CN110368951B - High-efficiency nitrogen reduction cobalt manganese oxide catalyst and preparation method thereof - Google Patents

High-efficiency nitrogen reduction cobalt manganese oxide catalyst and preparation method thereof Download PDF

Info

Publication number
CN110368951B
CN110368951B CN201910600630.5A CN201910600630A CN110368951B CN 110368951 B CN110368951 B CN 110368951B CN 201910600630 A CN201910600630 A CN 201910600630A CN 110368951 B CN110368951 B CN 110368951B
Authority
CN
China
Prior art keywords
alloy
manganese oxide
oxide catalyst
alloy strip
cobalt
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN201910600630.5A
Other languages
Chinese (zh)
Other versions
CN110368951A (en
Inventor
朱胜利
肖�琳
崔振铎
梁砚琴
杨贤金
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Tianjin University
Original Assignee
Tianjin University
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Tianjin University filed Critical Tianjin University
Priority to CN201910600630.5A priority Critical patent/CN110368951B/en
Publication of CN110368951A publication Critical patent/CN110368951A/en
Application granted granted Critical
Publication of CN110368951B publication Critical patent/CN110368951B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
    • B01J23/002—Mixed oxides other than spinels, e.g. perovskite
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
    • B01J23/70—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper
    • B01J23/76—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
    • B01J23/84—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 arsenic, antimony, bismuth, vanadium, niobium, tantalum, polonium, chromium, molybdenum, tungsten, manganese, technetium or rhenium
    • B01J23/889—Manganese, technetium or rhenium
    • B01J23/8892—Manganese
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
    • C25B1/00—Electrolytic production of inorganic compounds or non-metals
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
    • C25B11/00—Electrodes; Manufacture thereof not otherwise provided for
    • C25B11/04—Electrodes; Manufacture thereof not otherwise provided for characterised by the material
    • C25B11/051—Electrodes formed of electrocatalysts on a substrate or carrier
    • C25B11/073—Electrodes formed of electrocatalysts on a substrate or carrier characterised by the electrocatalyst material
    • C25B11/091—Electrodes formed of electrocatalysts on a substrate or carrier characterised by the electrocatalyst material consisting of at least one catalytic element and at least one catalytic compound; consisting of two or more catalytic elements or catalytic compounds

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Organic Chemistry (AREA)
  • Electrochemistry (AREA)
  • Metallurgy (AREA)
  • Inorganic Chemistry (AREA)
  • Catalysts (AREA)

Abstract

The invention provides a high-efficiency nitrogen reduction cobalt manganese oxide catalyst and a preparation method thereof, wherein the preparation method comprises the steps of preparing materials according to the atom percent of pure aluminum of 70-80%, the atom percent of pure cobalt of 10-20% and the atom percent of pure manganese of 10-20%, smelting the materials by an electric arc smelting furnace in the atmosphere of inert protective gas to obtain an Al-Co-Mn alloy ingot, preparing the Al-Co-Mn alloy ingot into an Al-Co-Mn alloy strip by a strip throwing machine, placing the Al-Co-Mn alloy strip in NaOH solution to remove Al in the Al-Co-Mn alloy strip, then placing the Al-Co-Mn alloy strip in a tubular furnace, heating to 280 ℃ at the heating rate of 3-9 ℃/min, preserving heat for 1-5h, naturally cooling to the room temperature of 20-25 ℃ to obtain the cobalt manganese oxide catalyst, wherein the cobalt manganese oxide catalyst is prepared from CoO and Mn3O4And (4) forming. The catalyst improves the nitrogen reduction yield and the Faraday efficiency and maintains the stability for a long time from the viewpoint of saving the cost.

