CN111545191B - Lithium potassium manganese composite oxide catalyst capable of being regenerated in heating mode and used for ozonolysis and preparation method thereof - Google Patents

Lithium potassium manganese composite oxide catalyst capable of being regenerated in heating mode and used for ozonolysis and preparation method thereof Download PDF

Info

Publication number
CN111545191B
CN111545191B CN202010316417.4A CN202010316417A CN111545191B CN 111545191 B CN111545191 B CN 111545191B CN 202010316417 A CN202010316417 A CN 202010316417A CN 111545191 B CN111545191 B CN 111545191B
Authority
CN
China
Prior art keywords
manganese
lithium
potassium
temperature
preparing
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
CN202010316417.4A
Other languages
Chinese (zh)
Other versions
CN111545191A (en
Inventor
朱天乐
洪威
刘严
孙也
王海宁
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.)
Beihang University
Original Assignee
Beihang 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 Beihang University filed Critical Beihang University
Priority to CN202010316417.4A priority Critical patent/CN111545191B/en
Publication of CN111545191A publication Critical patent/CN111545191A/en
Application granted granted Critical
Publication of CN111545191B publication Critical patent/CN111545191B/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
    • B01J23/16—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of arsenic, antimony, bismuth, vanadium, niobium, tantalum, polonium, chromium, molybdenum, tungsten, manganese, technetium or rhenium
    • B01J23/32—Manganese, technetium or rhenium
    • B01J23/34—Manganese
    • 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
    • B01D53/34—Chemical or biological purification of waste gases
    • B01D53/74—General processes for purification of waste gases; Apparatus or devices specially adapted therefor
    • B01D53/86—Catalytic processes
    • B01D53/8671—Removing components of defined structure not provided for in B01D53/8603 - B01D53/8668
    • B01D53/8675—Ozone
    • 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
    • B01J23/90—Regeneration or reactivation
    • B01J23/92—Regeneration or reactivation of catalysts comprising metals, oxides or hydroxides provided for in groups B01J23/02 - B01J23/36
    • 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
    • B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
    • B01J37/08—Heat treatment
    • B01J37/082—Decomposition and pyrolysis
    • B01J37/088—Decomposition of a metal salt
    • 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
    • B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
    • B01J37/08—Heat treatment
    • B01J37/10—Heat treatment in the presence of water, e.g. steam
    • 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
    • B01J38/00—Regeneration or reactivation of catalysts, in general
    • B01J38/02—Heat treatment
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2258/00—Sources of waste gases
    • B01D2258/06—Polluted air
    • 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
    • B01J2523/00—Constitutive chemical elements of heterogeneous catalysts
    • 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
    • Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
    • Y02A50/00—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE in human health protection, e.g. against extreme weather
    • Y02A50/20—Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Materials Engineering (AREA)
  • Organic Chemistry (AREA)
  • Thermal Sciences (AREA)
  • Physics & Mathematics (AREA)
  • Environmental & Geological Engineering (AREA)
  • Biomedical Technology (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • General Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Health & Medical Sciences (AREA)
  • Battery Electrode And Active Subsutance (AREA)
  • Catalysts (AREA)

Abstract

The invention discloses a lithium potassium manganese composite oxide catalyst for ozonolysis capable of being regenerated by heating and a preparation method thereof. Wherein, manganese oxide is the main active component of the catalyst, and lithium oxide and potassium oxide are the promoter components. The component of the lithium potassium manganese composite oxide catalyst is LiaKbMn8O16The atomic percentage content of a is 0.1-5, and the atomic percentage content of b is 0.1-5.

