CN111974379B - As-MnO X Composite oxide and process for producing the same - Google Patents
As-MnO X Composite oxide and process for producing the same Download PDFInfo
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- CN111974379B CN111974379B CN202010786209.0A CN202010786209A CN111974379B CN 111974379 B CN111974379 B CN 111974379B CN 202010786209 A CN202010786209 A CN 202010786209A CN 111974379 B CN111974379 B CN 111974379B
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- 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
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- 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
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- B01J23/34—Manganese
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- C—CHEMISTRY; METALLURGY
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Abstract
The invention relates to an As-MnO X The preparation method of the composite oxide comprises the following steps: (1) Evenly mixing manganese sesquioxide powder and manganese arsenide powder, and sieving to obtain a mixture; (2) Placing the mixture obtained in the step (1) into a reactor, heating to 600-800 ℃, preserving heat for 80-120 min, and then cooling along with a furnace to obtain As-MnO X A composite oxide. The method of the invention adopts a vacuum sintering method, the evenly mixed mixture is put into a vacuum sintering furnace, and the As-MnO with different relative contents of oxygen vacancies can be obtained by controlling the sintering temperature and the sintering time X A composite oxide; the method has low cost and simple operation, and can control As-MnO by controlling the relative content of oxygen vacancies X Catalytic oxidation performance of the composite oxide.
Description
Technical Field
The invention relates to the technical field of catalytic material preparation, in particular to an As-MnO X Composite oxide and its preparation method are provided.
Background
Transition metal oxides are of interest to many researchers because of their low cost, wide sources, and certain catalytic capabilities. Wherein Mn can have interconversion of multiple valence states in chemical reaction, so that the Mn has better catalytic activity. Manganese oxide is therefore one of the most interesting metal oxides. Research shows that oxygen vacancies on metal oxides are one of the important factors affecting catalytic performance because of the existence of unsaturated coordination structures around the metal oxides, which are very conducive to oxygen activation.
Currently, methods for constructing oxygen vacancies include high temperature quenching, material compounding, ion doping, etc., wherein the ion doping method is widely used because of its low cost and simple process. The chinese patent with the publication number CN 107694559B discloses a method for preparing a zinc-manganese oxide-trimanganese tetroxide composite oxide with adjustable oxygen vacancies by performing a hydrothermal reaction and then performing a heating reaction and finally performing roasting, but the preparation method still has complex procedures and risks of introducing impurities.
As-doped manganese oxides, in theory, possess both redox couples-Mn 2+ /Mn 3+ And As 3+ /As 5+ Has more rapid oxygen activation and oxygen transport capacity than a single redox pair catalyst. However, a method of doping arsenic ions into manganese oxide to compete with manganese for oxygen at high temperature and changing the relative contents of the valence states of each positive valence ion to construct oxygen vacancies has not been reported yet.
Thus, an As-MnO was developed X The compound and the preparation method thereof have good practical significance.
Disclosure of Invention
The invention aims to provide an As-MnO X Composite oxide and its preparation method are provided. The preparation method adopts a vacuum sintering method, the evenly mixed mixture is put into a vacuum sintering furnace, and the As-MnO with controllable relative content of oxygen vacancies can be obtained by controlling the sintering temperature and the sintering time X A composite oxide. The method has low cost and simple operation, and can control As-MnO by controlling the relative content of oxygen vacancies X Catalytic oxidation performance of the composite oxide.
In order to achieve the above purpose, the technical scheme adopted by the invention is as follows: as-MnO X The preparation method of the composite oxide is characterized by comprising the following steps:
(1) Under the protection of protective gas, evenly mixing manganese sesquioxide powder and manganese arsenide powder, and sieving to obtain a mixture;
(2) Placing the mixture obtained in the step (1) into a reactor, heating to 600-800 ℃, preserving heat for 80-120 min, and then cooling along with a furnace to obtain As-MnO X A composite oxide. Wherein 1 is<X<4/3。
As a further improvement of the invention, in the step (1), the mass ratio of the manganese sesquioxide powder to the manganese arsenide powder is 3.35:1.
As a further improvement of the invention, in the step (2), the heating rate is 5-15 ℃/min.
As a further improvement of the invention, in the step (1), the mixing time is 4-6 h.
As a further improvement of the invention, in the step (1), the screen mesh in the sieving operation process is 100-200 meshes.
As a further improvement of the present invention, in the step (1), the manganese sesquioxide powder has a particle size of 200 mesh and a purity of 3N.
As a further improvement of the invention, the granularity of the manganese arsenide powder is 150 meshes, and the purity is 3N.