Description

High-efficiency nitrogen reduction cobalt manganese oxide catalyst and preparation method thereof
Technical Field
The invention relates to the technical field of electrode catalytic materials, in particular to a high-efficiency nitrogen reduction cobalt manganese oxide catalyst and a preparation method thereof.
Background
NH3The function in the earth ecosystem is vital, and the hydrogen storage fuel is widely applied to industry and agriculture. Nitrogen reduction was mainly derived from nitrogenase enzymes in microorganisms before the 20 th century. In 1950, Haber and Bosch invented a complex N2Is reduced to
Figure BDA0002119170010000011
The process requires high pressure (100 atm) at high temperature (700K) and H2Etc., and carbon dioxide is produced to cause global warming. Thus, at ambient temperature and pressure, N is electrocatalytically converted2Reduction to NH3Is very important. However, electrochemical Nitrogen reduction (NRR) has been challenged to break stable N ≡ N and improve catalytic activity.
At present, transition metals and their composite materials are receiving wide attention in the field of nitrogen reduction electrocatalysis, including oxides, sulfides, phosphides, carbides, nitrides and the like. The problems of low yield of synthetic ammonia and low Faraday Efficiency (FE) of the nitrogen reduction catalyst are urgently solved, so that the low-cost and high-efficiency nitrogen reduction catalyst is developed, is suitable for social development, and has extremely important significance.
Disclosure of Invention
The invention overcomes the defects in the prior art, and the problems of low yield of synthetic ammonia and low Faraday efficiency of the existing nitrogen reduction catalyst, and provides a high-efficiency nitrogen reduction cobalt manganese oxide catalyst and a preparation method thereof.
The purpose of the invention is realized by the following technical scheme.
A high-efficiency nitrogen reduction cobalt manganese oxide catalyst and a preparation method thereof are carried out according to the following steps:
step 1, preparing Al-Co-Mn alloy strip
Proportioning 70-80% of pure aluminum, 10-20% of pure cobalt, 10-20% of pure manganese and 100% of the total atomic percentage of the three components, smelting the mixture in an arc smelting furnace in an inert protective gas atmosphere for 120-240s to repeatedly smelt Al-Co-Mn alloy ingots with uniform components, removing surface scale of the Al-Co-Mn alloy ingots, placing the Al-Co-Mn alloy ingots in a quartz tube with a small hole at the bottom end, pumping a strip thrower to vacuum, filling inert protective gas, heating by eddy current generated by an inductance coil to melt the alloy, pressing down an injection key after the alloy is completely melted, and spraying alloy liquid on a copper roller rotating at high speed from a nozzle of the quartz tube under the action of pressure difference between the upper part and the bottom part of the quartz tube to obtain an alloy strip, and cutting the alloy strip into sections with the length of 2-3cm and the width of 1-2cm, putting the sections into a beaker, ultrasonically treating and cleaning the sections by absolute ethyl alcohol, and drying the sections in a vacuum drying oven at the temperature of 20-25 ℃ to obtain the Al-Co-Mn alloy strip.
In step 1, the atomic percent of pure aluminum is 80%, the atomic percent of pure cobalt is 13-14%, and the atomic percent of pure manganese is 6-7%.
In the step 1, high-purity metal raw materials (the purity is higher than 99.9 wt%, namely the purity of the simple aluminum substance, the purity of the simple cobalt substance and the purity of the simple manganese substance are all more than or equal to 99.9 wt%) are selected for batching, and for active and easily oxidized metal raw materials, the surfaces of the active and easily oxidized metal raw materials are polished by using sand paper to remove oxide films of the active and easily oxidized metal raw materials, and then the active and easily oxidized metal raw materials are cleaned and then batched.
In step 1, the inert shielding gas is nitrogen, helium or argon.
In step 1, before melting, the degree of vacuum is evacuated to 1X 10-1Pa below, vacuum degree of smelting of 2.0-3.0 × 10-3Pa below, the smelting time is 160-200 s.
In the step 1, after smelting, each alloy ingot is turned over by a turning spoon to be remelted, and the smelting frequency of each alloy ingot is not less than five times.
In step 1, the conditions for preparing the Al-Co-Mn alloy strip are as follows: vacuum degree of 1X 10-2Pa below, the rotation speed of the copper roller is 2500-.