Description

Lithium potassium manganese composite oxide catalyst capable of being regenerated in heating mode and used for ozonolysis and preparation method thereof
Technical Field
The invention relates to an ozone catalyst, in particular to a lithium potassium manganese composite oxide catalyst for ozone decomposition capable of being regenerated by heating and a preparation method thereof.
Background
In recent years, ozone is becoming one of the main pollutants of urban environmental air, especially indoor air, in China. Indoor air ozone mainly comes from two aspects: firstly, ozone generated by atmospheric photochemical reaction enters the room along with the exchange of indoor and outdoor air; and secondly, ozone can be released in the use processes of modern office equipment and household appliances involving high pressure or laser, air purifiers, ultraviolet lamps, negative ion generators and the like. Studies have shown that prolonged exposure to high concentrations of ozone can cause respiratory disease, exacerbate asthma, and even lead to cardiopulmonary failure. Therefore, reducing indoor ozone pollution is of interest to environmental science researchers.
The current methods for treating ozone mainly comprise: atmospheric dilution, activated carbon adsorption, chemical absorption, thermal decomposition, catalytic decomposition, and the like. The atmospheric dilution method mainly reduces the concentration of ozone by enhancing the air exchange between the indoor air and the outdoor air, but aggravates the pollution condition of the indoor air environment if the outdoor air is polluted; the activated carbon adsorption method is to utilize the strong adsorption characteristic to adsorb and degrade ozone, but has the problems of low efficiency and even failure in the later adsorption period, frequent replacement, difficult recovery, easy secondary environmental pollution and the like, and has explosion danger if improper treatment is carried out in the use process; the liquid medicine absorption method and the thermal decomposition method respectively have the problems of difficult treatment of waste liquid, large energy consumption in use and the like; the catalytic decomposition method is an effective way for treating indoor ozone pollution due to the characteristics of safety, economy, high efficiency and the like. Among them, catalytic degradation techniques using oxides containing manganese as a representative catalyst have been widely paid attention to and studied in the removal of ozone from air. However, the existing catalyst for treating ozone still has the problems of poor controllability of preparation conditions, high cost of raw materials, poor humidity resistance, low ozone decomposition rate, easy inactivation and the like.
Disclosure of Invention
The invention provides a lithium potassium manganese composite oxide catalyst for ozonolysis capable of being regenerated by heating and a preparation method thereof, aiming at the technical problems of high preparation cost, difficult high-temperature regeneration and the like of the existing ozone catalyst; the ozone catalyst prepared by the method has the characteristics of low cost of raw materials, strong controllability of operation conditions, good ozone decomposition effect of the catalyst under the condition of room temperature and high humidity, repeated heating regeneration, good use performance and the like.
In order to realize the purpose of efficiently decomposing ozone in air under the condition of room temperature and high humidity, the invention takes an ammonium source, a manganese source, a lithium source and a potassium source as main raw materials and adopts a hydrothermal method, a selective dissolution method and a solid-phase mixing reaction method to prepare the lithium-potassium-manganese composite oxide catalyst. Wherein, manganese oxide is the main active component of the catalyst, and lithium oxide and potassium oxide are the promoter components.
The invention relates to a lithium potassium manganese composite oxide catalyst for ozonolysis, which can be regenerated by heating and comprises the following components of LiaKbMn8O16Wherein the atomic percentage content of a is 0.1-5, and the atomic percentage content of b is 0.1-5.
The invention relates to a preparation method of a lithium potassium manganese composite oxide catalyst for ozonolysis, which comprises the following steps:
step one, preparing manganese oxide powder by a hydrothermal reaction method;
step 11, batching;
weighing an ammonium source and a manganese source according to a certain molar ratio of ammonium to manganese;
the molar ratio of ammonium to manganese of the ammonium source and the manganese source is 1: 1-10: 1;
the ammonium source is any one of ammonium persulfate, ammonium sulfate, ammonium chloride, ammonium acetate and ammonium nitrate or a mixture of at least two of the ammonium sources in any mass ratio;
the manganese source is any one of manganese sulfate, manganese nitrate, manganese carbonate and manganese chloride or a mixture of at least two of manganese sulfate, manganese nitrate, manganese carbonate and manganese chloride in any mass ratio;
step 12, preparing manganese oxide powder;
adding the ammonium source and the manganese source weighed in the step 11 into deionized water, fully and uniformly mixing, adjusting the pH of the mixed solution by using dilute hydrochloric acid, then transferring into a high-pressure hydrothermal reaction kettle, and placing into a high-temperature constant-temperature furnace for hydrothermal reaction to obtain manganese oxide powder;
reaction parameters are as follows: adjusting the pH of the mixed solution to be less than 1;
the hydrothermal temperature is 80-150 ℃;
the hydrothermal time is 4-20 h;
the manganese oxide powder prepared by the step one is alpha-MnO2、β-MnO2And gamma-MnO2A mixed crystal structure in which three crystal structures coexist;
step two: preparing lithium manganese solid powder by a high-temperature solid-phase reaction method;
step 21, batching;
weighing a lithium source and the manganese oxide powder prepared in the first step according to a certain mass ratio;
the mass ratio of the lithium source to the manganese oxide is 0.1: 1-5: 1;
the lithium source is one or a mixture of at least two of lithium sulfate, lithium nitrate, lithium chloride, lithium carbonate and lithium hydroxide in any mass ratio;
step 22, preparing lithium manganese solid powder;
fully and uniformly mixing the lithium source and the manganese oxide weighed in the step 21, and placing the mixture in a muffle furnace for high-temperature roasting to obtain lithium-manganese solid powder;
roasting parameters are as follows: the roasting atmosphere is air;
the roasting temperature is 400-600 ℃;
the roasting time is 2-48 h;
the lithium manganese solid powder prepared by the step two is Li2MnO3A crystal structure;
step three: preparing a lithium manganese oxide precursor by a selective dissolution method;
step 31, batching;
preparing an acid solution with a certain pH value, and weighing the acid solution and the lithium manganese solid powder prepared in the second step according to a certain mass ratio;
the pH value of the acid solution is 1-3;
the acid solution is one of dilute sulfuric acid, dilute hydrochloric acid and dilute nitric acid or a mixture of at least two of the dilute sulfuric acid, the dilute hydrochloric acid and the dilute nitric acid in any mass ratio;
the mass ratio of the acid solution to the lithium manganese solid powder is 30: 1-150: 1;
step 32, preparing a lithium manganese oxide precursor;
fully mixing the acid solution weighed in the step 31 with the lithium manganese solid powder, continuously stirring, and carrying out selective dissolution reaction to obtain a lithium manganese oxide precursor;
reaction parameters are as follows: the stirring speed is 300-1500 r/s;
the reaction temperature is 20-90 ℃;
the reaction time is 2-48 h;
the precursor powder of the lithium manganese oxide prepared by the step three is epsilon-MnO2A crystal structure;
step four: preparing a lithium potassium manganese composite oxide catalyst by a high-temperature solid-phase reaction method;
step 41, batching;
weighing a potassium source and the lithium manganese oxide precursor prepared in the third step according to a certain mass ratio;
the potassium source is any one of potassium nitrate, potassium carbonate, potassium sulfate or potassium chloride or a mixture of at least two of potassium nitrate, potassium carbonate, potassium sulfate and potassium chloride in any mass ratio;
the mass ratio of the potassium source to the lithium manganese oxide is 0.1: 1-1: 1
Step 42, preparation of lithium potassium manganese oxide catalyst
Fully and uniformly mixing the potassium source weighed in the step 41 with the lithium manganese oxide precursor, and placing the mixture in a muffle furnace for high-temperature roasting to obtain LiaKbMn8O16A lithium potassium manganese composite oxide catalyst;
roasting parameters are as follows: the roasting atmosphere is air;
the roasting temperature is 350-750 ℃;
the roasting time is 2-48 h;
li prepared by the fourth stepaKbMn8O16The catalyst being alpha-MnO2A crystal structure.
Compared with the prior art, the invention has the following advantages:
the preparation process of the lithium potassium manganese composite oxide catalyst is simple and environment-friendly, the used raw materials are wide in source and are all commercialized, the cost is low, the utilization rate of the raw materials in the preparation process is high, and the preparation method is suitable for large-scale production.
The lithium potassium manganese composite oxide catalyst prepared by the invention has an alpha-phase manganese dioxide crystal structure, and has better ozone catalytic decomposition activity, stronger moisture resistance and longer service life compared with the traditional manganese oxide material due to the contained lithium, potassium and other auxiliary catalytic components.
The lithium potassium manganese composite oxide catalyst has high thermal stability, the structure of the catalyst is not changed after the catalyst is heated and regenerated at 500 ℃, the catalyst can be efficiently regenerated, and the catalyst is favorable for recycling for many times.
