invention. Thus, the present invention is not limited to the above-described embodiments, but only by the claims.

Claims (13)

1. A carbon-coated nickel nanocomposite is characterized in that the nanocomposite has a nuclear membrane structure of an outer membrane and an inner core, the outer membrane is a graphitized carbon membrane, the inner core is nickel nanoparticles, wherein the carbon content of the nanocomposite is 0.6-1.1wt% of the nanocomposite in terms of mass percent, the ratio of carbon element determined by X-ray photoelectron spectroscopy to carbon element determined by elemental analysis in the nanocomposite is not less than 10, and the nanocomposite is located at 1580cm in Raman spectrum -1 G peak intensity in the vicinity and at 1320cm -1 The ratio of nearby D peak intensities is greater than 2.
2. The nanocomposite of claim 1, wherein the nanocomposite has a particle size of 1nm to 100nm.
3. A method of preparing the carbon-coated nickel nanocomposite of claim 1 or 2, comprising the steps of:
putting a nickel-containing compound and a polybasic organic carboxylic acid into a solvent to be mixed to form a homogeneous solution;
removing the solvent in the homogeneous solution to obtain a precursor;
the precursor is pyrolyzed in an inert atmosphere or a reducing atmosphere;
carrying out oxygen treatment on the pyrolyzed product;
and (3) carrying out reduction treatment on the product after the oxygen treatment to obtain the nanocomposite.
4. The method according to claim 3, wherein the oxygen treatment comprises introducing an oxygen treatment standard gas into the pyrolyzed product and heating, wherein the oxygen treatment standard gas contains oxygen and balance gas, and the volume concentration of the oxygen is 10% -40%.
5. The method according to claim 3, wherein the temperature of the oxygen treatment is 200-500 ℃ and the time of the oxygen treatment is 0.5-10 h.
6. The method according to claim 3, wherein the reduction treatment comprises introducing a standard reduction treatment gas into the oxygen-treated product and heating the product, wherein the standard reduction treatment gas is hydrogen and an optional balance gas, and the volume concentration of the hydrogen is 0.5% -100%.
7. The method according to claim 3, wherein the temperature of the reduction treatment is 200-500 ℃ and the time of the reduction treatment is 0.5-10 h.
8. The method according to claim 3, wherein the mass ratio of the nickel-containing compound to the polybasic organic carboxylic acid is 1 (0.1-100); the nickel-containing compound is selected from one or more of organic acid salt of nickel, nickel carbonate, basic nickel carbonate, nickel hydroxide and nickel oxide; the polybasic organic carboxylic acid is selected from one or more of citric acid, maleic acid, trimesic acid, terephthalic acid, gluconic acid and malic acid.
9. A method of preparing according to claim 3, wherein the pyrolyzing comprises: heating the precursor to a constant temperature section in an inert atmosphere or a reducing atmosphere, and keeping the constant temperature in the constant temperature section;
the heating temperature rise rate is 0.5-30 ℃/min, the constant temperature section temperature is 400-800 ℃, the constant temperature time is 20-600 min, the inert atmosphere is nitrogen or argon, and the reducing atmosphere is a mixed gas of inert gas and hydrogen.
10. Use of the nanocomposite according to claim 1 or 2 as a catalyst.
11. Use of the nanocomposite according to claim 1 or 2 as a catalyst for catalytic oxidation with a reaction gas comprising low-carbon alkanes and oxygen, the use comprising: the nano composite material of the carbon-coated nickel is used as a catalyst to be contacted with reaction gas for catalytic oxidation reaction; the reaction gas contains low-carbon alkane and oxygen, wherein the low-carbon alkane is selected from one or more of C1-C4 alkane compounds.
12. The use of claim 11, wherein the conditions of catalytic oxidation comprise: the temperature is 250-400 ℃, and the reaction space velocity is 1000-5000 ml of reaction gas/(hour.g of nanocomposite); in the reaction gas, the content of the low-carbon alkane is 0.01-2% by volume, and the content of the oxygen is 5% -20% by volume.
13. Use of the nanocomposite according to claim 1 or 2 as a catalyst for catalytic hydrogenation with organic compounds; wherein the organic compound is selected from one or more of p-chloronitrobenzene, nitrobenzene, nitrophenol, nitroanisole, phenol, olefin, aromatic hydrocarbon, aldehyde and ketone.
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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105032424A (en) * 2015-06-05 2015-11-11 中国科学院化学研究所 Catalyst for selective hydrogenation reaction of aromatic nitrocompound and preparation method of catalyst
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
CN109304476A (en) * 2017-07-28 2019-02-05 中国石油化工股份有限公司 Carbon coating transition metal nanocomposite and its preparation method and application

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105032424A (en) * 2015-06-05 2015-11-11 中国科学院化学研究所 Catalyst for selective hydrogenation reaction of aromatic nitrocompound and preparation method of catalyst
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
CN109304476A (en) * 2017-07-28 2019-02-05 中国石油化工股份有限公司 Carbon coating transition metal nanocomposite and its preparation method and application
CN109304475A (en) * 2017-07-28 2019-02-05 中国石油化工股份有限公司 Carbon-coating nickel composite material and preparation method
CN109304178A (en) * 2017-07-28 2019-02-05 中国石油化工股份有限公司 A kind of synthetic method of alkane derivative

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
Facile synthesis of N-doped carbon-coated nickel oxide nanoparticle sembedde d in N-doped carbon sheets for reversible lithium storage;Zhiqing Jia等;Journal of Alloys and Compounds;第745卷;第147-154页 *

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