Step 2, preparing cobalt manganese oxide catalyst
Placing the Al-Co-Mn alloy strip prepared in the step 1 in NaOH solution to remove Al in the Al-Co-Mn alloy strip, then placing the Al-Co-Mn alloy strip in a tube furnace, heating to 280 ℃ for 650 ℃ at a heating rate of 3-9 ℃/min, preserving heat for 1-5h, and naturally cooling to room temperature of 20-25 ℃ to obtain the cobalt-manganese oxide catalyst, wherein the cobalt-manganese oxide catalyst is prepared from CoO and Mn3O4And (4) forming.
In the step 2, the Al-Co-Mn alloy strip is placed in 0.5-5M NaOH solution at the room temperature of 20-25 ℃ to react for 12-48h until no gas is generated, and after cleaning and drying, the alloy strip is mixed with 1-2M NaOH solution again and placed in a closed container to react for 12-48h in a constant temperature drying oven at the temperature of 25-60 ℃ until no gas is generated.
In the step 2, the temperature rise rate of the tubular furnace is 4-8 ℃/min, the heat preservation temperature is 300-.
The invention has the beneficial effects that: the cobalt-manganese oxide catalyst prepared by the method has a nano-sheet and nano-flower structure, and the specific surface area of the catalyst is increased, so that the number of exposed catalytic active sites is increased, and the overall catalytic activity is increased; by adding Mn element, the compound has a certain inhibiting effect on HER, can effectively improve Faraday efficiency, and further improves ammonia yield; when Al is removed by using chemical dealloying, cobalt manganese oxide is formed, and compared with a single oxide, the two oxides generate a certain synergistic effect during nitrogen reduction, so that the nitrogen reduction performance is improved to a certain extent; the cobalt manganese oxide is formed by placing the Al-Co-Mn alloy strip in an alkaline solution chemical dealloying process, and the operation method is simple and controllable.
Drawings
FIG. 1 is an SEM image of a nanosheet structure of a cobalt manganese oxide catalyst prepared in example 1 of the present invention before and after heat treatment;
FIG. 2 is a TEM image of a cobalt manganese oxide catalyst of example 1 after heat treatment;
FIG. 3 is an XRD pattern of a cobalt manganese oxide catalyst prepared in example 1 of the present invention after heat treatment;
FIG. 4 is a Raman graph of cobalt manganese oxide catalyst prepared according to example 1 of the present invention;
FIG. 5 is a graph of absorbance measurements performed after the cobalt manganese oxide catalyst has been subjected to nitrogen reduction tests at different potentials after being subjected to dealloying and heat treatment, and after having been subjected to indigo color development in accordance with an embodiment of the present invention;
FIG. 6 is a graph showing the absorbance at different potentials after the nitrogen reduction test of the cobalt manganese oxide catalyst prepared in example 1 of the present invention;
FIG. 7 is a graph of the nitrogen reduction performance of cobalt manganese oxide catalysts prepared in example 1 of the present invention in a proton exchange membrane isolated H-cell.
Detailed Description
The technical solution of the present invention is further illustrated by the following specific examples.
Example 1
Step 1, taking 9.7806g of pure aluminum (Al), 3.5516g of pure cobalt (Co) and 1.6678g of pure manganese (Mn), wherein the total amount of the samples is 12g, uniformly mixing 12g of the samples, placing the mixture in an argon smelting furnace, and mechanically pumping to reduce the vacuum to 1 multiplied by 10-1After Pa, the mechanical pump is turned off, the molecular pump is started to pump high vacuum to 2.3X 10-3Then, the molecular pump is closed, high-purity argon protective gas is introduced, the smelting time of the raw materials is 160s, and the raw materials are smelted for 5-6 times in a forward-reverse co-smelting mode, so that the internal components of the alloy are fully and uniformly mixed, and Al is obtained80Co13.3Mn6.7And (3) alloy ingots.
Step 2, after fully cooling, taking out the alloy ingot and cutting the alloy ingot into fragments, taking 3g of the alloy ingot, ultrasonically cleaning and drying the alloy ingot by absolute ethyl alcohol, placing the alloy ingot into a clean quartz tube, installing the quartz tube into a ribbon throwing machine, and vacuumizing the quartz tube to 7.8 multiplied by 10-3After Pa, closing vacuum, regulating the rotation speed of the copper roller to 3500 rpm, controlling the pressure difference between the quartz tube and the furnace body to be 0.1Pa, spraying the molten liquid alloy onto the copper roller rotating at high speed, rapidly cooling the liquid alloy to form an amorphous strip instantly, and preparing Al80Co13.3Mn6.7Alloy strip of Al80Co13.3Mn6.7Cutting the alloy strip into 2-3cm short strips with 1-2cm width, placing in a beaker of anhydrous ethanol, ultrasonically treating for 15min, cleaning with anhydrous ethanol, and drying in a vacuum drying oven at room temperature for over 12 h.