Drawings
FIG. 1 is an X-ray diffraction pattern of the manganese oxide powder prepared in step one of inventive example 1.
FIG. 2 is an X-ray diffraction pattern of the solid lithium manganese powder prepared in step two of inventive example 1.
Fig. 3 is an X-ray diffraction pattern of a lithium manganese oxide precursor prepared in step three of example 1 of the present invention.
FIG. 4 is Li prepared in example 1 of the present invention0.8K2.5Mn8O16X-ray diffraction pattern of the catalyst powder.
FIG. 5 is an X-ray diffraction pattern of the composition of comparative example 1 of the present invention.
FIG. 6 is an X-ray diffraction pattern of the composition of comparative example 2 of the present invention.
FIG. 7 is an X-ray diffraction pattern of the composition of comparative example 3 of the present invention.
Detailed Description
The present invention will be described in further detail with reference to the accompanying drawings and examples.
Example 1
Preparation of Li0.8K2.5Mn8O16The method of the catalyst comprises the following steps:
step one, preparing manganese oxide powder by a hydrothermal reaction method;
step 11, batching;
weighing ammonium persulfate and manganese sulfate according to the molar ratio of ammonium to manganese of 1: 1;
step 12, preparing manganese oxide powder;
adding the ammonium persulfate and the manganese sulfate weighed in the step 11 into deionized water, fully and uniformly mixing, adjusting the pH of the mixed solution by using dilute hydrochloric acid, then transferring into a high-pressure hydrothermal reaction kettle, and placing into a high-temperature constant-temperature furnace for hydrothermal reaction to obtain manganese oxide powder;
reaction parameters are as follows: adjusting the pH of the mixed solution to be less than 1;
the hydrothermal temperature is 80 ℃;
the hydrothermal time is 4 h;
for manganese oxide prepared in the first step of example 1The compound powder was subjected to structural analysis using an X-ray diffractometer model Rigaku D/MAX-2200 of Japan, as shown in FIG. 1, and the manganese oxide powder was α -MnO2、β-MnO2And gamma-MnO2The three crystal structures coexist to form a mixed crystal structure.
Step two: preparing lithium manganese solid powder by a high-temperature solid-phase reaction method;
step 21, batching;
weighing lithium nitrate and the manganese oxide powder prepared in the first step according to the mass ratio of 1: 1;
step 22, preparing lithium manganese solid powder;
fully and uniformly mixing the lithium nitrate and the manganese oxide weighed in the step 21, and placing the mixture in a muffle furnace for high-temperature roasting to obtain lithium-manganese solid powder;
roasting parameters are as follows: the roasting atmosphere is air;
the roasting temperature is 400 ℃;
the roasting time is 2 hours;
the solid lithium manganese powder obtained in the second step of example 1 was subjected to structural analysis using an X-ray diffractometer, model Rigaku D/MAX-2200, Japan, as shown in FIG. 2, and was Li2MnO3A crystal structure.
Step three: preparing a lithium manganese oxide precursor by a selective dissolution method;
step 31, batching;
preparing a dilute hydrochloric acid solution with the pH of 2, and weighing the acid solution and the lithium manganese solid powder prepared in the second step according to the mass ratio of 30: 1;
step 32, preparing a lithium manganese oxide precursor;
fully mixing the diluted hydrochloric acid solution weighed in the step 31 with the lithium manganese solid powder, continuously stirring, and carrying out selective dissolution reaction to obtain a lithium manganese oxide precursor;
reaction parameters are as follows: the stirring speed is 300 r/s;
the reaction temperature is 20 ℃;
the reaction time is 2 h;
for the lithium manganese oxide precursor prepared in step three of example 1The structure of the sample was analyzed by using a Nippon Rigaku model D/MAX-2200X-ray diffractometer, as shown in FIG. 3, and the powder of the product obtained in the third step was ε -MnO2A crystal structure.
Step four: preparing a lithium potassium manganese composite oxide catalyst by a high-temperature solid-phase reaction method;
step 41, batching;
weighing potassium nitrate and the lithium manganese oxide precursor prepared in the third step according to the mass ratio of 0.5: 1;
step 42, preparation of lithium potassium manganese oxide catalyst
Fully and uniformly mixing the potassium nitrate weighed in the step 41 with the lithium manganese oxide precursor, and placing the mixture in a muffle furnace for high-temperature roasting to obtain Li0.8K2.5Mn8O16A catalyst;
roasting parameters are as follows: the roasting atmosphere is air;
the roasting temperature is 550 ℃;
the roasting time is 2 h.
For Li prepared in step four of example 10.8K2.5Mn8O16The catalyst was subjected to structural analysis using a Nippon Rigaku model D/MAX-2200X-ray diffractometer, as shown in FIG. 4, and the product powder obtained in the fourth step was α -MnO2A crystal structure.
Example 2
Preparation of Li1.5K5.0Mn8O16The method of the catalyst comprises the following steps:
step one, preparing manganese oxide powder by a hydrothermal reaction method;
step 11, batching;
weighing ammonium sulfate and manganese nitrate according to the molar ratio of ammonium to manganese of 10: 1;
step 12, preparing manganese oxide powder;
adding the ammonium sulfate and the manganese nitrate weighed in the step 11 into deionized water, fully and uniformly mixing, adjusting the pH of the mixed solution by using dilute hydrochloric acid, then transferring the mixed solution into a high-pressure hydrothermal reaction kettle, and placing the high-pressure hydrothermal reaction kettle in a high-temperature constant-temperature furnace for hydrothermal reaction to obtain manganese oxide powder;
reaction parameters are as follows: adjusting the pH of the mixed solution to be less than 1;
the hydrothermal temperature is 150 ℃;
the hydrothermal time is 4 h;
the manganese oxide powder prepared by the step one is alpha-MnO2、β-MnO2And gamma-MnO2A mixed crystal structure in which three crystal structures coexist;
step two: preparing lithium manganese solid powder by a high-temperature solid-phase reaction method;
step 21, batching;
weighing lithium sulfate and the manganese oxide powder prepared in the first step according to the mass ratio of 5: 1;
step 22, preparing lithium manganese solid powder;
fully and uniformly mixing the lithium sulfate and the manganese oxide weighed in the step 21, and placing the mixture in a muffle furnace for high-temperature roasting to obtain lithium-manganese solid powder;
roasting parameters are as follows: the roasting atmosphere is air;
the roasting temperature is 600 ℃;
the roasting time is 48 h;
the lithium manganese solid powder prepared by the step two is Li2MnO3A crystal structure;
step three: preparing a lithium manganese oxide precursor by a selective dissolution method;
step 31, batching;
preparing a dilute nitric acid solution with the pH value of 3, and weighing the acid solution and the lithium manganese solid powder prepared in the second step according to the mass ratio of 150: 1;
step 32, preparing a lithium manganese oxide precursor;
fully mixing the diluted nitric acid solution weighed in the step 31 with the lithium manganese solid powder, continuously stirring, and carrying out selective dissolution reaction to obtain a lithium manganese oxide precursor;
reaction parameters are as follows: the stirring speed is 1500 r/s;
the reaction temperature is 90 ℃;
the reaction time is 48 h;
through step IIIThe obtained lithium manganese oxide precursor powder is epsilon-MnO2A crystal structure;
step four: preparing a lithium potassium manganese composite oxide catalyst by a high-temperature solid-phase reaction method;
step 41, batching;
weighing potassium carbonate and the lithium manganese oxide precursor prepared in the third step according to the mass ratio of 1: 1;
step 42, preparation of lithium potassium manganese oxide catalyst
Fully and uniformly mixing the potassium carbonate weighed in the step 41 with a manganese oxide precursor, and placing the mixture in a muffle furnace for high-temperature roasting to obtain Li1.5K5.0Mn8O16A catalyst;
roasting parameters are as follows: the roasting atmosphere is air;
the roasting temperature is 750 ℃;
the roasting time is 48 h;
li prepared by the fourth step1.5K5.0Mn8O16The catalyst being alpha-MnO2A crystal structure.
Example 3
Preparation of Li0.3K0.5Mn8O16The method of the catalyst comprises the following steps:
step one, preparing manganese oxide powder by a hydrothermal reaction method;
step 11, batching;
weighing ammonium chloride and manganese carbonate according to the molar ratio of ammonium to manganese of 2: 1;
step 12, preparing manganese oxide powder;
adding the ammonium chloride and the manganese carbonate weighed in the step 11 into deionized water, fully and uniformly mixing, adjusting the pH of the mixed solution by using dilute hydrochloric acid, then transferring the mixed solution into a high-pressure hydrothermal reaction kettle, and placing the high-pressure hydrothermal reaction kettle in a high-temperature constant-temperature furnace for hydrothermal reaction to obtain manganese oxide powder;
reaction parameters are as follows: adjusting the pH of the mixed solution to be less than 1;
the hydrothermal temperature is 130 ℃;
the hydrothermal time is 4 h;
the manganese oxide powder prepared by the step one is alpha-MnO2、β-MnO2And gamma-MnO2A mixed crystal structure in which three crystal structures coexist;
step two: preparing lithium manganese solid powder by a high-temperature solid-phase reaction method;
step 21, batching;
weighing lithium chloride and the manganese oxide powder obtained in the first step according to the mass ratio of 1: 1;
step 22, preparing lithium manganese solid powder;
fully and uniformly mixing the lithium chloride and the manganese oxide weighed in the step 21, and placing the mixture in a muffle furnace for high-temperature roasting to obtain lithium-manganese solid powder;
roasting parameters are as follows: the roasting atmosphere is air;
the roasting temperature is 400 ℃;
the roasting time is 48 h;