As a further improvement of the present invention, in the step (2), the reactor is a vacuum sintering furnace.
As a further improvement of the present invention, in the step (1), the shielding gas is nitrogen or an inert gas.
At the same time propose an As-MnO X Composite oxide using As-MnO As described above X The composite oxide is prepared by a preparation method.
Compared with the prior art, the invention has the beneficial effects that: in the reaction process, a vacuum sintering method is adopted, the mixture which is uniformly mixed is put into a vacuum sintering furnace for sintering, so that arsenic ions and manganese ions compete for capturing oxygen ions at high temperature, and Mn can be controlled by controlling the heating temperature and the heat preservation time 2+ /Mn 3+ And As 3+ /As 5+ The relative content of each ion in the two redox pairs is controlled, so that the relative content of oxygen vacancies is controlled, and the catalytic oxidation performance is controlled.
Drawings
Figure 1 is an XRD pattern of examples 1, 2 and 3 of the present invention.
FIG. 2 is an XPS plot of Mn2p for examples 1, 2 and 3 of the present invention.
FIG. 3 shows the relative amounts of Mn in different valence states for examples 1, 2 and 3 according to the present invention.
FIG. 4 is an XPS plot of As3d for examples 1, 2 and 3 of the present invention.
FIG. 5 shows the relative amounts of the various valence states of As for examples 1, 2 and 3 of the present invention.
FIG. 6 is an XPS plot of O1s for examples 1, 2 and 3 of the present invention.
FIG. 7 shows the relative amounts of different particles of O according to examples 1, 2 and 3 of the present invention.
Detailed Description
For a better description of the objects, technical solutions and advantages of the present invention, the present invention will be further described with reference to the following specific examples.
The invention provides an As-MnO X A method for producing a composite oxide, the method comprising the steps of:
(1) Evenly mixing manganese sesquioxide powder and manganese arsenide powder, and sieving to obtain a mixture;
(2) Placing the mixture obtained in the step (1) into a reactor, heating to 600-800 ℃, preserving heat for 80-120 min, and then cooling along with a furnace to obtain As-MnO X A composite oxide.
The invention provides an As-MnO X Preparation method of composite oxide powder capable of controlling As-MnO X The relative content of oxygen vacancies in the composite oxide powder is controlled, thereby controlling the catalytic oxidation performance thereof.
In certain embodiments of the present invention, in step (1), the mass ratio of the manganese sesquioxide powder to the manganese arsenide powder is 3.35:1. Further, in other embodiments of the present invention, the mass ratio of the manganese sesquioxide powder to the manganese arsenide powder is 2.5-7.5:1, and As-MnO can be obtained As well X Composite oxide powder.
In some embodiments of the present invention, in the step (2), the heating rate is 5 to 15 ℃/min. Too slow or too fast temperature rise can cause serious phase transition of manganese sesquioxide, and the relative content of oxygen vacancies cannot be well controlled.
In some embodiments of the present invention, in the step (1), the mixing time is 4 to 6 hours. Too short mixing time can lead to uneven powder mixing and larger relative content of redox pairs at different parts after sintering. Too short mixing time can also cause uneven distribution of the relative content of oxygen vacancies, and the relative content of the oxygen vacancies cannot be controlled; too long mixing time can cause too fine agglomeration of powder to be screened, and the agglomeration of the powder can cause uneven distribution of oxygen vacancies after sintering, so that the aim of controlling the relative content of the oxygen vacancies can not be achieved.
As a further improvement of the invention, in the step (1), the screen mesh in the sieving operation process is 100-200 meshes. The manganese oxide powder and the manganese arsenide powder with proper granularity can lead the reaction to be carried out smoothly, and oxygen vacancies after sintering are distributed uniformly.
As a further improvement of the present invention, in the step (1), the manganese sesquioxide powder has a particle size of 200 mesh and a purity of 3N.
As a further improvement of the invention, the granularity of the manganese arsenide powder is 150 meshes, and the purity is 3N.
As a further improvement of the present invention, in the step (2), the reactor is a vacuum sintering furnace.
As a further improvement of the present invention, in the step (1), the shielding gas is nitrogen or an inert gas. The existence of the protective gas can avoid the influence of air on the reaction.
At the same time propose an As-MnO X Composite oxide using As-MnO As described above X The composite oxide is prepared by a preparation method.
As a preferred embodiment of the preparation method of the present invention, further step (3): the As-MnO obtained in the step (2) is treated X Crushing the composite oxide into powder, and sieving to obtain As-MnO X Composite oxide powder. Further, the mesh number of the sieving screen is 100-325 mesh.
Example 1.