Step 3, drying the Al80Co13.3Mn6.7Taking out the alloy strip, placing the alloy strip in a beaker, adding 1M NaOH solution into the beaker, reacting for 48h at room temperature until no gas is generated, taking out a sample, respectively washing the sample five times by using deionized water and absolute ethyl alcohol, drying the sample for more than 12h by using a vacuum drying oven, mixing the dried alloy strip and the 1M NaOH solution, placing the mixture in a closed container, placing the closed container in a constant-temperature drying oven at 60 ℃ for 24h until no gas is generated, taking out the sample, washing the sample for 5 times by using deionized water, washing the sample for 5 times by using absolute ethyl alcohol, continuously vacuum drying the sample for 12h at room temperature by using the vacuum drying oven, taking out the dried sample, placing the sample in an alumina crucible, placing the sample in a tubular furnace, heating the sample to 60 ℃ at 5 ℃/minKeeping the temperature at 0 ℃ and 600 ℃ for 3h, and then cooling to room temperature of 20-25 ℃ along with furnace cooling to obtain the cobalt manganese oxide catalyst.
The nitrogen reduction performance of the cobalt manganese oxide catalyst is detected, the experiment is carried out in an H-type electrolytic cell isolated by a Nafion membrane at normal temperature and normal pressure, the electrolyte is 0.1M HCl, an AgCl electrode is used as a reference electrode, and a carbon rod electrode is used as a counter electrode. The nitrogen reduction measuring potential is selected from-0.05V to 0.25V.
As shown in fig. 1, the cobalt manganese oxide catalyst is composed of a uniform ultrathin nanometer sheet structure, part of nanometer sheets form a nanometer flower-shaped structure after heat treatment, the cobalt manganese oxide catalyst with the nanometer sheet structure has a large specific surface area, more active sites are exposed, and the performance is further improved.
As shown in FIG. 2, the cobalt manganese oxide catalyst particles had uneven surfaces and consisted of particles of about 10 nm. The diffraction spots showed (111), (200), (311) whose main phases were CoO, and their interplanar spacings were measured by high resolution imaging and consisted of CoO (111) with an interplanar spacing of 0.25nm and CoO (200) with an interplanar spacing of 0.21 nm.
As shown in FIG. 3, the main phases of the cobalt manganese oxide catalyst are CoO and Mn3O4And no Al related peak exists in XRD, which shows that the dealloying treatment is reasonable and effective.
As shown in FIG. 4, the spectrum of the cobalt manganese oxide catalyst is characterized by 654cm-1There is a strong peak, which is the characteristic peak of spinel, 654cm-1The characteristic peak is due to Mn at the tetrahedral position2+-O vibration, 535cm-1The characteristic peak of (c) corresponds to CoO.
Nitrogen reduction and ammonia production test are carried out on the cobalt manganese oxide catalyst obtained by the experiment, the test experiment device is shown in figure 7, the experiment is carried out at normal temperature and normal pressure and is carried out in an H-type electrolytic cell separated by a proton exchange membrane (such as a Nafion membrane), the electrolyte is 0.1M HCl, an AgCl electrode is a reference electrode, a carbon rod electrode is a counter electrode, a working electrode is an electrode made of the cobalt manganese oxide catalyst, nitrogen is continuously introduced into a cathode during the test period, and the catholyte is kept to be saturated N2And (3) solution.
As shown in figure 5, nitrogen reduction tests are respectively carried out at potentials of-0.05V to-0.25V, the catholyte is extracted to carry out indigo coloring reaction, after standing for 2 hours at room temperature, the absorbance of the catholyte at the potentials of-0.05V to-0.25V after the indigo coloring reaction is tested through ultraviolet visible absorption spectroscopy, the absorbance is different, the absorbance of nitrogen reduction at the potential of-0.15V is the highest, and the absorbance at the other potentials is not large, which indicates that the nitrogen reduction performance at the potential of-0.15V is the best.
