CN114351184A - Perovskite type composite catalyst and preparation method and application thereof - Google Patents
Perovskite type composite catalyst and preparation method and application thereof Download PDFInfo
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Abstract
The invention discloses a perovskite type composite catalyst and a preparation method and application thereof, wherein the perovskite type composite catalyst comprises a perovskite material, and nano metal particles are distributed on the surface of the perovskite material; the perovskite material has the following chemical formula: la0.9Co1‑δFeδO6(ii) a Wherein, delta is more than 0 and less than 1; the nano metal particles comprise at least one of nano lanthanum particles, nano cobalt particles and nano iron particles. According to the invention, the nano metal particles are formed on the surface of the perovskite material, so that a new active site is provided for catalytic reaction, and the catalytic activity of the catalyst is enhanced. The preparation method is simple, has low cost, is easy to regulate and control the proportion of the composite material, and is a novel preparation method of the perovskite type composite catalyst.
Description
Technical Field
The invention relates to the technical field of electrocatalysis, in particular to a perovskite type composite catalyst and a preparation method and application thereof.
Background
With the continuous development of social economy, the consumption of chemical energy is increasing day by day, so that fossil energy is gradually exhausted, and the carbon emission is continuously increased, so that the environmental problems of global warming and the like are caused. To solve these problems, the development and utilization of clean renewable energy sources are required to gradually reduce the dependence on fossil fuels. The hydrogen only generates water in the combustion process, and pollution is avoided, so that the hydrogen has a wide application prospect. In the related art, hydrogen is produced by electrolyzing water, and in the process of producing hydrogen by electrolyzing water, an oxygen evolution reaction and an oxygen reduction reaction are two key processes. However, because of the kinetic limitation, the spontaneous reaction process is very slow, so we need to find a high-efficiency catalyst to accelerate the reaction, so that the reaction can be carried out faster, and the hydrogen yield is higher.
The perovskite oxide belongs to non-noble metal oxide and has a chemical formula of ABO3+δWhere the a element is typically an element of the second main group, a lanthanide, or a multi-element mixture of the two; the B element is one or more transition metal elements, but the perovskite type oxide prepared in the related art has low catalytic activity and catalytic efficiency.
In view of the above, it is necessary to develop a perovskite-type composite catalyst which has high catalytic activity.
Disclosure of Invention
In order to solve the problems in the prior art, the invention provides a perovskite type composite catalyst which has high catalytic activity.
The invention also provides a preparation method of the catalyst.
The invention also provides the application of the catalyst in preparing oxygen evolution electrocatalyst.
The invention also provides an oxygen evolution electrocatalyst which is prepared from the perovskite type composite catalyst.
The invention provides a perovskite type composite catalyst, which comprises a perovskite material, wherein nano metal particles are distributed on the surface of the perovskite material;
the perovskite material has the following chemical formula:
La0.9Co1-δFeδO6；
wherein, delta is more than 0 and less than 1;
the nano metal particles include at least one of nano cobalt particles and nano iron particles.
According to one technical scheme of the perovskite type composite catalyst, the perovskite type composite catalyst at least has the following beneficial effects:
according to the invention, the nano metal particles are formed on the surface of the perovskite material, so that a new active site is provided for catalytic reaction, and the catalytic activity of the catalyst is enhanced.
According to some embodiments of the present invention, the crystal plane distance of CoFe (200) in the perovskite-type composite catalyst is 0.141 nm.
According to some embodiments of the invention, the LaFeO in the perovskite-type composite catalyst3(121) Has a interplanar distance of 0.178 nm. According to some embodiments of the invention, the perovskite material has a chemical formula in which 0 < δ < 0.5.
According to some embodiments of the invention, the perovskite material has a chemical formula wherein 0.1. ltoreq. delta. ltoreq.0.4.
According to some embodiments of the invention, the perovskite material comprises La0.9Co0.8Fe0.2O6And La0.9Co0.9Fe0.1O6At least one of (1).
According to some embodiments of the invention, the perovskite material is La0.9Co0.8Fe0.2O6。
The second aspect of the present invention provides a method for preparing the above perovskite-type composite catalyst, comprising the steps of:
s1, adding the aluminum lanthanum alloy into an inorganic strong alkali solution for reaction and then annealing to prepare perovskite oxide;
s2, reducing the perovskite oxide prepared in the step S1 to obtain the perovskite type composite catalyst;
the aluminum-lanthanum alloy in the step S1 comprises the following preparation raw materials: aluminum, lanthanum, cobalt and iron;
the temperature of the annealing treatment is 300-600 ℃.
According to at least one embodiment of the present invention, the following advantageous effects are provided:
the method prepares the La by dissolving and dealloying the inorganic strong base (dissolving the metallic aluminum by the inorganic strong base solution)0.9Co1-δFeδO6And the preparation process is simple, the component ratio is easy to control, and the method can be used for industrial mass production.
According to some embodiments of the invention, the aluminum in the aluminum lanthanum alloy in step S1 is 80% to 90% by mass.
According to some embodiments of the invention, the aluminum in the aluminum lanthanum alloy in step S1 is 85% to 90% by mass.
According to some embodiments of the invention, the aluminum-lanthanum alloy in step S1 has an aluminum mass fraction of 88.4%.
By controlling the mass fraction of Al, precipitates, salts and gases are generated in the subsequent process and the reaction of inorganic strong base, so that the purity of the catalyst prepared by the final reaction is improved.
According to some embodiments of the invention, the molar ratio of lanthanum, cobalt and iron in the aluminum lanthanum alloy is 9:1 to 2:8 to 9.
According to some embodiments of the invention, the aluminum lanthanum alloy has a lanthanum, cobalt, and iron molar ratio of 9:2: 8.
According to some embodiments of the present invention, the method for preparing the al-la alloy in step S1 includes the following steps:
adding the lanthanum, cobalt and iron into molten aluminum to prepare an alloy block; and heating and melting the alloy block, and then throwing to obtain the alloy.
According to some embodiments of the present invention, the method for preparing the al-la alloy in step S1 includes the following steps:
smelting aluminum, lanthanum, cobalt and iron in vacuum to prepare an alloy block; and then the alloy block is subjected to melt spinning treatment at 800-900 ℃ to obtain the alloy.
According to some embodiments of the invention, the vacuum is < 6 × 10-3Pa。
According to some embodiments of the invention, the smelting comprises the steps of: firstly, melting aluminum into a molten state, and stopping heating for 1-2 s; heating for 3-5 s again;
then melting lanthanum, cobalt and iron into the molten aluminum, and stopping heating for 1-2 s; heating for 3-5 s again; and cooling to obtain an alloy block.
The alloy is completely melted and uniformly melted through the smelting process.
According to some embodiments of the invention, the quartz tube used for the melt spinning is a quartz tube with a small hole at the bottom.
According to some embodiments of the invention, the bottom-holed quartz tube has a length of 300mm to 500 mm.
According to some embodiments of the invention, the quartz tube with the small holes at the bottom has a tube diameter of 10mm to 20 mm.
According to some embodiments of the invention, the quartz tube with the bottom hole has a hole diameter of 0.5mm to 1.5 mm.
According to some embodiments of the invention, the temperature of the reaction in step S1 is 60 ℃ to 90 ℃.
According to some embodiments of the invention, the reaction time in step S1 is 1h to 5 h.
According to some embodiments of the invention, the inorganic strong base solution in step S1 includes at least one of a sodium hydroxide solution, a potassium hydroxide solution, a cesium hydroxide solution, and a barium hydroxide solution.
According to some embodiments of the invention, the inorganic strong base solution comprises 5% to 20% by weight of inorganic strong base.
According to some embodiments of the invention, the reaction is dried in step S1.
According to some embodiments of the invention, the drying comprises vacuum drying.
According to some embodiments of the invention, the temperature of the drying is 60 ℃ to 80 ℃.
According to some embodiments of the invention, the annealing is performed for a time period of 2h to 5 h.
According to some embodiments of the invention, the temperature of the reduction in step S2 is 800 ℃ to 1100 ℃.
The temperature is within the molding temperature range of the material, if the temperature is too low, the material reaction is insufficient, and if the temperature is too high, the internal structure of the material is damaged, so that the material fails.
According to some embodiments of the invention, the time for the reduction in step S2 is 2h to 5 h.
According to some embodiments of the invention, the atmosphere of the reduction in step S2 is hydrogen and an inert gas.
According to some embodiments of the invention, the volume fraction of the hydrogen gas in the atmosphere reduced in step S2 is between 3% and 5%.
According to some embodiments of the invention, the volume fraction of the hydrogen gas in the atmosphere reduced in step S2 is 4%.
According to some embodiments of the invention, the inert gas comprises at least one of nitrogen, helium, argon, neon and krypton.
According to some embodiments of the invention, 1h of mixed gas is introduced before the reduction in step S2.
According to some embodiments of the invention, the gas mixture is the same as the reducing atmosphere.
The preparation method is simple, has low cost, is easy to regulate and control the proportion of the composite material, and is a novel preparation method of the perovskite type composite catalyst.
In a third aspect, the invention provides the use of the above-described perovskite-type composite catalyst in the preparation of an oxygen evolution electrocatalyst.
The fourth aspect of the invention provides an oxygen evolution electrocatalyst prepared from the perovskite type composite catalyst.
Drawings
Fig. 1 is an XRD spectrum of the perovskite type composite catalyst prepared in example 1 and example 2 of the present invention.
Fig. 2 is an XRD spectrum of the porous perovskite oxide composite material prepared in example 1 and example 2 of the present invention.
FIG. 3 is an SEM image of the porous perovskite oxide composite material and the perovskite-type composite catalyst prepared in examples 1 to 2 of the present invention.
FIG. 4 is a linear voltammogram of the porous perovskite oxide composite material and the perovskite-type composite catalyst in examples 1 to 2 of the present invention.
FIG. 5 is an AC impedance spectrum of the porous perovskite oxide composite material and the perovskite-type composite catalyst in examples 1 to 2 of the present invention.
Detailed Description
The concept and technical effects of the present invention will be clearly and completely described below in conjunction with the embodiments to fully understand the objects, features and effects of the present invention. It is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments, and those skilled in the art can obtain other embodiments without inventive effort based on the embodiments of the present invention, and all embodiments are within the protection scope of the present invention.
In the description of the present invention, reference to the description of the terms "one embodiment," "some embodiments," "an illustrative embodiment," "an example," "a specific example," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.
Specific examples of the present invention are described in detail below.
Example 1
The embodiment is a preparation method of a perovskite type composite catalyst, which comprises the following steps:
s1, according to atomic percentage: 88.4 percent of aluminum and 11.6 percent of lanthanum, cobalt and iron (the molar ratio of the lanthanum, the cobalt and the iron is controlled to be 9:2:8), and weighing a pure metal material;
s2, putting the weighed aluminum, lanthanum, cobalt and iron into a quartz tube, then putting the quartz tube filled with the metal raw materials into a vacuum induction furnace coil, vacuumizing until the vacuum degree is less than 6 multiplied by 10-3Pa, switching on a switch of a smelting furnace, and stopping heating for 1s after the aluminum is molten into a molten state; then heating for 3 seconds again, and stopping heating for 1 second after lanthanum, cobalt and iron are melted into the aluminum molten metal; and then heating for 3 seconds again to completely melt the alloy uniformly. Taking out the alloy ingot after cooling, polishing the surface of the alloy ingot, and cutting the alloy ingot into alloy blocks for melt spinning;
s3, taking a quartz tube with the length of 400mm, the diameter of 10mm and the diameter of a small hole at the bottom of 0.9mm, putting the alloy block obtained in the step S2 into the quartz tube, and heating and remelting a sample in a vacuum high-frequency induction furnace; when the temperature of the melt reaches 800 ℃, argon is blown in rapidly to carry out melt spinning, and the melt spinning is carried out under the protection of argon; obtaining an alloy strip;
s4, performing dealloying treatment on the alloy strip obtained in the step S3 in a sodium hydroxide solution with the mass fraction of 20% to obtain dealloyed material; wherein the treatment temperature is 60 ℃, and the reaction time is 2 h;
and then repeatedly washing the dealloying material for 3 times by using ultrapure water and alcohol, drying the dealloying material in a vacuum drying oven at 60 ℃, and annealing the dealloying material for 2 hours at 300 ℃ to obtain the porous perovskite oxide composite material.
S5, putting the porous perovskite oxide composite material obtained in the step S4 into a tube furnace, introducing nitrogen-hydrogen mixed gas for 1 hour (the volume fraction of hydrogen is 4%) at the low temperature of 60 ℃, then heating to 800 ℃, keeping the temperature for 2 hours, continuously keeping the input of the nitrogen-hydrogen mixed gas, and finally naturally cooling. And after obtaining the product, fully grinding the product for half an hour to obtain the perovskite type composite catalyst.
Example 2
The embodiment is a preparation method of a perovskite type composite catalyst, which comprises the following steps:
s1, according to atomic percentage: 88.4 percent of aluminum and 11.6 percent of lanthanum, cobalt and iron (the molar ratio of the lanthanum, the cobalt and the iron is controlled to be 9:1:9), and weighing a pure metal material;
s2, putting the weighed aluminum, lanthanum, cobalt and iron into a quartz tube, then putting the quartz tube filled with the metal raw materials into a vacuum induction furnace coil, vacuumizing until the vacuum degree is less than 6 multiplied by 10-3Pa, switching on a switch of a smelting furnace, and stopping heating for 2s after the aluminum is molten into a molten state; then heating for 4 seconds again, and stopping heating for 2 seconds after the lanthanum, the cobalt and the iron are melted into the aluminum molten metal; then heating for 4s again to completely melt the alloy uniformly; taking out the alloy ingot after cooling, polishing the surface of the alloy ingot, and cutting the alloy ingot into alloy blocks for melt spinning;
s3, taking a quartz tube with the length of 300mm, the diameter of 15mm and the diameter of a small hole at the bottom of 1.0mm, putting the small alloy obtained in the step S2 into the quartz tube, and heating and remelting a sample in a vacuum high-frequency induction furnace; when the temperature of the melt reaches 800 ℃, argon is blown in rapidly to carry out melt spinning, and the melt spinning is carried out under the protection of argon;
s4, performing dealloying treatment on the alloy strip obtained by the melt spinning in 20 wt.% of sodium hydroxide solution, wherein the treatment temperature is 70 ℃, and the reaction time is 3 hours; obtaining a dealloying material;
and then repeatedly washing the dealloying material for 3 times by using ultrapure water and alcohol, drying the dealloying material in a vacuum drying oven at 70 ℃, and annealing the dealloying material for 3 hours at 400 ℃ to obtain the porous perovskite oxide composite material.
S5, putting the porous perovskite oxide composite material prepared in the step S4 into a tube furnace, introducing nitrogen-hydrogen mixed gas (the volume fraction of hydrogen is 4%) for 1 hour at the low temperature of 60 ℃, then heating to 900 ℃, preserving heat for 3 hours, continuously keeping the input of the nitrogen-hydrogen mixed gas, and finally naturally cooling. And after obtaining the product, fully grinding the product for half an hour to obtain the perovskite type composite catalyst.
Example 3
The embodiment is a preparation method of a perovskite type composite catalyst, which comprises the following steps:
s1, according to atomic percentage: 88.4 percent of aluminum and 11.6 percent of lanthanum and iron (1:1), and weighing pure metal materials;
s2, putting the weighed aluminum, lanthanum, cobalt and iron into a quartz tube, then putting the quartz tube filled with the metal raw materials into a vacuum induction furnace coil, vacuumizing until the vacuum degree is less than 6 multiplied by 10-3Pa, switching on a switch of a smelting furnace, and stopping heating for 2s after the aluminum is molten into a molten state; then heating for 5 seconds again, and stopping heating for 2 seconds after the lanthanum, the cobalt and the iron are melted into the aluminum molten metal; and then heating for 5 seconds again to completely melt the alloy uniformly. Taking out the alloy ingot after cooling, polishing the surface of the alloy ingot, and cutting the alloy ingot into alloy blocks for melt spinning;
s3, taking a quartz tube with the length of 500mm, the diameter of 20mm and the diameter of a small hole at the bottom of 1.5mm, putting the alloy block obtained in the step S2 into the quartz tube, and heating and remelting a sample in a vacuum high-frequency induction furnace; when the temperature of the melt reaches 800 ℃, argon is blown in rapidly to carry out melt spinning, and the melt spinning is carried out under the protection of argon;
s4, performing dealloying treatment on the alloy strip obtained by the melt spinning in 20 wt.% of sodium hydroxide solution to obtain dealloyed material; wherein the treatment temperature is 90 ℃, and the reaction time is 5 h;
and then repeatedly washing the dealloying material for 3 times by using ultrapure water and alcohol, drying the dealloying material in a vacuum drying oven at the temperature of 80 ℃, and annealing the dealloying material for 5 hours at the temperature of 600 ℃ to obtain the porous perovskite oxide composite material.
S5, placing the porous perovskite oxide composite material into a tube furnace, introducing nitrogen-hydrogen mixed gas (the volume fraction of hydrogen is 4%) for one hour at the low temperature of 60 ℃, then heating to 1100 ℃, preserving heat for 5 hours, meanwhile, continuously keeping the input of the nitrogen-hydrogen mixed gas, and finally naturally cooling. And after obtaining the product, fully grinding the product for half an hour to obtain the perovskite type composite catalyst.
Test example
The perovskite type composite catalyst prepared in the embodiments 1-3 of the invention and carbon powder are mixed according to the mass ratio of 1:1, adding 500 mu L of Nafion diluted solution (the Nafion diluted solution is prepared by absolute ethyl alcohol with the volume fraction of 95 percent and Nafion solution with the volume fraction of 5 percent in a volume ratio of 9: 1) and 1500 mu L of isopropanol, and carrying out ultrasonic treatment in an ultrasonic instrument for 50min to obtain the ink solution of the electrode. The electrode ink solution was coated (coating amount was 30. mu.L, 10. mu.L each time, three drops) on a glassy carbon electrode, and naturally volatilized to prepare a glassy carbon electrode.
The electrochemical performance test mode of the invention is a three-electrode system, wherein the working electrode is a wave carbon electrode, the reference electrode is a saturated Hg/HgO electrode (vs. NHE 0.098V), the counter electrode is a carbon rod, a chemical workstation (SP240) is used for carrying out electrochemical test, oxygen is firstly introduced for 30 minutes before the test, the test is carried out in a 0.1mol/L KOH solution saturated by oxygen, when the OER electrochemical performance test is carried out, a cyclic voltammetry Curve (CV) is firstly scanned, the scanning interval is 0-1V vs. Hg/HgO, and the scanning rate is 50 mV/s; and performing linear sweep voltammetry, wherein the sweep interval is 0-1V vs. Hg/HgO, and the sweep rate is 5 mV/s.
The XRD patterns of the perovskite type composite catalysts prepared in the examples 1 and 2 of the present invention are shown in figure 1, and the XRD patterns of the porous perovskite oxide composite materials prepared in the examples 1 and 2 of the present invention are shown in figure 2 (the standard PDF card of LaFeO3 in figures 1 and 2 is PDF # 37-1493). From a comparison of fig. 1 and 2, it can be seen that: first, typical diffraction peaks for LCFO before reduction (porous perovskite oxide composites made in examples 1 and 2) and LaFeO3Standard diffraction peak of (PDF #37-1493 LaFeO)3) The match was good and there were no unwanted diffraction peaks, indicating that no metal cations were precipitated from the sample before reduction. Typical diffraction peaks of LCFO after the second reduction (perovskite-type composite catalysts prepared in examples 1 and 2) and LaFeO3Standard diffraction peak of (PDF #37-1493 LaFeO)3) The match was good and there were no extra diffraction peaks, indicating that at high temperature the hydroxide decomposed to oxygenThe compound, Co ion is successfully doped into LaFeO3In the (LFO) crystal lattice, LFCO has a good crystallinity, and since the diffraction peak is smooth, the crystal structure is good and stable. LFCO-1/9 (perovskite type composite catalyst prepared in example 2) and LCFO-2/8 (perovskite type composite catalyst prepared in example 1) reduced under nitrogen-hydrogen mixed gas with volume concentration of 4% separate the diffraction peak of Co-Fe of metal nanoparticles from the diffraction peak of LCFO at 44.8 degrees in an XRD pattern, and a small diffraction peak appears, while the diffraction peak of LCFO-2/8 is the highest and the diffraction peak of LFCO-1/9 is the second highest, which shows that the more Co-Fe mixed phase is separated with the increase of Co content. The diffraction peaks occur because of lattice expansion caused by the protrusion of the metal cations at the B-site of the perovskite oxide and the shift in the fundamental phase due to the synergistic effect of cobalt in the perovskite oxide.
SEM images of the porous perovskite oxide composite material and the perovskite-type composite catalyst prepared in examples 1 to 2 of the present invention are shown in fig. 3 (in fig. 3, the upper left corner (a) corresponds to the porous perovskite oxide composite material prepared in step S4 of example 2, the upper right corner (b) corresponds to the porous perovskite oxide composite material prepared in step S4 of example 1, the lower left corner (c) corresponds to the perovskite-type composite catalyst prepared in step S5 of example 2, and the lower right corner (d) corresponds to the perovskite-type composite catalyst prepared in step S5 of example 1). From fig. 3 it can be seen that: according to the invention, through the reduction process of step S5, part of metal in the porous perovskite oxide composite material is finally reduced, so that the surface of the prepared perovskite type composite catalyst contains CoFe alloy particles. As can be seen from the figure, LCFO-1/9 (porous perovskite oxide composite and perovskite-type composite catalyst made in example 2) is in the form of loose, bulk particles with a somewhat lower degree of aggregation; LCFO-2/8 (porous perovskite oxide composite and perovskite-type composite catalyst prepared in example 1) was in the form of platelets and had a high degree of bulk. The surface loosening degree of the perovskite oxide is increased along with the increase of the content of Co and the reduction of the content of Fe, and the synergistic effect of Co and metal ions in the perovskite oxide is shown. The surface of the reduced perovskite oxide has more and smooth pores than the surface of the calcined perovskite oxide, and as the amount of Co increases, the amount of Fe decreases, the metal particles on the surface of the perovskite oxide are more dense, and the pore shape appears more frequently. The perovskite oxide is produced in a porous state due to the preparation mode of dealloying, so that the CoFe alloy is produced on the surface of the perovskite oxide.
The prepared porous perovskite oxide composite material and perovskite type composite catalyst OER catalytic performance are evaluated through a polarization curve measured by a linear voltammetry (LSV). All potential values were referenced to the reversible electrode (RHE) and IR correction. LSV curves were tested on Cyclic Voltammetry (CV) scan activated samples (fig. 4). LCFO-1/9 (example 2) is lower than LCFO-2/8 (example 1) in terms of initial potential and current density, both in porous perovskite oxide composite and in perovskite-type composite catalysts (i.e. before and after reduction of the porous perovskite oxide composite). However, it is clear that the perovskite oxide after reduction is more excellent than that before reduction, while LCFO-2/8-800-2h (the perovskite-type composite catalyst prepared in example 1) has a smaller initial potential and a larger current density.
The catalytic kinetics of the above samples were studied using EIS, the Nyquist plot achieved under the same conditions as the LSV test, and the EIS Nyquist plot (FIG. 5) shows that the half-circle radius of LCFO-2/8-800-2h (the perovskite-type composite catalyst prepared in example 1) is the smallest in all samples, indicating the fastest charge transfer rate of LCFO-2/8-800-2h (the perovskite-type composite catalyst prepared in example 1). The electrochemical results above show that LCFO-2/8-800-2h (perovskite-type composite catalyst prepared in example 1) has the best OER activity. Improving OER performance is also related to Co doping and changes in the surface state of the O species. The semi-circle radius of the reduced perovskite oxide is larger than that of the perovskite oxide before reduction, which shows that the precipitation of the CoFe alloy and the obvious influence of a porous structure on the surface.
In conclusion, the La is prepared by the dealloying method0.9Co1-δFeδO6La appears in different proportions0.9Co0.1Fe0.9O6、La0.9Co0.2Fe0.8O6Two products, and the preparation process is simple, the component ratio is easy to control, and the method can be used for industrial mass production; book (I)The invention separates out nano metal particles on the surface of the porous perovskite by reduction to form a new material structure, and opens up a new way for researching the electrocatalytic performance of the perovskite oxide.
While the embodiments of the present invention have been described in detail with reference to the specific embodiments, the present invention is not limited to the embodiments, and various changes can be made without departing from the spirit of the present invention within the knowledge of those skilled in the art. Furthermore, the embodiments of the present invention and the features of the embodiments may be combined with each other without conflict.
Claims (10)
1. A perovskite-type composite catalyst characterized in that: the perovskite type composite catalyst comprises a perovskite material, and nano metal particles are distributed on the surface of the perovskite material;
the perovskite material has the following chemical formula:
La0.9Co1-δFeδO6；
wherein, delta is more than 0 and less than 1;
the nano metal particles include at least one of nano cobalt particles and nano iron particles.
2. The perovskite-type composite catalyst according to claim 1, characterized in that: the chemical formula of the perovskite material is that delta is more than 0 and less than 0.5.
3. A method for producing the perovskite-type composite catalyst as set forth in claim 1 or 2, characterized in that: the method comprises the following steps:
s1, adding the aluminum lanthanum alloy into an inorganic strong alkali solution for reaction and then annealing to prepare perovskite oxide;
s2, reducing the perovskite oxide prepared in the step S1 to obtain the perovskite type composite catalyst;
the aluminum-lanthanum alloy in the step S1 comprises the following preparation raw materials: metallic aluminum, metallic lanthanum, metallic cobalt and metallic iron;
the temperature of the annealing treatment is 300-600 ℃.
4. The method of claim 3, wherein: in the step S1, the mass fraction of aluminum in the aluminum lanthanum alloy is 80-90%.
5. The method of claim 3, wherein: the preparation method of the aluminum-lanthanum alloy in the step S1 comprises the following steps:
adding the lanthanum, cobalt and iron into molten aluminum to prepare an alloy block; and heating and melting the alloy block, and then throwing to obtain the alloy.
6. The method of claim 3, wherein: the reaction temperature in step S1 is 60 ℃ to 90 ℃.
7. The method of claim 3, wherein: the inorganic strong alkali solution in the step S1 includes at least one of a sodium hydroxide solution, a potassium hydroxide solution, a cesium hydroxide solution, and a barium hydroxide solution; preferably, the mass fraction of the inorganic strong base in the inorganic strong base solution is 5-20%.
8. The method of claim 3, wherein: the reduction temperature in the step S2 is 800-1100 ℃; preferably, the time for the reduction in step S2 is 2h to 5 h.
9. The method of claim 3, wherein: the atmosphere of the reduction in step S2 is hydrogen and an inert gas.
10. An oxygen evolution electrocatalyst, characterized by: the preparation raw material comprises the perovskite-type composite catalyst as claimed in claim 1 or 2.
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| JP2007084390A (en) * | 2005-09-26 | 2007-04-05 | Toyota Motor Corp | Perovskite type compound oxide particle and its producing method |
| US20170088433A1 (en) * | 2014-03-13 | 2017-03-30 | Japan Science And Technology Agency | Ammonia synthesis catalyst and ammonia synthesis method |
| US20190046961A1 (en) * | 2016-02-24 | 2019-02-14 | University College Cardiff Consultants Ltd. | Supported catalyst |
| CN113385185A (en) * | 2021-07-02 | 2021-09-14 | 上海应用技术大学 | High-activity and selective perovskite type photo-thermal catalyst and preparation method and application thereof |
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| JP2007084390A (en) * | 2005-09-26 | 2007-04-05 | Toyota Motor Corp | Perovskite type compound oxide particle and its producing method |
| US20170088433A1 (en) * | 2014-03-13 | 2017-03-30 | Japan Science And Technology Agency | Ammonia synthesis catalyst and ammonia synthesis method |
| US20190046961A1 (en) * | 2016-02-24 | 2019-02-14 | University College Cardiff Consultants Ltd. | Supported catalyst |
| CN113385185A (en) * | 2021-07-02 | 2021-09-14 | 上海应用技术大学 | High-activity and selective perovskite type photo-thermal catalyst and preparation method and application thereof |
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