the lithium manganese solid powder prepared by the step two is Li2MnO3A crystal structure;
step three: preparing a lithium manganese oxide precursor by a selective dissolution method;
step 31, batching;
preparing a dilute sulfuric acid solution with the pH value of 1, and weighing the acid solution and the lithium manganese solid powder obtained in the second step according to the mass ratio of 30: 1;
step 32, preparing a lithium manganese oxide precursor;
fully mixing the diluted sulfuric acid solution weighed in the step 31 with the lithium manganese solid powder, continuously stirring, and carrying out selective dissolution reaction to obtain a lithium manganese oxide precursor;
reaction parameters are as follows: the stirring speed is 500 r/s;
the reaction temperature is 30 ℃;
the reaction time is 12 h;
the precursor powder of the lithium manganese oxide prepared by the step three is epsilon-MnO2A crystal structure;
step four: preparing a lithium potassium manganese composite oxide catalyst by a high-temperature solid-phase reaction method;
step 41, batching;
weighing potassium nitrate and the lithium manganese oxide precursor obtained in the third step according to the mass ratio of 0.1: 1;
step 42, preparation of lithium potassium manganese oxide catalyst
Fully and uniformly mixing the potassium nitrate weighed in the step 41 with the lithium manganese oxide precursor, and placing the mixture in a muffle furnace for high-temperature roasting to obtain Li0.3K0.5Mn8O16A catalyst;
roasting parameters are as follows: the roasting atmosphere is air;
the roasting temperature is 450 ℃;
the roasting time is 24 hours;
li prepared by the fourth step0.3K0.5Mn8O16The catalyst being alpha-MnO2A crystal structure.
Example 4
Preparation of Li2.4K3.75Mn8O16The method of the catalyst comprises the following steps:
step one, preparing manganese oxide powder by a hydrothermal reaction method;
step 11, batching;
weighing ammonium acetate and manganese chloride according to the molar ratio of ammonium to manganese of 1: 1;
step 12, preparing manganese oxide powder;
adding the ammonium acetate and the manganese chloride weighed in the step 11 into deionized water, fully and uniformly mixing, adjusting the pH of the mixed solution by using dilute hydrochloric acid, then transferring the mixed solution into a high-pressure hydrothermal reaction kettle, and placing the high-pressure hydrothermal reaction kettle in a high-temperature constant-temperature furnace for hydrothermal reaction to obtain manganese oxide powder;
reaction parameters are as follows: adjusting the pH of the mixed solution to be less than 1;
the hydrothermal temperature is 110 ℃;
the hydrothermal time is 14 h;
the manganese oxide powder prepared by the step one is alpha-MnO2、β-MnO2And gamma-MnO2A mixed crystal structure in which three crystal structures coexist;
step two: preparing lithium manganese solid powder by a high-temperature solid-phase reaction method;
step 21, batching;
weighing lithium carbonate and the manganese oxide powder obtained in the first step according to the mass ratio of 2.5: 1;
step 22, preparing lithium manganese solid powder;
fully and uniformly mixing the lithium carbonate and the manganese oxide weighed in the step 21, and placing the mixture in a muffle furnace for high-temperature roasting to obtain lithium-manganese solid powder;
roasting parameters are as follows: the roasting atmosphere is air;
the roasting temperature is 600 ℃;
the roasting time is 2 hours;
the lithium manganese solid powder prepared by the step two is Li2MnO3A crystal structure;
step three: preparing a lithium manganese oxide precursor by a selective dissolution method;
step 31, batching;
preparing a mixed acid solution of dilute hydrochloric acid and dilute nitric acid with the pH of 2, and weighing the acid solution and the lithium manganese solid powder obtained in the second step according to the mass ratio of 90: 1; wherein the mass ratio of the dilute hydrochloric acid to the dilute nitric acid is 1: 1;
step 32, preparing a lithium manganese oxide precursor;
fully mixing the mixed acid solution of the dilute hydrochloric acid and the dilute nitric acid weighed in the step 31 with the lithium manganese solid powder, continuously stirring, and carrying out selective dissolution reaction to obtain a lithium manganese oxide precursor;
reaction parameters are as follows: the stirring speed is 800 r/s;
the reaction temperature is 80 ℃;
the reaction time is 36 h;
the precursor powder of the lithium manganese oxide prepared by the step three is epsilon-MnO2A crystal structure;
step four: preparing a lithium potassium manganese composite oxide catalyst by a high-temperature solid-phase reaction method;
step 41, batching;
weighing potassium chloride and the lithium manganese oxide precursor obtained in the third step according to the mass ratio of 0.75: 1;
step 42, preparation of lithium potassium manganese oxide catalyst
Fully and uniformly mixing the lithium chloride weighed in the step 41 with the lithium manganese oxide precursor, and placing the mixture in a muffle furnace for high-temperature roasting to obtain Li2.4K3.75Mn8O16A catalyst;
roasting parameters are as follows: the roasting atmosphere is air;
the roasting temperature is 350 ℃;
the roasting time is 24 hours;
li prepared by the fourth step2.4K3.75Mn8O16The catalyst being alpha-MnO2A crystal structure.
Example 5
Preparation of Li3.2K1.5Mn8O16The method of the catalyst comprises the following steps:
step one, preparing manganese oxide powder by a hydrothermal reaction method;
step 11, batching;
weighing ammonium sulfate, ammonium nitrate, manganese sulfate and manganese nitrate according to the molar ratio of ammonium to manganese of 1: 1; wherein the mass ratio of ammonium persulfate to ammonium nitrate is 1:1, and the mass ratio of manganese sulfate to manganese nitrate is 1: 1;
step 12, preparing manganese oxide powder;
adding the ammonium sulfate, the ammonium nitrate, the manganese sulfate and the manganese nitrate weighed in the step 11 into deionized water, fully and uniformly mixing, adjusting the pH of the mixed solution by using dilute hydrochloric acid, then moving the mixed solution into a high-pressure hydrothermal reaction kettle, and placing the mixed solution into a high-temperature constant-temperature furnace for hydrothermal reaction to obtain manganese oxide powder;
reaction parameters are as follows: adjusting the pH of the mixed solution to be less than 1;
the hydrothermal temperature is 80 ℃;
the hydrothermal time is 4 h;
the manganese oxide powder prepared by the step one is alpha-MnO2、β-MnO2And gamma-MnO2A mixed crystal structure in which three crystal structures coexist;
step two: preparing lithium manganese solid powder by a high-temperature solid-phase reaction method;
step 21, batching;
weighing lithium hydroxide and the manganese oxide powder obtained in the first step according to the mass ratio of 3: 1;
step 22, preparing lithium manganese solid powder;
fully and uniformly mixing the lithium hydroxide and manganese oxide powder weighed in the step 21, and placing the mixture in a muffle furnace for high-temperature roasting to obtain lithium-manganese solid powder;
roasting parameters are as follows: the roasting atmosphere is air;
the roasting temperature is 500 ℃;
the roasting time is 24 hours;
the lithium manganese solid powder prepared by the step two is Li2MnO3A crystal structure;
step three: preparing a lithium manganese oxide precursor by a selective dissolution method;
step 31, batching;
preparing a mixed acid solution of dilute hydrochloric acid and dilute sulfuric acid with the pH of 3, and weighing the acid solution and the lithium manganese solid powder obtained in the second step according to the mass ratio of 100: 1; wherein the mass ratio of the dilute hydrochloric acid to the dilute sulfuric acid is 1: 1;
step 32, preparing a lithium manganese oxide precursor;
fully mixing the mixed acid solution of the dilute hydrochloric acid and the dilute sulfuric acid weighed in the step 31 with the lithium manganese solid powder, continuously stirring, and carrying out selective dissolution reaction to obtain a lithium manganese oxide precursor;
reaction parameters are as follows: the stirring speed is 500 r/s;
the reaction temperature is 40 ℃;
the reaction time is 18 h;
the precursor powder of the lithium manganese oxide prepared by the step three is epsilon-MnO2A crystal structure;
step four: preparing a lithium potassium manganese composite oxide catalyst by a high-temperature solid-phase reaction method;
step 41, batching;
weighing a mixture of potassium chloride and potassium nitrate and the lithium manganese oxide precursor obtained in the third step according to the mass ratio of 0.3: 1; wherein the mass ratio of potassium chloride to potassium nitrate is 1: 1;
step 42, preparation of lithium potassium manganese oxide catalyst
Fully and uniformly mixing the potassium chloride and potassium nitrate mixture weighed in the step 41 with the lithium manganese oxide precursor, and placing the mixture in a muffle furnace for high-temperature roasting to obtain Li3.2K1.5Mn8O16A catalyst;
roasting parameters are as follows: the roasting atmosphere is air;
the roasting temperature is 420 ℃;
the roasting time is 24 hours;
li prepared by the fourth step3.2K1.5Mn8O16The catalyst being alpha-MnO2A crystal structure.
Example 6
Preparation of Li1.0K4.0Mn8O16The method of the catalyst comprises the following steps:
step one, preparing manganese oxide powder by a hydrothermal reaction method;
step 11, batching;
weighing ammonium sulfate, ammonium chloride, manganese sulfate and manganese carbonate according to the molar ratio of ammonium to manganese of 5: 1; wherein the mass ratio of ammonium sulfate to ammonium chloride is 1:1, and the mass ratio of manganese sulfate to manganese carbonate is 1: 1;
step 12, preparing manganese oxide powder;
adding the ammonium sulfate, the ammonium chloride, the manganese sulfate and the manganese carbonate weighed in the step 11 into deionized water, fully and uniformly mixing, adjusting the pH of the mixed solution by using dilute hydrochloric acid, then transferring the mixed solution into a high-pressure hydrothermal reaction kettle, and placing the high-pressure hydrothermal reaction kettle in a high-temperature constant-temperature furnace for hydrothermal reaction to obtain manganese oxide powder;