As shown in FIG. 6, the ammonia yield of-0.05V to-0.25V under different potentials and the highest ammonia yield of-0.15V can reach 5.3ug/h mgcatThe difference is not large under the other potentials and is 2-3ug/h mgcat. The cobalt manganese oxide catalyst can solve the problem of low ammonia yield of the nitrogen reduction catalyst, so the cobalt manganese oxide catalyst has good commercial prospect.
Example 2
Step 1, mixing 80 atomic percent of pure aluminum, 10 atomic percent of pure cobalt and 10 atomic percent of pure manganese, placing the materials in an argon smelting furnace, and mechanically pumping to obtain a low vacuum of 1 multiplied by 10-1After Pa, the mechanical pump is closed, the molecular pump is started to pump high vacuum to 2.0X 10-3Then, the molecular pump is closed, high-purity nitrogen protective gas is introduced, the smelting time of the raw materials is 240s, and the raw materials are smelted for 5-6 times in a forward-reverse co-smelting mode, so that the internal components of the alloy are fully and uniformly mixed, and Al is obtained80Co10Mn10And (3) alloy ingots.
Step 2, after fully cooling, taking out the alloy ingot and cutting the alloy ingot into fragments, taking 3g of the alloy ingot, ultrasonically cleaning and drying the alloy ingot by absolute ethyl alcohol, placing the alloy ingot into a clean quartz tube, installing the quartz tube into a ribbon throwing machine, and vacuumizing the quartz tube to 1 x 10-2After Pa, closing vacuum, regulating the rotation speed of the copper roller to 2500 rpm, controlling the pressure difference between the quartz tube and the furnace body to be 0.1Pa, spraying the molten liquid alloy onto the copper roller rotating at high speed, rapidly cooling the liquid alloy to form an amorphous strip instantly, and preparing Al80Co10Mn10Alloy strip of Al80Co10Mn10Cutting the alloy strip into 2-3cm short strip with width of 1-2cm, and placing in anhydrous alcohol beaker with ultrasonic 15min, then washing with absolute ethyl alcohol, and drying in a vacuum drying oven at room temperature for more than 12 h.
Step 3, drying the Al80Co10Mn10Taking out the alloy strips, placing the alloy strips in a beaker, adding 0.5M NaOH solution into the beaker, reacting for 48 hours at room temperature until no gas is generated, taking out a sample, respectively washing the sample with deionized water and absolute ethyl alcohol for five times, drying the sample for more than 12 hours in a vacuum drying oven, mixing the dried alloy strips with 1M NaOH solution, placing the mixture in a closed container, placing the closed container in a constant-temperature drying oven at 25 ℃, reacting for 48 hours, until no gas is generated, taking out the sample, washing with deionized water for 5 times, washing with anhydrous ethanol for 5 times, then continuing to vacuum-dry with a vacuum drying oven at room temperature for 12 hours, taking out the dried sample, placing the sample in an alumina crucible, placing the alumina crucible in a tubular furnace, heating the sample to 280 ℃ at a speed of 4 ℃/min, preserving the heat of the sample for 5 hours at 280 ℃, and then cooling the sample to the room temperature of 20-25 ℃ along with furnace cooling to obtain the cobalt-manganese oxide catalyst.
Example 3
Step 1, proportioning 70 percent of pure aluminum, 15 percent of pure cobalt and 15 percent of pure manganese by atom percent, placing the mixture in an argon smelting furnace, and mechanically pumping to a low vacuum of 1 multiplied by 10-1After Pa, the mechanical pump is closed, the molecular pump is started to pump high vacuum to 3.0X 10-3Then, the molecular pump is closed, high-purity helium protective gas is introduced, the smelting time of the raw materials is 120s, and the raw materials are smelted for 5-6 times in a forward-reverse co-smelting mode, so that the internal components of the alloy are fully and uniformly mixed, and Al is obtained70Co15Mn15And (3) alloy ingots.
Step 2, after fully cooling, taking out the alloy ingot and cutting the alloy ingot into fragments, taking 3g of the alloy ingot, ultrasonically cleaning and drying the alloy ingot by absolute ethyl alcohol, placing the alloy ingot into a clean quartz tube, installing the quartz tube into a ribbon throwing machine, and vacuumizing the quartz tube to 1 x 10-2After Pa, closing vacuum, regulating the rotation speed of the copper roller to 4000 revolutions per minute, controlling the pressure difference between the quartz tube and the inside of the furnace body to be 0.4Pa, spraying the molten liquid alloy on the copper roller rotating at high speed, rapidly cooling the liquid alloy to form an amorphous strip instantly, and preparing Al70Co15Mn15Alloy strip of Al70Co15Mn15Cutting the alloy strip into 2-3cm short strips with 1-2cm width, placing in a beaker of anhydrous ethanol, ultrasonically treating for 15min, cleaning with anhydrous ethanol, and drying in a vacuum drying oven at room temperature for over 12 h.
