阅读说明：本技术 改性钙钛矿型催化剂及其制备方法和应用 (Modified perovskite type catalyst and preparation method and application thereof ) 是由 陈浩 赵杰 于丽丽 王勇 李浩然 陈志荣 黄国东 徐显会 王玉岗 刘洋 于 2020-12-10 设计创作，主要内容包括：本发明涉及一种改性钙钛矿型催化剂,包括载体、M元素、贵金属元素以及非金属元素,载体的材料为LaVO-3,M元素包括Ce、Nb、Zr中的至少一种,非金属元素包括C和/或S,其中,M元素负载于载体上和/或进入载体的晶体结构中取代部分La元素,贵金属元素负载于载体上和/或进入载体的晶体结构中取代部分V元素,非金属元素负载于载体上和/或进入载体的晶体结构中取代部分O元素。本发明还涉及一种改性钙钛矿型催化剂的制备方法及其应用。本发明的改性钙钛矿型催化剂在用作催化湿式氧化降解含盐废水的催化剂时,能够有效促进有机物的分解,同时,改性钙钛矿型催化剂的表面不易结焦,可以在间歇条件下循环套用,使用寿命长。(The invention relates to a modified perovskite catalyst, which comprises a carrier, an M element, a noble metal element and a nonmetal element, wherein the carrier is made of LaVO 3 M element comprises at least one of Ce, Nb and Zr, and nonmetal element comprises C and/or S, wherein the M element is loaded on the carrier and/or enters the crystal structure of the carrier to replace part of La element and precious metal elementThe element is loaded on the carrier and/or enters the crystal structure of the carrier to replace partial V element, and the non-metal element is loaded on the carrier and/or enters the crystal structure of the carrier to replace partial O element. The invention also relates to a preparation method and application of the modified perovskite catalyst. When the modified perovskite type catalyst is used as a catalyst for catalyzing wet oxidation degradation of salt-containing wastewater, the decomposition of organic matters can be effectively promoted, and meanwhile, the surface of the modified perovskite type catalyst is not easy to coke, can be recycled under intermittent conditions, and has long service life.)

1. The modified perovskite catalyst is characterized by comprising a carrier, an M element, a noble metal element and a nonmetal element, wherein the carrier is made of LaVO₃The M element comprises at least one of Ce, Nb and Zr, and the nonmetal element comprises C and/or S, wherein the M element is loaded on the carrier and/or enters the crystal structure of the carrier to replace part of La element, the noble metal element is loaded on the carrier and/or enters the crystal structure of the carrier to replace part of V element, and the nonmetal element is loaded on the carrier and/or enters the crystal structure of the carrier to replace part of O element.

2. The modified perovskite catalyst of claim 1, wherein the mass of the M element is 1% to 10% of the mass of the support;

and/or the mass of the noble metal element is 0.1-4% of the mass of the carrier;

and/or the mass of the non-metal element is 1-16% of the mass of the carrier.

3. The modified perovskite catalyst of claim 1, wherein the non-metallic elements comprise C and S.

4. The modified perovskite catalyst according to claim 3, wherein the content by mass of the C element in the modified perovskite catalyst is 0.6 to 8%, and the content by mass of the S element in the modified perovskite catalyst is 0.6 to 8%.

5. The modified perovskite catalyst of claim 1, wherein the noble metal element comprises at least one of Ru, Pt, Pd.

6. A process for the preparation of a modified perovskite catalyst as claimed in any one of claims 1 to 5, comprising:

providing LaVO₃As a support, subjecting the support to a first calcination;

soaking the carrier subjected to the first calcination in a first solution, and performing first drying and second calcination to obtain a first intermediate product, wherein the first solution comprises a precursor of an M element, a precursor of a noble metal element, a complexing agent and a solvent; and

and soaking the first intermediate product in a second solution, and performing second drying and third calcining to obtain the modified perovskite catalyst, wherein the second solution comprises a precursor of a non-metal element and a solvent, and the precursor of the non-metal element comprises a precursor of a C element and/or a precursor of an S element.

7. The method for producing a modified perovskite catalyst according to claim 6, wherein the mass percentage of the precursor of the M element in the first solution is 4 to 18%, the mass percentage of the precursor of the noble metal element in the first solution is 2 to 14%, and the pH of the first solution is 2 to 4.