reaction parameters are as follows: adjusting the pH of the mixed solution to be less than 1;
the hydrothermal temperature is 135 ℃;
the hydrothermal time is 15 h;
the manganese oxide powder prepared by the step one is alpha-MnO2、β-MnO2And gamma-MnO2Mixed crystal structure with three kinds of crystal structures coexistingStructuring;
step two: preparing lithium manganese solid powder by a high-temperature solid-phase reaction method;
step 21, batching;
weighing a mixture of lithium nitrate and lithium sulfate and the manganese oxide powder obtained in the first step according to the mass ratio of 2: 1; wherein the mass ratio of lithium nitrate to lithium sulfate is 1: 1;
step 22, preparing lithium manganese solid powder;
fully and uniformly mixing the mixture of lithium nitrate and lithium sulfate weighed in the step 21 with manganese oxide powder, and placing the mixture in a muffle furnace for high-temperature roasting to obtain lithium-manganese solid powder;
roasting parameters are as follows: the roasting atmosphere is air;
the roasting temperature is 450 ℃;
the roasting time is 12 hours;
the lithium manganese solid powder prepared by the step two is Li2MnO3A crystal structure;
step three: preparing a lithium manganese oxide precursor by a selective dissolution method;
step 31, batching;
preparing a mixed acid solution of dilute hydrochloric acid and dilute nitric acid with the pH of 1, and weighing the acid solution and the lithium manganese solid powder obtained in the second step according to the mass ratio of 130: 1; wherein the mass ratio of the dilute sulfuric acid to the dilute nitric acid is 1: 1;
step 32, preparing a lithium manganese oxide precursor;
fully mixing the mixed acid solution of the dilute hydrochloric acid and the dilute nitric acid weighed in the step 31 with the lithium manganese solid powder, continuously stirring, and carrying out selective dissolution reaction to obtain a lithium manganese oxide precursor;
reaction parameters are as follows: the stirring speed is 1000 r/s;
the reaction temperature is 70 ℃;
the reaction time is 30 h;
the precursor powder of the lithium manganese oxide prepared by the step three is epsilon-MnO2A crystal structure;
step four: preparing a lithium potassium manganese composite oxide catalyst by a high-temperature solid-phase reaction method;
step 41, batching;
weighing a mixture of potassium sulfate and potassium nitrate and the lithium manganese oxide precursor obtained in the third step according to the mass ratio of 0.8: 1;
step 42, preparation of lithium potassium manganese oxide catalyst
Fully and uniformly mixing the potassium sulfate and potassium nitrate mixture weighed in the step 41 with the lithium manganese oxide precursor, and placing the mixture in a muffle furnace for high-temperature roasting to obtain Li1.0K4.0Mn8O16A catalyst;
roasting parameters are as follows: the roasting atmosphere is air;
the roasting temperature is 500 ℃;
the roasting time is 48 h;
li prepared by the fourth step1.0K4.0Mn8O16The catalyst being alpha-MnO2A crystal structure.
Example 7
Preparation of Li1.6K1.0Mn8O16The method of the catalyst comprises the following steps:
step one, preparing manganese oxide powder by a hydrothermal reaction method;
step 11, batching;
weighing ammonium sulfate, ammonium chloride, ammonium nitrate, manganese sulfate, manganese nitrate and manganese carbonate according to the molar ratio of ammonium to manganese of 1:1, wherein the mass ratio of the ammonium sulfate, the ammonium chloride and the ammonium nitrate is 1:1:1, and the mass ratio of the manganese sulfate, the manganese nitrate and the manganese carbonate is 1:1: 1;
step 12, preparing manganese oxide powder;
adding the ammonium sulfate, the ammonium chloride, the ammonium nitrate, the manganese sulfate, the manganese nitrate and the manganese carbonate weighed in the step 11 into deionized water, fully and uniformly mixing, adjusting the pH of the mixed solution by using dilute hydrochloric acid, then moving the mixed solution into a high-pressure hydrothermal reaction kettle, and placing the high-pressure hydrothermal reaction kettle in a high-temperature constant-temperature furnace for hydrothermal reaction to obtain manganese oxide powder;
reaction parameters are as follows: adjusting the pH of the mixed solution to be less than 1;
the hydrothermal temperature is 115 ℃;
the hydrothermal time is 10 h;
the manganese oxide powder prepared by the step one is alpha-MnO2、β-MnO2And gamma-MnO2A mixed crystal structure in which three crystal structures coexist;
step two: preparing lithium manganese solid powder by a high-temperature solid-phase reaction method;
step 21, batching;
weighing a mixture of lithium nitrate, lithium sulfate and lithium carbonate and the manganese oxide powder obtained in the first step according to a mass ratio of 4: 1; wherein the mass ratio of the lithium nitrate to the lithium sulfate to the lithium carbonate is 1:1: 1;
step 22, preparing lithium manganese solid powder;
fully and uniformly mixing the lithium nitrate, the lithium sulfate and the lithium carbonate mixture weighed in the step 21 with a manganese oxide, and placing the mixture in a muffle furnace for high-temperature roasting to obtain lithium-manganese solid powder;
roasting parameters are as follows: the roasting atmosphere is air;
the roasting temperature is 550 ℃;
the roasting time is 28 h;
the lithium manganese solid powder prepared by the step two is Li2MnO3A crystal structure;
step three: preparing a lithium manganese oxide precursor by a selective dissolution method;
step 31, batching;
preparing a mixed acid solution of dilute hydrochloric acid with the pH value of 3, dilute sulfuric acid and dilute nitric acid, and weighing the acid solution and the lithium manganese solid powder obtained in the second step according to the mass ratio of 30: 1; wherein the mass ratio of the dilute hydrochloric acid to the dilute sulfuric acid to the dilute nitric acid is 1:1: 1;
step 32, preparing a lithium manganese oxide precursor;
fully mixing the diluted hydrochloric acid, diluted sulfuric acid and diluted nitric acid mixed acid solution weighed in the step 31 with the lithium manganese solid powder, continuously stirring, and carrying out selective dissolution reaction to obtain a lithium manganese oxide precursor;
reaction parameters are as follows: the stirring speed is 650 r/s;
the reaction temperature is 50 ℃;
the reaction time is 24 h;
the precursor powder of the lithium manganese oxide prepared by the step three is epsilon-MnO2A crystal structure;
step four: preparing a lithium potassium manganese composite oxide catalyst by a high-temperature solid-phase reaction method;
step 41, batching;
weighing a mixture of potassium carbonate, potassium sulfate and potassium nitrate and the lithium manganese oxide precursor obtained in the third step according to the mass ratio of 0.2: 1;
step 42, preparation of lithium potassium manganese oxide catalyst
Fully and uniformly mixing the mixture of potassium carbonate, potassium sulfate and potassium nitrate weighed in the step 41 with the lithium manganese oxide precursor, and placing the mixture in a muffle furnace for high-temperature roasting to obtain Li1.6K1.0Mn8O16A catalyst;
roasting parameters are as follows: the roasting atmosphere is air;
the roasting temperature is 450 ℃;
the roasting time is 14 h;
li prepared by the fourth step1.6K1.0Mn8O16The catalyst being alpha-MnO2A crystal structure.
Example 8
Preparation of Li2.0K3.0Mn8O16The method of the catalyst comprises the following steps:
step one, preparing manganese oxide powder by a hydrothermal reaction method;
step 11, batching;
weighing ammonium persulfate, ammonium sulfate, ammonium chloride, ammonium nitrate, manganese sulfate, manganese nitrate, manganese carbonate and manganese chloride according to the molar ratio of ammonium to manganese being 6: 1; wherein the mass ratio of ammonium persulfate to ammonium sulfate to ammonium chloride to ammonium nitrate is 1:1:1:1, and the mass ratio of manganese sulfate to manganese nitrate to manganese carbonate to manganese chloride is 1:1:1: 1;
step 12, preparing manganese oxide powder;
adding the ammonium sulfate, the ammonium chloride, the ammonium nitrate, the manganese sulfate, the manganese nitrate, the manganese carbonate and the manganese chloride weighed in the step 11 into deionized water, fully and uniformly mixing, adjusting the pH of the mixed solution by using dilute hydrochloric acid, then moving the mixed solution into a high-pressure hydrothermal reaction kettle, and placing the mixed solution into a high-temperature constant-temperature furnace for hydrothermal reaction to obtain manganese oxide powder;
reaction parameters are as follows: adjusting the pH of the mixed solution to be less than 1;
the hydrothermal temperature is 80 ℃;
the hydrothermal time is 4 h;
the manganese oxide powder prepared by the step one is alpha-MnO2、β-MnO2And gamma-MnO2A mixed crystal structure in which three crystal structures coexist;
step two: preparing lithium manganese solid powder by a high-temperature solid-phase reaction method;
step 21, batching;
weighing a mixture of lithium nitrate, lithium sulfate, lithium carbonate and lithium chloride and manganese oxide powder obtained in the step one according to the mass ratio of 2.5: 1; wherein the mass ratio of the lithium nitrate to the lithium sulfate to the lithium carbonate to the lithium chloride is 1:1:1: 1;
step 22, preparing lithium manganese solid powder;
fully and uniformly mixing the lithium nitrate, the lithium sulfate, the lithium carbonate, the lithium chloride mixture and the manganese oxide weighed in the step 21, and placing the mixture in a muffle furnace for high-temperature roasting to obtain lithium-manganese solid powder;
roasting parameters are as follows: the roasting atmosphere is air;
the roasting temperature is 400 ℃;
the roasting time is 35 h;
the lithium manganese solid powder prepared by the step two is Li2MnO3A crystal structure;
step three: preparing a lithium manganese oxide precursor by a selective dissolution method;
step 31, batching;
preparing a dilute hydrochloric acid solution with the pH value of 1, and weighing the acid solution and the lithium manganese solid powder obtained in the second step according to the mass ratio of 115: 1;
step 32, preparing a lithium manganese oxide precursor;
fully mixing the diluted hydrochloric acid solution weighed in the step 31 with the lithium manganese solid powder, continuously stirring, and carrying out selective dissolution reaction to obtain a lithium manganese oxide precursor;
reaction parameters are as follows: the stirring speed is 1000 r/s;
the reaction temperature is 60 ℃;
the reaction time is 28 h;
the precursor powder of the lithium manganese oxide prepared by the step three is epsilon-MnO2A crystal structure;
step four: preparing a lithium potassium manganese composite oxide catalyst by a high-temperature solid-phase reaction method;
step 41, batching;
weighing a mixture of potassium nitrate, potassium carbonate, potassium sulfate and potassium chloride and the lithium manganese oxide precursor obtained in the third step according to the mass ratio of 0.6: 1; wherein the mass ratio of potassium nitrate to potassium carbonate to potassium sulfate to potassium chloride is 1:1:1: 1;
step 42, preparation of lithium potassium manganese oxide catalyst
Fully and uniformly mixing the potassium nitrate, potassium carbonate, potassium sulfate and potassium chloride mixture weighed in the step 41 with the lithium manganese oxide precursor, and placing the mixture in a muffle furnace for high-temperature roasting to obtain Li2.0K3.0Mn8O16A catalyst;
roasting parameters are as follows: the roasting atmosphere is air;
the roasting temperature is 500 ℃;
the roasting time is 48 h;
li prepared by the fourth step2.0K3.0Mn8O16The catalyst being alpha-MnO2A crystal structure.
Example 9
Preparation of Li4.2K4.5Mn8O16The method of the catalyst comprises the following steps:
step one, preparing manganese oxide powder by a hydrothermal reaction method;
step 11, batching;
weighing ammonium persulfate, ammonium sulfate, ammonium chloride, ammonium acetate, ammonium nitrate and manganese nitrate according to the molar ratio of ammonium to manganese of 1: 1; wherein the mass ratio of ammonium persulfate to ammonium sulfate to ammonium chloride to ammonium acetate to ammonium nitrate is 1:1:1:1: 1;
step 12, preparing manganese oxide powder;
adding the ammonium persulfate, the ammonium sulfate, the ammonium chloride, the ammonium acetate, the ammonium nitrate and the manganese sulfate weighed in the step 11 into deionized water, fully and uniformly mixing, adjusting the pH of the mixed solution by using dilute hydrochloric acid, then moving the mixed solution into a high-pressure hydrothermal reaction kettle, and placing the high-pressure hydrothermal reaction kettle in a high-temperature constant-temperature furnace for hydrothermal reaction to obtain manganese oxide powder;
reaction parameters are as follows: adjusting the pH of the mixed solution to be less than 1;
the hydrothermal temperature is 145 ℃;
the hydrothermal time is 4 h;
the manganese oxide powder prepared by the step one is alpha-MnO2、β-MnO2And gamma-MnO2A mixed crystal structure in which three crystal structures coexist;
step two: preparing lithium manganese solid powder by a high-temperature solid-phase reaction method;
step 21, batching;
weighing a mixture of lithium nitrate, lithium sulfate, lithium carbonate, lithium chloride and lithium hydroxide and the manganese oxide powder obtained in the step one according to the mass ratio of 0.1: 1; wherein the mass ratio of lithium nitrate to lithium sulfate to lithium carbonate to lithium chloride to lithium hydroxide is 1:1:1:1: 1;
step 22, preparing lithium manganese solid powder;
fully and uniformly mixing the lithium nitrate, the lithium sulfate, the lithium carbonate, the lithium chloride and the lithium hydroxide mixture weighed in the step 21 with a manganese oxide, and placing the mixture in a muffle furnace for high-temperature roasting to obtain lithium-manganese solid powder;
roasting parameters are as follows: the roasting atmosphere is air;
the roasting temperature is 480 ℃;
the roasting time is 22 h;
the lithium manganese solid powder prepared by the step two is Li2MnO3A crystal structure;
step three: preparing a lithium manganese oxide precursor by a selective dissolution method;
step 31, batching;
preparing a dilute sulfuric acid solution with the pH of 2, and weighing the acid solution and the lithium manganese solid powder obtained in the second step according to the mass ratio of 55: 1;
step 32, preparing a lithium manganese oxide precursor;
fully mixing the diluted sulfuric acid solution weighed in the step 31 with the lithium manganese solid powder, continuously stirring, and carrying out selective dissolution reaction to obtain a lithium manganese oxide precursor;
reaction parameters are as follows: the stirring speed is 800 r/s;
the reaction temperature is 60 ℃;
the reaction time is 2 h;
the precursor powder of the lithium manganese oxide prepared by the step three is epsilon-MnO2A crystal structure;
step four: preparing a lithium potassium manganese composite oxide catalyst by a high-temperature solid-phase reaction method;
step 41, batching;
weighing a mixture of potassium chloride and potassium carbonate and the lithium manganese oxide precursor obtained in the third step according to the mass ratio of 0.1: 1; wherein the mass ratio of potassium chloride to potassium carbonate is 1: 1;
step 42, preparation of lithium potassium manganese oxide catalyst
Fully and uniformly mixing the potassium chloride and potassium carbonate mixture weighed in the step 41 with the lithium manganese oxide precursor, and placing the mixture in a muffle furnace for high-temperature roasting to obtain Li4.2K4.5Mn8O16A catalyst;
roasting parameters are as follows: the roasting atmosphere is air;
the roasting temperature is 550 ℃;
the roasting time is 12 hours;
li prepared by the fourth step4.2K4.5Mn8O16The catalyst being alpha-MnO2A crystal structure.
Comparative example 1
Except that the manganese oxide prepared in the step one is replaced by commercial MnO2(product No. A10765 manufactured by Alfa Aesar Co., Ltd.)) Otherwise, the procedure was the same as in example 3, and the catalyst thus obtained was designated as Li0.8K2.5Mn8O16(commercial).
Li prepared in comparative example 10.8K2.5Mn8O16(commercial) catalyst powder the catalyst powder was subjected to structural analysis using an X-ray diffractometer model Rigaku D/MAX-2200 of Japan, as shown in FIG. 5, and was beta-MnO2A crystal structure.
Comparative example 2
The procedure was as in example 3 except that no lithium source was used in step two, and the catalyst obtained was labeled as K2.5Mn8O16。
K obtained in comparative example 22.5Mn8O16The catalyst powder was subjected to structural analysis using an X-ray diffractometer model Rigaku D/MAX-2200 of Japan, as shown in FIG. 6, and was α -MnO2A crystal structure.
Comparative example 3
The procedure is as in example 3 except that in step four, no potassium source is used, and the catalyst obtained is labelled Li0.8Mn8O16。
Vs. Li prepared in comparative example 30.8Mn8O16The catalyst powder was subjected to structural analysis using an X-ray diffractometer model Rigaku D/MAX-2200 of Japan, as shown in FIG. 7, and was β -MnO2A crystal structure.
And (3) testing the performance of the catalyst: the ozone catalytic activity of a manganese series ozone decomposition catalyst activity experimental method (HG/T5419-2018) catalyst is adopted for evaluation, and the test conditions are as follows: the catalyst is placed in a continuous flow fixed bed device, the reaction pressure is normal pressure, the temperature is 25 ℃, the relative humidity is 90 percent, and the space velocity is 660000h-1The ozone concentration was 45ppm and the test time was 6 h. The regeneration conditions of the heat treatment of the deactivated catalyst are as follows: the heat treatment atmosphere is air, the heat treatment temperature is 500 ℃, and the heat treatment time is 1 h. The test results are shown in table 1.
TABLE 1 evaluation of ozonolysis degradation Activity of each catalyst
Figure BDA0002459596840000211
From examples 1 to 9, it can be seen that when the lithium content or potassium content of the catalyst is too low or too high, the catalytic decomposition activity of ozone is not high; the catalytic activity of the lithium potassium manganese complex oxide is best when the lithium or potassium content reaches a certain amount. The results of 5 times of reaction-repeated regeneration tests on the catalyst show that the ozone decomposition efficiency of the catalyst can be restored to be more than 90 percent of the original ozone decomposition efficiency, and the catalyst shows good repeated use stability.
As can be seen from the comparison of comparative example 1 and example 1, if the manganese oxide prepared in the first alternative step is commercially available MnO2(product No. A10765, manufactured by Alfa Aesar Co., Ltd.) the crystal structure of the catalyst prepared in comparative example 1 was changed to beta-MnO2Not alpha-MnO in example 12The structure, resulting in a significant change in physicochemical properties, was poor in catalytic activity of ozone and stability against repeated use exhibited in comparative example 1.
As can be seen from the comparison of comparative example 2, comparative example 3 and example 1, if a lithium source or a potassium source is not used in step two or step three, the chemical composition and crystal structure of the prepared catalyst are somewhat different from those of example 1, and thus the catalysts prepared in comparative examples 2 and 3 have somewhat different physicochemical properties from those of example 1, and thus the catalysts of comparative examples 2 and 3 exhibit poor ozone catalytic performance and reuse stability.
The applicant states that the preparation method and application of the potassium manganese composite oxide catalyst according to the present invention do not mean that the operation procedures of the above examples are necessarily relied upon for implementation. It should be apparent to those skilled in the art that any modifications to the present invention, including raw materials, manufacturing processes, specific operating methods, and methods of practice, are within the scope and disclosure of the present invention.