Step 3, drying the Al70Co15Mn15Taking out the alloy strip, placing the alloy strip in a beaker, adding 5M NaOH solution into the beaker, reacting for 12h at room temperature until no gas is generated, taking out a sample, respectively washing the sample with deionized water and absolute ethyl alcohol for five times, drying for more than 12h by using a vacuum drying oven, mixing the dried alloy strip with 2M NaOH solution, placing the mixture in a closed container, placing the container in a constant-temperature drying oven at 60 ℃, reacting for 12h, until no gas is generated, taking out the sample, washing with deionized water for 5 times, washing with anhydrous ethanol for 5 times, then continuing to vacuum-dry with a vacuum drying oven at room temperature for 12 hours, taking out the dried sample, placing the sample in an alumina crucible, placing the alumina crucible in a tubular furnace, heating the sample to 650 ℃ at the speed of 8 ℃/min, preserving the heat of the sample for 1h at 650 ℃, and then cooling the sample to the room temperature of 20-25 ℃ along with furnace cooling to obtain the cobalt-manganese oxide catalyst.
Example 4
Step 1, proportioning 75 atomic percent of pure aluminum, 10 atomic percent of pure cobalt and 15 atomic percent of pure manganese, placing the mixture in an argon smelting furnace, and mechanically pumping to obtain a low vacuum of 1 multiplied by 10-1After Pa, the mechanical pump is closed, the molecular pump is started to pump high vacuum to 2.0-3.0X 10-3Then, the molecular pump is closed, high-purity argon protective gas is introduced, and forward-reverse smelting is carried out for 5-6 times in 200s, so that the internal components of the alloy are fully and uniformly mixed, and Al is obtained75Co10Mn15And (3) alloy ingot.
Step 2, after fully cooling, taking out the alloy ingot and cutting the alloy ingot into fragments, taking 3g of the alloy ingot, ultrasonically cleaning and drying the alloy ingot by absolute ethyl alcohol, placing the alloy ingot into a clean quartz tube, installing the quartz tube into a ribbon throwing machine, and vacuumizing the quartz tube to 1 x 10-2After Pa, the vacuum is closed, the rotation speed of the copper roller is adjusted to 3000 r/min, the pressure difference between the quartz tube and the furnace body is controlled to be 0.2Pa, and the melted liquid alloy is sprayed on the copper roller rotating at high speed to ensure that the liquid is moltenRapidly cooling the alloy to form amorphous strips at the moment to prepare Al75Co10Mn15Alloy strip of Al75Co10Mn15Cutting the alloy strip into 2-3cm short strips with 1-2cm width, placing in a beaker of anhydrous ethanol, ultrasonically treating for 15min, cleaning with anhydrous ethanol, and drying in a vacuum drying oven at room temperature for over 12 h.
Step 3, drying the Al75Co10Mn15Taking out the alloy strips, placing the alloy strips in a beaker, adding 2.5M NaOH solution into the beaker, reacting for 24h at room temperature until no gas is generated, taking out a sample, respectively washing the sample with deionized water and absolute ethyl alcohol for five times, drying the sample for more than 12h with a vacuum drying oven, mixing the dried alloy strips with 1.5M NaOH solution, placing the mixture in a closed container, placing the container in a constant-temperature drying oven at 40 ℃, reacting for 36 h, until no gas is generated, taking out the sample, washing with deionized water for 5 times, washing with anhydrous ethanol for 5 times, then continuing to vacuum-dry with a vacuum drying oven at room temperature for 12 hours, taking out the dried sample, placing the sample in an alumina crucible, placing the alumina crucible in a tubular furnace, heating the sample to 300 ℃ at the speed of 9 ℃/min, preserving the heat for 2h at the temperature of 300 ℃, and then cooling the sample to the room temperature of 20-25 ℃ along with furnace cooling to obtain the cobalt-manganese oxide catalyst.
The invention has been described in an illustrative manner, and it is to be understood that any simple variations, modifications or other equivalent changes which can be made by one skilled in the art without departing from the spirit of the invention fall within the scope of the invention.