8. The method for producing a modified perovskite catalyst according to claim 6, wherein the mass percentage of the precursor of the non-metallic element in the second solution is 2% to 15%.

9. The method for producing a modified perovskite catalyst according to claim 8, wherein when the precursor of the non-metal element includes a precursor of a C element and a precursor of an S element, the mass percentage of the precursor of the C element in the second solution is 0.8% to 8%, and the mass percentage of the precursor of the S element in the second solution is 1% to 7%.

10. The process for preparing a modified perovskite catalyst according to claim 6, wherein the first calcination is carried out at a temperature of 500 ℃ to 900 ℃ for 2h to 6h at a temperature rise rate of 1 ℃/min to 5 ℃/min.

11. The method for preparing a modified perovskite catalyst according to claim 6, wherein the temperature of the carrier is 300 ℃ to 400 ℃ when the carrier subjected to the first calcination is immersed in the first solution, the solid-to-liquid ratio of the carrier to the first solution is 1g:5mL to 1g:10mL, and the immersion time is 5h to 20 h.

12. The process for preparing a modified perovskite catalyst according to claim 6, wherein the second calcination is carried out at a temperature of 400 ℃ to 500 ℃ for 2h to 6h at a temperature rise rate of 1 ℃/min to 5 ℃/min.

13. The method for producing a modified perovskite catalyst according to claim 6, wherein the temperature of the first intermediate product is 200 ℃ to 250 ℃ when the first intermediate product is immersed in the second solution, the solid-to-liquid ratio of the support to the second solution is 1g:5mL to 1g:10mL based on the support and the second solution, and the immersion time is 5h to 15 h.

14. The process for preparing a modified perovskite catalyst according to claim 6, wherein the third calcination is carried out at a temperature of 300 ℃ to 500 ℃ for 2h to 6h at a temperature rise rate of 1 ℃/min to 5 ℃/min in a nitrogen and/or inert atmosphere.

15. Use of a modified perovskite catalyst as defined in any one of claims 1 to 5 as a catalyst for the catalytic wet oxidative degradation of salt-containing wastewater.

16. Use of a modified perovskite catalyst as claimed in claim 15 wherein the salt-containing wastewater comprises aniline salt-containing wastewater.

Technical Field

The invention relates to the technical field of catalytic wet oxidation, in particular to a modified perovskite catalyst and a preparation method and application thereof.

Background

The catalytic wet oxidation technology (CWAO) is an effective technology for treating high-concentration, toxic, harmful and difficultly biodegradable wastewater developed in the 80 th 20 th century, and the main principle of the technology is as follows:under the action of the catalyst, organic matter molecules, ammonia nitrogen, sulfide and the like in the wastewater are efficiently oxidized into CO under the atmosphere of lower temperature, pressure, oxygen or air₂、SO₂、NO₂And the purpose of purifying the waste water is achieved.

Catalysts used in CWAO technology are classified into homogeneous catalysts and heterogeneous catalysts. Most of the homogeneous catalysts are soluble iron salts, copper salts, nickel salts and the like, and although the catalysts are low in price and high in efficiency, the catalysts are difficult to separate in the later period and easily cause secondary pollution. Compared with homogeneous catalysts, heterogeneous catalysts have the advantages of simple separation, reusability and the like, so that the heterogeneous catalysts become a current research hotspot, but the problems of low dispersity of active components of the heterogeneous catalysts, easy loss, easy coking of the surfaces of the catalysts and the like are not solved.

In this regard, patent CN102451713A describes a catalyst prepared by loading Cu-Zn-Pt on activated carbon by impregnation method for treating phenol-containing wastewater, however, the catalyst prepared by loading transition metal and noble metal on carrier is often accompanied by transition metal loss during the use process, which not only causes the performance of the catalyst to be reduced and the service life to be shortened, but also causes secondary pollution.

Patent CN102101053A describes a process for supporting metal carbonyls on gamma-Al₂O₃Or TiO₂The catalyst prepared in the above is used for treating high-concentration organic wastewater, however, the problem of coking and loss of the catalyst is solved by reducing the loading amount of the active component, if the content of organic matters in the wastewater is high, the treatment effect is poor, or the treatment effect needs to be achieved by prolonging the treatment time, so that the wastewater treatment amount is reduced, and the operation cost is increased.