Claims (5)

1. A preparation method of a lithium potassium manganese composite oxide catalyst for ozonolysis, which can be regenerated by heating, is characterized by comprising the following steps:
step one, preparing manganese oxide powder by a hydrothermal reaction method;
step 11, batching;
weighing an ammonium source and a manganese source according to a certain molar ratio of ammonium to manganese;
the molar ratio of ammonium to manganese of the ammonium source and the manganese source is 1: 1-10: 1;
the ammonium source is any one of ammonium persulfate, ammonium sulfate, ammonium chloride, ammonium acetate and ammonium nitrate or a mixture of at least two of the ammonium sources in any mass ratio;
the manganese source is any one of manganese sulfate, manganese nitrate, manganese carbonate and manganese chloride or a mixture of at least two of manganese sulfate, manganese nitrate, manganese carbonate and manganese chloride in any mass ratio;
step 12, preparing manganese oxide powder;
adding the ammonium source and the manganese source weighed in the step 11 into deionized water, fully and uniformly mixing, adjusting the pH of the mixed solution by using dilute hydrochloric acid, then transferring into a high-pressure hydrothermal reaction kettle, and placing into a high-temperature constant-temperature furnace for hydrothermal reaction to obtain manganese oxide powder;
reaction parameters are as follows: adjusting the pH of the mixed solution to be less than 1;
the hydrothermal temperature is 80-150 ℃;
the hydrothermal time is 4-20 h;
the manganese oxide powder prepared by the step one is alpha-MnO2、β-MnO2And gamma-MnO2A mixed crystal structure in which three crystal structures coexist;
step two: preparing lithium manganese solid powder by a high-temperature solid-phase reaction method;
step 21, batching;
weighing a lithium source and the manganese oxide powder prepared in the first step according to a certain mass ratio;
the mass ratio of the lithium source to the manganese oxide is 0.1: 1-5: 1;
the lithium source is one or a mixture of at least two of lithium sulfate, lithium nitrate, lithium chloride, lithium carbonate and lithium hydroxide in any mass ratio;
step 22, preparing lithium manganese solid powder;
fully and uniformly mixing the lithium source and the manganese oxide weighed in the step 21, and placing the mixture in a muffle furnace for high-temperature roasting to obtain lithium-manganese solid powder;
roasting parameters are as follows: the roasting atmosphere is air;
the roasting temperature is 400-600 ℃;
the roasting time is 2-48 h;
the lithium manganese solid powder prepared by the step two is Li2MnO3A crystal structure;
step three: preparing a lithium manganese oxide precursor by a selective dissolution method;
step 31, batching;
preparing an acid solution with a certain pH value, and weighing the acid solution and the lithium manganese solid powder prepared in the second step according to a certain mass ratio;
the pH value of the acid solution is 1-3;
the acid solution is one of dilute sulfuric acid, dilute hydrochloric acid and dilute nitric acid or a mixture of at least two of the dilute sulfuric acid, the dilute hydrochloric acid and the dilute nitric acid in any mass ratio;
the mass ratio of the acid solution to the lithium manganese solid powder is 30: 1-150: 1;
step 32, preparing a lithium manganese oxide precursor;
fully mixing the acid solution weighed in the step 31 with the lithium manganese solid powder, continuously stirring, and carrying out selective dissolution reaction to obtain a lithium manganese oxide precursor;
reaction parameters are as follows: the stirring speed is 300-1500 r/s;
the reaction temperature is 20-90 ℃;
the reaction time is 2-48 h;
the precursor powder of the lithium manganese oxide prepared by the step three is epsilon-MnO2A crystal structure;
step four: preparing a lithium potassium manganese composite oxide catalyst by a high-temperature solid-phase reaction method;
step 41, batching;
weighing a potassium source and the lithium manganese oxide precursor prepared in the third step according to a certain mass ratio;
the potassium source is any one of potassium nitrate, potassium carbonate, potassium sulfate or potassium chloride or a mixture of at least two of potassium nitrate, potassium carbonate, potassium sulfate and potassium chloride in any mass ratio;
the mass ratio of the potassium source to the lithium manganese oxide is 0.1: 1-1: 1
Step 42, preparation of lithium potassium manganese oxide catalyst
Fully and uniformly mixing the potassium source weighed in the step 41 with the lithium manganese oxide precursor, and placing the mixture in a muffle furnace for high-temperature roasting to obtain LiaKbMn8O16A catalyst;
roasting parameters are as follows: the roasting atmosphere is air;
the roasting temperature is 350-750 ℃;
the roasting time is 2-48 h;
li prepared by the fourth stepaKbMn8O16The catalyst being alpha-MnO2A crystal structure.
2. The method for preparing a lithium potassium manganese complex oxide catalyst for ozonolysis by heating regeneration according to claim 1, wherein: the prepared lithium potassium manganese composite oxide catalyst is used for decomposing ozone.
3. The method for preparing a lithium potassium manganese complex oxide catalyst for ozonolysis by heating regeneration according to claim 1, wherein: the prepared lithium potassium manganese composite oxide catalyst is placed in a continuous flow fixed bed device, the reaction pressure is normal pressure, and the reaction space velocity is 660000h-1The concentration of ozone in the mixed gas is 45ppm, the reaction temperature is room temperature, the reaction humidity is 90 percent, and the reaction time is 6 hours.
4. The method for preparing a lithium potassium manganese complex oxide catalyst for ozonolysis by heating regeneration according to claim 1, wherein: the conditions of heating regeneration are as follows: the atmosphere is air, the heat treatment temperature is 500 ℃, and the heat treatment time is 1 h.
5. The method for preparing a lithium potassium manganese complex oxide catalyst for ozonolysis by heating regeneration according to claim 1, wherein: after regeneration treatment, the ozone decomposition rate of the lithium potassium manganese composite oxide catalyst can be recovered to more than 90% before regeneration.
CN202010316417.4A 2020-04-21 2020-04-21 Lithium potassium manganese composite oxide catalyst capable of being regenerated in heating mode and used for ozonolysis and preparation method thereof Active CN111545191B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202010316417.4A CN111545191B (en) 2020-04-21 2020-04-21 Lithium potassium manganese composite oxide catalyst capable of being regenerated in heating mode and used for ozonolysis and preparation method thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202010316417.4A CN111545191B (en) 2020-04-21 2020-04-21 Lithium potassium manganese composite oxide catalyst capable of being regenerated in heating mode and used for ozonolysis and preparation method thereof

Publications (2)

Publication Number Publication Date
CN111545191A CN111545191A (en) 2020-08-18
CN111545191B true CN111545191B (en) 2021-07-30

Family

ID=72000278

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202010316417.4A Active CN111545191B (en) 2020-04-21 2020-04-21 Lithium potassium manganese composite oxide catalyst capable of being regenerated in heating mode and used for ozonolysis and preparation method thereof

Country Status (1)

Country Link
CN (1) CN111545191B (en)

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105727939A (en) * 2016-04-08 2016-07-06 济南大学 Potassium and manganese composite oxide and preparing method and application thereof to diesel vehicle tail gas purification
JP2018078103A (en) * 2016-11-02 2018-05-17 株式会社豊田自動織機 Non-aqueous secondary battery and gassing inhibitor used for same, and non-aqueous electrolyte solution
CN107970947A (en) * 2017-11-30 2018-05-01 宁波智通环保科技有限公司 The catalyst and its manufacture method of a kind of ozone decomposition
KR102116774B1 (en) * 2018-09-21 2020-05-29 한국화학연구원 Catalyst for reducing ozone and its manufacturing method
CN109225218B (en) * 2018-11-13 2021-05-28 中国科学院生态环境研究中心 Silver-manganese oxide composite catalyst, preparation method and application thereof
CN110420636B (en) * 2019-08-30 2021-10-19 广州大学 Lanthanum-modified manganese oxide catalyst, and preparation method and application thereof

Also Published As

Publication number Publication date
CN111545191A (en) 2020-08-18

Similar Documents

Publication Publication Date Title
CN108435160B (en) Cerium-manganese catalyst for decomposing ozone at wide temperature and high airspeed, preparation method and application
CN107029702B (en) Manganese oxide-loaded carbon fiber felt catalyst material and preparation method and application thereof
CN111905719B (en) Manganese-based catalyst and preparation method thereof
CN113231009B (en) Ammonia adsorbent and preparation method thereof
CN113042036A (en) Preparation method and application of cerium modified amorphous manganese oxide catalyst
CN109745987A (en) The preparation method and application of strontium cobalt-based properties of perovskite mixed-oxide oxygen carrier
CN111545191B (en) Lithium potassium manganese composite oxide catalyst capable of being regenerated in heating mode and used for ozonolysis and preparation method thereof
CN1546231A (en) Catalyst for removing nitrogen oxide through selective catalytic reduction and its preparation method
CN112246268A (en) Novel efficient ozone catalytic material and preparation method thereof
CN107469811A (en) A kind of wide temperature window denitrating catalyst and its preparation method and application
CN112221488A (en) Novel core-shell structure catalyst for synergistic denitration and demercuration and preparation method thereof
CN110697768A (en) Mesoporous TiO 22Material, catalyst, preparation method of material and catalyst, and denitration method
CN110586178B (en) SAPO-34 molecular sieve and Cu/SAPO-34 denitration catalyst, preparation method and application thereof, and denitration method
CN109589910A (en) The preparation method and application of barium cobalt-based properties of perovskite mixed-oxide oxygen carrier
CN113117639B (en) Modified molecular sieve adsorbent and preparation method and application thereof
CN114653356A (en) Preparation method of lanthanum-doped cerium dioxide catalyst material and formaldehyde-removing compound
CN111250078B (en) MnOx @ Eu-CeOx low-temperature SCR flue gas denitration catalyst and preparation method and application thereof
WO2021217722A1 (en) Medium/low temperature supported nano copper oxide particle catalyst and preparation method therefor and application thereof
CN109772346B (en) Preparation method of composite material catalyst and application of composite material catalyst in denitrification at low temperature
CN109248648B (en) Modified bauxite for adsorbing heavy metal ions in wastewater
CN113351158A (en) Zeolite molecular sieve adsorbing material for concentrating VOCs (volatile organic compounds), and preparation method and application thereof
CN111821942A (en) High-efficiency dioxin adsorbent for waste incineration and preparation method and application thereof
CN112108115A (en) Preparation method and testing device of carbon-based composite material for catalyzing and degrading multiple organic matters at room temperature
CN111514887A (en) α -MnO with exposed specific crystal face2Alpha crystal form metal oxide catalyst and preparation method thereof
CN109529795A (en) A kind of hydrogen sulfide adsorbent and preparation method thereof

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