Claims (4)

1. The application of the high-efficiency nitrogen reduction cobalt manganese oxide catalyst in the field of nitrogen reduction catalysis is characterized in that: the cobalt manganese oxide catalyst has the best nitrogen reduction performance under-0.15V, and the highest ammonia yield under-0.15V, which can reach 5.3ug/h mgcatThe high-efficiency nitrogen reduction cobalt manganese oxide catalyst is prepared by the following steps:
step 1, preparing Al-Co-Mn alloy strip
According to the method, high-purity metal raw materials are selected for proportioning according to the atom percentage of pure aluminum of 80 percent, the atom percentage of pure cobalt of 13 to 14 percent and the atom percentage of pure manganese of 6 to 7 percent, wherein the purity of the metal raw materials is higher than 99.9 percent, namely the purity of an aluminum simple substance, a cobalt simple substance and a manganese simple substance is more than or equal to 99.9 percent, the active and easily-oxidized metal raw materials need to be polished by sand paper to remove oxide films on the surfaces, then the mixture is cleaned and then proportioned, the mixture is smelted by adopting a smelting furnace in the atmosphere of inert protective gas, the smelting time of the raw materials is 120 times plus 240s, the mixture is repeatedly smelted into Al-Co-Mn alloy ingots with uniform components, then surface scale skins of the Al-Co-Mn alloy ingots are removed, the Al-Co-Mn alloy ingots are placed in a quartz tube with small holes at the bottom end, a strip throwing machine is pumped to vacuum and then filled with the inert protective gas, heating the alloy by eddy current generated by an inductance coil to melt the alloy, pressing a jetting key after the alloy is completely melted, jetting alloy liquid from a quartz tube nozzle on a copper roller rotating at high speed under the action of pressure difference above and at the bottom of a quartz tube to obtain an alloy strip, cutting the alloy strip into a section with the length of 2-3cm and the width of 1-2cm, putting the section into a beaker, ultrasonically cleaning the section by absolute ethyl alcohol, and drying the section in a vacuum drying box at 20-25 ℃ to obtain an Al-Co-Mn alloy strip;
step 2, preparing cobalt manganese oxide catalyst
Placing the Al-Co-Mn alloy strip prepared in the step 1 in NaOH solution to remove Al in the Al-Co-Mn alloy strip, then placing the Al-Co-Mn alloy strip in a tube furnace, heating to 280 ℃ and 650 ℃ at a heating rate of 3-9 ℃/min, preserving heat for 1-5h, and naturally cooling to room temperature of 20-25 ℃ to obtain the cobalt-manganese oxide catalyst, wherein the main phases of the cobalt-manganese oxide catalyst are CoO and Mn3O4。
2. The application of the high-efficiency nitrogen-reduced cobalt manganese oxide catalyst in the field of nitrogen reduction catalysis, which is disclosed by claim 1, is characterized in that: in step 1, after smelting, overturning each alloy ingot by using a material turning spoon for remelting, wherein the smelting frequency of each alloy ingot is not less than five times, inert protective gas is nitrogen, helium or argon, and before smelting, the vacuum degree is pumped to 1 × 10-1Pa or less, meltingThe vacuum degree of (A) is 2.0-3.0X 10-3Pa below, the smelting time is 160-200 s.
3. The application of the high-efficiency nitrogen-reduced cobalt manganese oxide catalyst in the field of nitrogen reduction catalysis, which is disclosed by claim 1, is characterized in that: in step 1, the conditions for preparing the Al-Co-Mn alloy strip are as follows: vacuum degree of 1X 10-2Pa below, the rotation speed of the copper roller is 2500-.
4. The application of the high-efficiency nitrogen-reduced cobalt manganese oxide catalyst in the field of nitrogen reduction catalysis, which is disclosed by claim 1, is characterized in that: in the step 2, the Al-Co-Mn alloy strip is placed in 0.5-5M NaOH solution at the room temperature of 20-25 ℃ for reaction for 12-48h until no gas is generated, the Al-Co-Mn alloy strip is cleaned and dried, then the Al-Co-Mn alloy strip and the 1-2M NaOH solution are mixed and placed in a closed container again, the mixture is reacted for 12-48h in a constant-temperature drying box at the temperature of 25-60 ℃ until no gas is generated, the temperature rise rate of the tubular furnace is 4-8 ℃/min, the heat preservation temperature is 600 ℃, and the heat preservation time is 1-3 h.
CN201910600630.5A 2019-07-04 2019-07-04 High-efficiency nitrogen reduction cobalt manganese oxide catalyst and preparation method thereof Active CN110368951B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201910600630.5A CN110368951B (en) 2019-07-04 2019-07-04 High-efficiency nitrogen reduction cobalt manganese oxide catalyst and preparation method thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201910600630.5A CN110368951B (en) 2019-07-04 2019-07-04 High-efficiency nitrogen reduction cobalt manganese oxide catalyst and preparation method thereof