As-MnO X The preparation method of the composite oxide comprises the following steps:
(1) Under the protection of helium, 770g of manganese sesquioxide powder with the granularity of 200 meshes and 230g of manganese arsenide powder with the granularity of 150 meshes are mixed in a mixer for 4 hours and pass through a 100-mesh screen to obtain a mixture;
(2) Placing the mixture obtained in the step (1) into a vacuum sintering furnace, vacuumizing, and heating to 600 ℃ at a heating rate of 5 ℃/minPreserving heat for 80min, and cooling with furnace to obtain As-MnO X A composite oxide.
The As-MnO obtained X Crushing the composite oxide into powder, and sieving with 100 mesh sieve to obtain As-MnO with proper particle size X Composite oxide powder.
As-MnO prepared in this example X The composite oxide powder is marked As-MnO X 600 ℃. The XRD pattern of the synthesized composite oxide is shown in FIG. 1. As can be seen from the figure, the synthesized powder was As-MnO X Composite oxide in which MnO X Is MnO and Mn 3 O 4 And a relatively low MnO content; as can be seen from the X-ray photoelectron spectrum of Mn2p shown in FIG. 2 and the relative content of positive ions of manganese shown in FIG. 3, the manganese valence state of the synthesized product is positive 2 valence and positive 3 valence, and has lower Mn 2+ The content is as follows; as can be seen from the XPS diagram of As3d shown in FIG. 4 and the relative content of positive ions of arsenic shown in FIG. 5, the valence state of arsenic of the synthesized product is positive 3 and positive 5, and the synthesized product has lower As 5+ The content is as follows; from the XPS chart of O1s shown in FIG. 6 and the relative content of each particle of O shown in FIG. 7, the synthesized product has lower metal-O bond and oxygen vacancy (V O ) Concentration.
Example 2.
As-MnO X The preparation method of the composite oxide comprises the following steps:
(1) Under the protection of helium, 770g of manganese sesquioxide powder with the granularity of 200 meshes and 230g of manganese arsenide powder with the granularity of 150 meshes are mixed in a mixer for 5 hours and then pass through a 150-mesh screen to obtain a mixture;
(2) Placing the mixture obtained in the step (1) into a vacuum sintering furnace, vacuumizing, heating to 700 ℃ at a heating rate of 10 ℃/min, preserving heat for 100min, and cooling along with the furnace to obtain As-MnO X A composite oxide.
The As-MnO obtained X Crushing the composite oxide into powder, and sieving with 200 mesh sieve to obtain As-MnO with proper particle size X Composite oxide powder.
As-MnO prepared in this example X The composite oxide powder is marked As-MnO X 700 ℃. As can be seen from the XRD pattern in FIG. 1, the synthesized powder is As-MnO X Composite oxide in which MnO X Is MnO and Mn 3 O 4 And the relative content of MnO is high; as can be seen from FIGS. 2 and 3, the manganese of the synthesized product has positive 2-valent and positive 3-valent manganese and higher Mn 2+ The content is as follows; as can be seen from FIGS. 4 and 5, the arsenic in the synthesized product has a valence state of positive 3 and positive 5, and has a high As 5+ The content is as follows; from the XPS chart of O1s shown in FIG. 6 and the relative content of each particle of O shown in FIG. 7, the synthesized product has higher metal-O bond and oxygen vacancy (V O ) Concentration.
Example 3.
As-MnO X The preparation method of the composite oxide comprises the following steps:
(1) Under the protection of helium, 770g of manganese sesquioxide powder with the granularity of 200 meshes and 230g of manganese arsenide powder with the granularity of 150 meshes are mixed in a mixer for 6 hours and pass through a 200-mesh screen to obtain a mixture;
(2) Placing the mixture obtained in the step (1) into a vacuum sintering furnace, vacuumizing, heating to 800 ℃ at a heating rate of 15 ℃/min, preserving heat for 120min, and cooling along with the furnace to obtain As-MnO X A composite oxide.
The As-MnO obtained X Crushing the composite oxide into powder, and sieving with 325 mesh sieve to obtain As-MnO with proper particle size X Composite oxide powder.
As-MnO prepared in this example X The composite oxide powder is marked As-MnO X 800 ℃. As can be seen from FIG. 1, the synthesized powder is As-MnO X Composite oxide in which MnO X Is MnO and Mn 3 O 4 And the relative content of MnO is high; as can be seen from FIGS. 2 and 3, the manganese of the synthesized product has positive 2-valent and positive 3-valent manganese and has high Mn 2+ The content is as follows; as can be seen from FIGS. 4 and 5, the valence state of arsenic in the synthesized product is positive 3 and positive 5, and has high As 5+ The content is as follows; each pellet of O shown in fig. 7 and the XPS diagram of O1s shown in fig. 6The relative content of the subunits is known, and the synthesized product has high metal-O bond and oxygen vacancy (V O ) Concentration. The particle distribution of O contains water (H 2 O), which may originate from water vapor in the air.
As can be seen from examples 1 to 3, in this process, as the sintering temperature and time are changed, the concentration of oxygen vacancies is changed accordingly, resulting in oxygen vacancies at different temperatures (V as in FIG. 7 O ) The relative content of (2) is shown.
Compared with the prior art, the invention has the beneficial effects that: in the reaction process, a vacuum sintering method is adopted, the mixture which is uniformly mixed is put into a vacuum sintering furnace for sintering, so that arsenic ions and manganese ions compete for capturing oxygen ions at high temperature, and Mn can be controlled by controlling the heating temperature and the heat preservation time 2+ /Mn 3+ And As 3+ /As 5+ The relative content of each ion in the two redox pairs is controlled, so that the relative content of oxygen vacancies is controlled, and the catalytic oxidation performance is controlled.
Finally, it should be noted that the above embodiments are only for illustrating the technical solution of the present invention and not for limiting the scope of the present invention, and although the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that the technical solution of the present invention may be modified or substituted equally without departing from the spirit and scope of the technical solution of the present invention.
Claims (3)
1. As-MnO X The preparation method of the composite oxide is characterized by comprising the following steps:
(1) Under the protection of nitrogen or inert gas, evenly mixing manganese sesquioxide powder and manganese arsenide powder, wherein the granularity of the manganese sesquioxide powder is 200 meshes, the purity is 3N, the granularity of the manganese arsenide powder is 150 meshes, the purity is 3N, the mass ratio of the manganese sesquioxide powder to the manganese arsenide powder is 2.5-7.5:1, the mixing time is 4-6 h, and then sieving is carried out, wherein the mesh screen in the sieving operation process is 100-200 meshes, so as to obtain a mixture;
(2) Placing the mixture obtained in the step (1) into a vacuum sintering furnace, heating to 600-800 ℃, and heatingThe speed is 5-15 ℃/min, the temperature is kept for 80-120 min, arsenic ions and manganese ions compete for capturing oxygen ions at high temperature, and Mn is controlled 2+ /Mn 3+ And As 3+ /As 5+ The relative content of each ion in the two redox pairs is cooled along with the furnace to obtain As-MnO X Composite oxide, 1<X<4/3。
2. The method according to claim 1, wherein in the step (1), the mass ratio of the manganese sesquioxide powder to the manganese arsenide powder is 3.35:1.
3. As-MnO X A composite oxide characterized by using the As-MnO according to any one of claims 1 to 2 X The composite oxide is prepared by a preparation method.
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| CN202010786209.0A CN111974379B (en) | 2020-08-07 | 2020-08-07 | As-MnO X Composite oxide and process for producing the same |
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Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002373459A (en) * | 2001-06-14 | 2002-12-26 | Sumitomo Metal Mining Co Ltd | Sputtering target for optical disk protecting film, and the optical disk protecting film formed by using the same |
| CN101978431A (en) * | 2008-03-25 | 2011-02-16 | 旭硝子株式会社 | Electric conductor and process for its production |
| CN105047738A (en) * | 2015-06-30 | 2015-11-11 | 厦门神科太阳能有限公司 | Sputtering target material and CIGS-based thin-film solar cell made of same |
| CN110224118A (en) * | 2019-05-15 | 2019-09-10 | 桂林电子科技大学 | Compound manganese and oxygen compound film and the preparation method and application thereof |
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2020
- 2020-08-07 CN CN202010786209.0A patent/CN111974379B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002373459A (en) * | 2001-06-14 | 2002-12-26 | Sumitomo Metal Mining Co Ltd | Sputtering target for optical disk protecting film, and the optical disk protecting film formed by using the same |
| CN101978431A (en) * | 2008-03-25 | 2011-02-16 | 旭硝子株式会社 | Electric conductor and process for its production |
| CN105047738A (en) * | 2015-06-30 | 2015-11-11 | 厦门神科太阳能有限公司 | Sputtering target material and CIGS-based thin-film solar cell made of same |
| CN110224118A (en) * | 2019-05-15 | 2019-09-10 | 桂林电子科技大学 | Compound manganese and oxygen compound film and the preparation method and application thereof |
Non-Patent Citations (1)
| Title |
|---|
| 孙智 等.1.《材料概论》.2008, * |
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