Patent CN1531997A describes a method for preparing a perovskite composite oxide supported palladium catalyst by using a solid phase crystallization method, wherein although metal palladium can be uniformly dispersed on the surface of the catalyst, the noble metal particles are dispersed on the surface of the catalyst in the solid phase crystallization process and are easily affected by factors such as reduction temperature and gas atmosphere; in addition, the Co element in the catalyst is easy to run off in use, which not only causes secondary pollution, but also influences the phase structure of the catalyst.

Disclosure of Invention

In view of the above, there is a need to provide a modified perovskite catalyst, and a preparation method and application thereof.

A modified perovskite catalyst comprises a carrier, an M element, a noble metal element and a nonmetal element, wherein the carrier is made of LaVO₃The M element comprises at least one of Ce, Nb and Zr, and the nonmetal element comprises C and/or S, wherein the M element is loaded on the carrier and/or enters the crystal structure of the carrier to replace part of La element, the noble metal element is loaded on the carrier and/or enters the crystal structure of the carrier to replace part of V element, and the nonmetal element is loaded on the carrier and/or enters the crystal structure of the carrier to replace part of O element.

In one embodiment, the mass of the M element is 1-10% of the mass of the carrier;

and/or the mass of the noble metal element is 0.1-4% of the mass of the carrier;

and/or the mass of the non-metal element is 1-16% of the mass of the carrier.

In one embodiment, the non-metallic elements include C and S.

In one embodiment, the content of the C element in the modified perovskite catalyst is 0.6% to 8% by mass, and the content of the S element in the modified perovskite catalyst is 0.6% to 8% by mass.

In one embodiment, the noble metal element comprises at least one of Ru, Pt, Pd.

A method of preparing a modified perovskite catalyst as described above, comprising:

providing LaVO₃As a support, subjecting the support to a first calcination;

soaking the carrier subjected to the first calcination in a first solution, and performing first drying and second calcination to obtain a first intermediate product, wherein the first solution comprises a precursor of an M element, a precursor of a noble metal element, a complexing agent and a solvent; and

and soaking the first intermediate product in a second solution, and performing second drying and third calcining to obtain the modified perovskite catalyst, wherein the second solution comprises a precursor of a non-metal element and a solvent, and the precursor of the non-metal element comprises a precursor of a C element and/or a precursor of an S element.

In one embodiment, the mass percentage of the precursor of the M element in the first solution is 4% to 18%, the mass percentage of the precursor of the noble metal element in the first solution is 2% to 14%, and the pH of the first solution is 2 to 4.

In one embodiment, the precursor of the non-metal element is 2 to 15% by mass of the second solution.

In one embodiment, when the precursor of the non-metal element includes a precursor of a C element and a precursor of an S element, the mass percentage content of the precursor of the C element in the second solution is 0.8% to 8%, and the mass percentage content of the precursor of the S element in the second solution is 1% to 7%.

In one embodiment, the temperature of the first calcination is 500-900 ℃, the time is 2-6 h, and the temperature rise rate is 1-5 ℃/min.

In one embodiment, when the carrier after the first calcination is immersed in the first solution, the temperature of the carrier is 300-400 ℃, the solid-to-liquid ratio of the carrier to the first solution is 1g:5mL-1g:10mL, and the immersion time is 5-20 h.

In one embodiment, the temperature of the second calcination is 400-500 ℃, the time is 2-6 h, and the heating rate is 1-5 ℃/min.

In one embodiment, when the first intermediate product is immersed in the second solution, the temperature of the first intermediate product is 200-250 ℃, the solid-to-liquid ratio of the carrier to the second solution is 1g:5mL-1g:10mL, and the immersion time is 5-15 h.

In one embodiment, the third calcination is performed at 300-500 ℃ for 2-6 h at a temperature rise rate of 1-5 ℃/min in a nitrogen and/or inert atmosphere.

Use of a modified perovskite catalyst as described above as a catalyst for the catalytic wet oxidative degradation of salt-containing wastewater.

In one embodiment, the salt-containing wastewater comprises aniline salt-containing wastewater.

The modified perovskite catalyst has good electron transfer characteristic and is favorable for adsorbing oxygen to form O₂The free radicals are present to promote the formation of HO₂And the strongly oxidising species. Meanwhile, the Zeta potential value of the modified perovskite type catalyst under the acidic condition is higher than that of the unmodified perovskite type catalyst, so that the surface of the modified perovskite type catalyst can generate positive polarization, and small molecules and the like which are not completely decomposed are promoted to be adsorbed on the surface of the modified perovskite type catalyst for being decomposed again.

Therefore, the modified perovskite catalyst has more excellent catalytic effect, and meanwhile, as the active components M element, noble metal element and nonmetal element in the modified perovskite catalyst can be loaded on the surface of the carrier and can also enter the crystal structure of the carrier to replace La element, V element and O element in the carrier, the performance of the modified perovskite catalyst is more stable. When the modified perovskite catalyst is used as a catalyst for catalyzing wet oxidation degradation of salt-containing wastewater, the decomposition of organic matters can be effectively promoted, the surface of the modified perovskite catalyst is not easy to coke, the modified perovskite catalyst can be recycled under intermittent conditions, and the service life is long.

In addition, the modified perovskite catalyst is prepared by a hot dipping method, the process is simple, and meanwhile, active components of M element, noble metal element and non-metal element can be loaded on the surface of the carrier, and the M element, noble metal element and non-metal element can enter the crystal structure of the carrier to replace La element, V element and O element in the carrier, so that the modified perovskite catalyst with excellent performance can be obtained, the utilization rate of the active components is high, the consumption of the active components can be reduced, and the production cost is reduced. Therefore, the preparation method of the modified perovskite catalyst is suitable for industrial production.

Drawings

FIG. 1 is a Zeta potential graph of the modified perovskite catalysts obtained in example 3 and comparative example 1, wherein a is a Zeta potential curve of the modified perovskite catalyst of example 3 and b is a Zeta potential curve of the modified perovskite catalyst of comparative example 1.

Detailed Description

The modified perovskite catalyst provided by the invention, and the preparation method and application thereof will be further explained below.

The modified perovskite catalyst provided by the invention comprises a carrier, an M element, a noble metal element and a nonmetal element, wherein the carrier is made of LaVO₃The M element comprises at least one of Ce, Nb and Zr, and the nonmetal element comprises C and/or S, wherein the M element is loaded on the carrier and/or enters the crystal structure of the carrier to replace part of La element, the noble metal element is loaded on the carrier and/or enters the crystal structure of the carrier to replace part of V element, and the nonmetal element is loaded on the carrier and/or enters the crystal structure of the carrier to replace part of O element.

In order to provide better catalytic effect to the modified perovskite type catalyst, in one or more embodiments, the mass of the M element is 1-10% of the mass of the carrier, the mass of the noble metal element is 0.1-4% of the mass of the carrier, and the mass of the nonmetal element is 1-16% of the mass of the carrier.

When the M element enters the crystal structure of the carrier to replace part of the La element, the noble metal element enters the crystal structure of the carrier to replace part of the V element, and the non-metal element enters the carrierWhen partial O element is substituted in the crystal structure of the carrier, the molecular general formula of the carrier is La_αM_1-αN_1-βV_βO_θZ_3-θWherein N is a noble metal element, and Z is a non-metal element.

Further, in the molecular general formula, the range of α is preferably 0.05-0.2, the range of β is preferably 0.01-0.05, the range of θ is preferably 0.5-1.5, and the rest of M element, noble metal element and nonmetal element are loaded on the surface of the carrier.

In the modified perovskite catalyst, the valence state of the metal element M can be adjusted by doping the non-metal element C and/or S, so that the M in the catalyst^δ+1And M^δIs changed, and M^δ+1And M^δThe mutual conversion between the variable valence states ensures that the modified perovskite catalyst has good electron transfer characteristic and is beneficial to adsorbing oxygen to form O₂The free radicals are present to promote the formation of HO₂And the strongly oxidising species. Meanwhile, the V element has better acid and alkali resistance, particularly better sulfuric acid and hydrochloric acid resistance, and the valence state of the V element is more, and the change of the valence state can also cause the transfer of electrons, thereby being beneficial to adsorbing oxygen to form O₂The free radicals are present to promote the formation of HO₂And the strongly oxidising species. When the strong oxide species is used as a catalyst for catalyzing wet oxidation degradation of salt-containing wastewater, the strong oxide species can effectively promote decomposition of organic matters such as aniline and the like, and further is beneficial to improving the catalytic effect of the catalyst.

In addition, the Zeta potential value of the perovskite type catalyst doped with the nonmetallic elements C and/or S is higher than that of the unmodified perovskite type catalyst under an acidic condition, so that the surface of the modified perovskite type catalyst can generate a positive polarization effect, small molecules and the like which are not completely decomposed are promoted to be adsorbed on the surface of the modified perovskite type catalyst for secondary decomposition, and therefore small molecular organic matters can be fully decomposed without forming a complex with the modified perovskite type catalyst and accumulating on the surface to form coking.

Therefore, the modified perovskite catalyst has more excellent catalytic effect, and can effectively promote the decomposition of organic matters when being used as a catalyst for catalyzing wet oxidation degradation of salt-containing wastewater. Specifically, the TOC removal rate and the TN removal rate in the wastewater can be respectively kept above 85% and 80%, and meanwhile, the surface of the modified perovskite catalyst is not easy to coke, can be recycled under intermittent conditions, and is long in service life.

Meanwhile, the active components M element, noble metal element and nonmetal element in the modified perovskite catalyst can be loaded on the surface of the carrier and can also enter the crystal structure of the carrier to replace La element, V element and O element in the carrier, so that the performance of the modified perovskite catalyst is more stable.

In one or more embodiments, the non-metallic elements include C and S. Compared with the single element modified perovskite catalyst, the C and S composite modified perovskite catalyst can achieve better catalytic effect under the mild (weak acid condition) condition. Specifically, the TOC removal rate and the TN removal rate in the wastewater can be kept above 85%.

Further, when C and S are compositely modified, the mass percentage of the C element in the modified perovskite type catalyst is 0.6-8%, and the mass percentage of the S element in the modified perovskite type catalyst is 0.6-8%. Therefore, by adjusting the composite doping amount of C and S, the removal rate of TOC in the wastewater can be kept above 90 percent, even can reach above 98 percent, and the removal rate of TN in the wastewater can be kept above 90 percent, even can reach above 92 percent. Moreover, the surface of the perovskite catalyst is not easy to coke, more than 50 perovskite catalysts can be recycled under intermittent conditions, and the service life is long.

In one or more embodiments, the noble metal element includes at least one of Ru, Pt, Pd.

The invention also provides a preparation method of the modified perovskite catalyst, which comprises the following steps:

s1, providing LaVO₃As a support, subjecting the support to a first calcination;

s2, dipping the carrier after the first calcination in a first solution, and performing first drying and second calcination to obtain a first intermediate product, wherein the first solution comprises a precursor of an M element, a precursor of a noble metal element, a complexing agent and a solvent;

and S3, dipping the first intermediate product into a second solution, and carrying out secondary drying and tertiary calcination to obtain the modified perovskite catalyst, wherein the second solution comprises a precursor of a non-metal element and a solvent, and the precursor of the non-metal element comprises a precursor of a C element and/or a precursor of an S element.

In step S1, LaVO₃When the carrier is calcined for the first time, the first calcination is carried out in the air atmosphere, the temperature of the first calcination is 500-900 ℃, the time is 2-6 h, and the temperature rise rate is 1-5 ℃/min. Therefore, the crystal form of the carrier can be changed into an orthorhombic system through first calcination, and the V element at the B position and the O element form octahedral coordination, so that doping modification is facilitated.

In step S2, the mass percentage of the precursor of the M element in the first solution is 4% to 18%, and the mass percentage of the precursor of the noble metal element in the first solution is 2% to 14%. In order to make it easier to load the precursor of the noble metal element on the carrier, the pH of the first solution is preferably 2 to 4.

Specifically, a precursor containing an M element and a precursor containing a noble metal element may be dissolved in deionized water to obtain a salt solution containing the M element and the noble metal element, and then a complexing agent is added to obtain the first solution.

Wherein the precursor containing a noble metal element comprises Pt (NO)₃)₂、Pd(NO₃)₂、H₂PtCl₆·6H₂Salts containing a noble metal element such as O, and the M element-containing precursor includes Ce (NO)₃)₃·6H₂O、Zr(NO₃)₄·5H₂O、Nb(NO₃)₅·5H₂And nitrate containing M element such as O, wherein the complexing agent comprises at least one of citric acid and lactic acid.

In order to ensure the hot dipping effect, when the carrier after the first calcination is immersed in the first solution, the temperature of the carrier is 300-400 ℃, the solid-to-liquid ratio of the carrier to the first solution is 1g:5mL-1g:10mL, and the immersion time is 5-20 h. After the impregnation is finished, the temperature for the first drying is 80-150 ℃, and the time is 4-12 h.

And when the second calcination is carried out, the second calcination is carried out in the air atmosphere, the temperature of the second calcination is 400-500 ℃, the time is 2-6 h, and the temperature rise rate is 1-5 ℃/min, so that the precursor containing the M element and the precursor containing the noble metal element form chemical bonds with oxygen in crystal lattices and are limited in the crystal lattices or on the surfaces of the carriers. Wherein, the M element is loaded on the surface of the carrier or enters the crystal structure of the carrier to replace La of a part of A sites, and the noble metal is loaded on the surface of the carrier or enters the crystal structure of the carrier to replace V of a part of B sites.

In step S3, the mass percentage of the precursor of the non-metal element in the second solution is 2% to 15%, wherein when the precursor of the non-metal element includes a precursor of a C element and a precursor of an S element, the mass percentage of the precursor of the C element in the second solution is 0.8% to 8%, and the mass percentage of the precursor of the S element in the second solution is 1% to 7%.

Specifically, the precursor containing the C element and/or the precursor containing the S element may be dissolved in deionized water to obtain the second solution. The precursor containing the element C comprises carbonates such as sodium bicarbonate, sodium carbonate and potassium bicarbonate, and the precursor containing the element S comprises sulfates such as sodium sulfate, sodium bisulfate and sodium sulfite.

In order to prevent the precursor of the non-metallic element from being decomposed at high temperature, when the first intermediate product obtained through the second calcination is immersed in the second solution, the temperature of the first intermediate product is 200-250 ℃, the solid-to-liquid ratio of the carrier to the second solution is 1g:5mL-1g:10mL, and the immersion time is 5-15 h. After the impregnation is finished, the temperature for the second drying is 80-120 ℃, and the time is 4-12 h.

And during the third calcination, the temperature of the third calcination is 300-500 ℃, the time is 2-6 h, and the heating rate is 1 ℃/min-5 ℃/min, so that the precursor containing the C element and/or the precursor containing the S element is decomposed into the C element and/or the S element at high temperature, the C element and/or the S element enters the crystal structure of the carrier to replace part of the O element, or the C element and the S element form a chemical bond to produce O vacancies.

Specifically, the third calcination is performed in a nitrogen and/or inert atmosphere to ensure that the non-metallic elements are not oxidized.

The modified perovskite catalyst is prepared by a hot dipping method, the process is simple, and meanwhile, active components of M element, noble metal element and non-metal element can be loaded on the surface of the carrier, and the M element, noble metal element and non-metal element can enter the crystal structure of the carrier to replace La element, V element and O element in the carrier, so that the modified perovskite catalyst with excellent performance can be obtained, the utilization rate of the active components is high, the consumption of the active components can be reduced, and the production cost is reduced. Therefore, the preparation method of the modified perovskite catalyst is suitable for industrial production.

The invention also provides application of the modified perovskite type catalyst, which is used as a catalyst for catalyzing wet oxidation degradation of salt-containing wastewater.

In one or more embodiments, the salt-containing wastewater comprises aniline salt-containing wastewater.

In one or more embodiments, when the modified perovskite type catalyst is used for a catalyst for degrading salt-containing wastewater, the reaction conditions are 120-300 ℃, the oxygen partial pressure is 1.2-3.0 MPa, and the oxidant is one of oxygen or air.

HO formed by the modified perovskite catalyst when being used as a catalyst for catalyzing wet oxidation degradation of salt-containing wastewater₂The strong oxide species effectively promote the decomposition of organic substances such as anilines, and the small molecules and the like which are not completely decomposed are adsorbed on the surface of the modified perovskite catalyst and are decomposed again. Therefore, thisThe modified perovskite catalyst has more excellent catalytic effect when being used as a catalyst for catalyzing wet oxidation degradation of salt-containing wastewater, and meanwhile, the surface of the modified perovskite catalyst is not easy to coke, can be recycled under intermittent conditions and has long service life.

Hereinafter, the modified perovskite catalyst, the preparation method and the application thereof will be further described by the following specific examples.

Example 1

4.7864g of Pt (NO)₃)₂17.3688g of Ce (NO)₃)₃·6H₂Dissolving 500mL of ionized water by using O, and adding a proper amount of citric acid as a complexing agent to obtain a first solution with the pH value of 3. 82.3298g of sodium bicarbonate was dissolved in 700mL of deionized water to give a second solution.

Weighing 100g of LaVO₃And placing the perovskite composite oxide in a muffle furnace, and calcining for 4 hours at 650 ℃ in the atmosphere of air. When the temperature in the muffle furnace is reduced to 350 ℃, the calcined LaVO is added₃And dipping the perovskite composite oxide into the first solution while the perovskite composite oxide is hot, standing for 10h, taking out, drying in a drying oven at 110 ℃, then placing in a muffle furnace, and calcining at 450 ℃ for 4h to obtain a first intermediate product loaded with Pt and Ce.

And when the temperature in the muffle furnace is reduced to 200 ℃, soaking the first intermediate product in the second solution, standing for 10h, taking out, drying in an oven at 110 ℃, then placing in the muffle furnace, and calcining for 4h at 400 ℃ in an argon atmosphere to obtain the modified perovskite catalyst. In the modified perovskite-type catalyst obtained in this example, the mass of Pt was 2.87% of the mass of the carrier, the mass of Ce was 5.31% of the mass of the carrier, and the mass of C was 10.52% of the mass of the carrier.

Example 2

Example 2 differed from example 1 only in that 52.2071g of sodium sulfate was used instead of 82.3298g of sodium bicarbonate in 700mL of deionized water.

Example 3

Example 3 differs from example 1 only in that 24.6616g of sodium sulfate and 38.8714g of sodium bicarbonate were used instead of 82.3298g of sodium bicarbonate dissolved in 700mL of deionized water.

Example 4

Example 4 differed from example 1 only in that 11.9828g of sodium sulfate and 18.9358g of sodium bicarbonate were used instead of 82.3298g of sodium bicarbonate dissolved in 700mL of deionized water.

Example 5

Example 5 differs from example 1 only in that 38.0067g of sodium sulfate and 59.9831g of sodium bicarbonate were used instead of 82.3298g of sodium bicarbonate dissolved in 700mL of deionized water.

Example 6

Example 6 differs from example 1 only in that 38.0067g of sodium sulfate and 18.9358g of sodium bicarbonate were used instead of 82.3298g of sodium bicarbonate dissolved in 700mL of deionized water.

Example 7

Example 7 differed from example 1 only in that 11.9828g of sodium sulfate and 59.9831g of sodium bicarbonate were used instead of 82.3298g of sodium bicarbonate in 700mL of deionized water.

Comparative example 1

The modified perovskite-type catalyst of comparative example 1 was the first intermediate obtained in example 1.

FIG. 1 is a Zeta potential diagram of the modified perovskite catalysts obtained in example 3 and comparative example 1, and it can be seen from FIG. 1 that the Zeta potential values of the perovskite catalysts modified with C and S are significantly higher than those of the perovskite catalysts not modified with C and S.

Comparative example 2

Comparative example 2 differs from example 1 only in that 33.6182g of ammonium nitrate was used instead of 82.3298g of sodium bicarbonate dissolved in 700mL of deionized water.

The modified perovskite catalysts prepared in examples 1-7, comparative example 1 and comparative example 2 are respectively used for treating aniline wastewater, and the TOC of the wastewater is 10000mg/L, and TN is 6300 mg/L. During treatment, the reaction temperature was 200 ℃, the oxygen partial pressure was 2.0MPa, the pH of the wastewater was adjusted to 5.5, the reaction time was 60min, and the TOC and TN removal rates were calculated after the reaction was completed, with the results shown in table 1.

TABLE 1

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.