Publications (2)

Publication Number Publication Date
CN110368951A CN110368951A (en) 2019-10-25
CN110368951B true CN110368951B (en) 2022-05-17

Family

ID=68252033

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201910600630.5A Active CN110368951B (en) 2019-07-04 2019-07-04 High-efficiency nitrogen reduction cobalt manganese oxide catalyst and preparation method thereof

Country Status (1)

Country Link
CN (1) CN110368951B (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111939924B (en) * 2020-08-21 2023-05-09 赣州有色冶金研究所有限公司 Composite catalyst for ozone oxidation and preparation method thereof

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1616702A (en) * 2003-11-14 2005-05-18 兰州理工大学 Aluminium base noncrystal alloy and its preparing method
CN107999114A (en) * 2017-12-19 2018-05-08 成都玖奇新材料科技有限公司 Electrochemical reduction nitrogen ammonia non-precious metal catalyst
CN108339550A (en) * 2017-01-24 2018-07-31 天津大学 Cellular cobalt-manganese spinel microballoon and its preparation method and application

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6712950B2 (en) * 2002-03-04 2004-03-30 Lynntech, Inc. Electrochemical synthesis of ammonia

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1616702A (en) * 2003-11-14 2005-05-18 兰州理工大学 Aluminium base noncrystal alloy and its preparing method
CN108339550A (en) * 2017-01-24 2018-07-31 天津大学 Cellular cobalt-manganese spinel microballoon and its preparation method and application
CN107999114A (en) * 2017-12-19 2018-05-08 成都玖奇新材料科技有限公司 Electrochemical reduction nitrogen ammonia non-precious metal catalyst

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
"复合金属氧化物的制备及其锂电性能的研究";赵殿云;《万方数据知识服务平台》;20170414;第四章第4.2.1节、图4.1a和b、f、图4.4 *

Also Published As

Publication number Publication date
CN110368951A (en) 2019-10-25

Similar Documents

Publication Publication Date Title
Han et al. Hollow titanium dioxide spheres as anode material for lithium ion battery with largely improved rate stability and cycle performance by suppressing the formation of solid electrolyte interface layer
Wang et al. Pt nanoparticle and CdS quantum dot assisted WO 3 nanowires grown on flexible carbon fibers for efficient oxygen production
Ke et al. Enhanced electrocatalytic activity on gold nanocrystals enclosed by high-index facets for oxygen reduction
EP1967492B1 (en) Method for producing purified carbon nanotubes
CN106981671A (en) A kind of three-dimensional porous nitrogen-doped graphene and its preparation method and application
Li et al. Lead citrate precursor route to synthesize nanostructural lead oxide from spent lead acid battery paste
CN109023161A (en) A kind of Fe-Ni-P-C system amorphous alloy elctro-catalyst and its preparation method and application
CN108914156B (en) Fe-Co-Mo-P-C amorphous alloy electrocatalyst and preparation method and application thereof
CN110368951B (en) High-efficiency nitrogen reduction cobalt manganese oxide catalyst and preparation method thereof
CN115852390A (en) FeCoNiBPt high-entropy amorphous alloy electrolytic water catalytic material and preparation method thereof
Zhao et al. A comparative investigation of electrocatalysis at Pt monolayers on shape-controlled Au nanocrystals: facet effect versus strain effect
Duraisamy et al. Hard template derived N, S dual heteroatom doped ordered mesoporous carbon as an efficient electrocatalyst for oxygen reduction reaction
CN106315691A (en) Nanometer Co 3O4 with cobalt defects and preparation method thereof, and application thereof in oxygen production through electro-catalysis water decomposition
Hu et al. Microwave shock process for rapid synthesis of 2D porous La0. 2Sr0. 8CoO3 perovskite as an efficient oxygen evolution reaction catalyst
CN111068647A (en) Nano TiO (titanium dioxide)2-SnO2Preparation method of solid solution photocatalytic material
Lei et al. Preparation of ZrMn2 hydrogen storage alloy by electro-deoxidation in molten calcium chloride
CN108767268A (en) A kind of preparation method and application of Cu nano bar-shapes structure catalyst
JP6716219B2 (en) Method for producing Ti4O7
Ru et al. Dissolution-electrodeposition pathway and bulk porosity on the impact of in situ reduction of solid PbO in deep eutectic solvent
CN110358985A (en) A method of improving Fe-Co-P-C system amorphous alloy electrocatalysis characteristic
CN110706939A (en) Nano porous nickel alloy/manganese dioxide electrode material and preparation method and application thereof
CN105478119A (en) Anode catalyst material for direct alcohol fuel cell and preparation method for anode catalyst material
CN105152146A (en) Preparation method of TiN nano-material
CN110433832B (en) Self-supporting nano porous nitrogen reduction catalyst and preparation method thereof
CN109746000A (en) A kind of preparation and application of carbon coating vanadic sulfide elctro-catalyst

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant