Preparation method and application of micron rod-shaped polybrominated diphenyl ether oxidation catalyst

Abstract

The invention discloses a preparation method and application of a microrod-like polybrominated diphenyl ether oxidation catalyst, the catalyst is prepared by using straw as a main raw material, a composite oxide of titanium dioxide and ferroferric oxide as a carrier, platinum nanoparticles as an active component and copper oxide as a cocatalyst through a template hydrolysis-dipping roasting combined method. Based on the mass of the carrier, the mass percentage content of the active component is 0.5-2%, and the mass percentage content of the cocatalyst is 1-5%, and the catalyst synthesized by the method has excellent polybrominated diphenyl ether conversion rate, can realize efficient removal of new pollutants such as polybrominated diphenyl ether in water, and has high economic value and wide market application prospect.

Description

Technical Field

[0001] The present invention relates to the field of environmental protection catalysis technology, and specifically to a preparation method and application of a micron-rod-shaped polybrominated diphenyl ether oxidation catalyst. Background Art

[0002] Polybrominated diphenyl ethers (PBDEs), as emerging pollutants in wastewater, are a class of bromine-containing organic chemical compounds widely used as flame retardants in electronic products, household products, and other industrial products. However, long-term exposure to PBDEs can affect human brain development, leading to neurodevelopmental disorders such as inattention and learning difficulties, and can also interfere with the normal functions of human hormones, thereby affecting the health of metabolism and the immune system.

[0003] Catalytic oxidation technology is considered an effective means for treating organic pollutants. The core of this technology is to use a catalyst to promote the oxidation reaction, decompose and transform pollutants under mild conditions, and has the advantages of high selectivity, fast reaction speed, and low energy consumption. At present, researchers have developed a variety of catalysts, mainly including: metal oxide catalysts such as titanium dioxide (TiO), manganese oxide (MnO), iron oxide (FeO), etc., which have high catalytic activity and stability; noble metal catalysts such as platinum (Pt), palladium (Pd), etc., these catalysts have high catalytic activity and selectivity. However, noble metal catalysts are highly efficient but more costly, while metal oxide catalysts are less costly but have lower oxidation efficiency than noble metals. Therefore, developing and screening catalysts with appropriate costs and high efficiency is one of the key research directions at present. Summary of the Invention

[0004] The purpose of the present invention is to solve the problems of low oxidation efficiency and high cost of polybrominated diphenyl ethers, and to provide a preparation method and application of a micron-rod-shaped polybrominated diphenyl ether oxidation catalyst.

[0005] A preparation method of a micron-rod-shaped polybrominated diphenyl ether oxidation catalyst, characterized in that: the catalyst uses straw as the main raw material, a composite oxide of titanium dioxide and iron tetroxide as the carrier, platinum nanoparticles as the active component, and copper oxide as the promoter, and is prepared by a combined method of template hydrolysis-in-situ reduction-impregnation calcination, and based on the mass of the carrier, the mass percentage content of the active component is 0.5-2%, and the mass percentage content of the promoter is 1-5%, wherein the mass ratio of titanium dioxide to iron tetroxide in the carrier is 1:(0.1-0.3), and this method includes the following steps:

[0006] (1) Preparation of a composite oxide carrier by template hydrolysis method

[0007] Weigh and cut the straw into small sections, and then use deionized water, dilute sulfuric acid, and sodium hydroxide solution to wash and perform acid-base treatment on the small straw sections. After drying, ball-mill and screen them to obtain straw fiber powder. Then, place the straw fiber powder in an atmosphere furnace for high-temperature carbonization to obtain a micron-rod porous straw carbon material. Then, weigh titanium salt, iron salt, reducing agent, morphology control agent, absolute ethanol, acetic acid, deionized water, and the micron-rod porous straw carbon material, mix them evenly, hydrolyze at room temperature, perform hydrothermal reaction in a hydrothermal reaction kettle, filter and dry after the hydrothermal reaction, and then place them in a muffle furnace for high-temperature roasting to obtain a composite oxide micron-rod support;

[0008] (2) In-situ reduction method for loading active components

[0009] Weigh platinum salt and deionized water to form an active component precursor solution. Then, place the composite oxide micron-rod support prepared in step (1) in the active component precursor solution, impregnate it, and dry it in vacuum to obtain a micron-rod support loaded with platinum salt. Weigh sodium borohydride and deionized water to form a reducing agent solution. Then, place the micron-rod support loaded with platinum salt on the filter paper surface of a suction funnel, and pour the reducing agent solution into the suction funnel during the suction filtration process. After the reaction is completed, dry the micron-rod support loaded with platinum nanoparticles on the filter paper surface for standby;

[0010] (3) Catalyst preparation

[0011] Weigh copper salt and deionized water and mix them evenly to obtain a promoter precursor solution. Then, place the micron-rod support loaded with platinum nanoparticles prepared in step (2) in the promoter precursor solution, dry it, and roast it to obtain a catalyst.

[0012] In the technical solution of the present invention: the straw in step (1) is rice straw or wheat straw, the dilute sulfuric acid is a sulfuric acid solution with a mass fraction of 30-60%, the sodium hydroxide solution is a sodium hydroxide solution with a mass fraction of 20-50%, the length of the small straw section is 20-30 mm, and the mass ratio of straw, deionized water, dilute sulfuric acid, and sodium hydroxide solution is 1:(10-20):(30-50):(30-50).

[0013] In the technical solution of the present invention: the drying temperature in step (1) is 40-80 °C, the drying time is 24-48 h, the rotation speed of the ball mill is 300-500 rpm, the mass ratio of straw and zirconia balls during the ball milling process is 1:(3-5), the ball milling time is 1-3 h, and the mesh number of the metal sieve during the sieving process is 100-150 mesh.

[0014] In the technical solution of the present invention: the high-temperature carbonization temperature in step (1) is 600-800 °C, the high-temperature carbonization time is 2-4 h, the gas introduced into the atmosphere furnace during the high-temperature carbonization process is nitrogen, and the rate of nitrogen introduction is 20-30 mL / min.

[0015] In the technical solution of the present invention: in step (1), the titanium salt is tetrabutyl titanate or tetraethyl titanate, the iron salt is ferric nitrate nonahydrate or ferric chloride hexahydrate, the reducing agent is mannose or mannitol, the morphology control agent is triethylenetetramine or 1,3-diaminopropane, and the mass ratio of the titanium salt, the reducing agent, the morphology control agent, absolute ethanol, acetic acid, deionized water and the micro-rod porous straw carbon material is 1:(2-3):(0.5-1.0):(40-80):(5-10):(1-5):(2-4).

[0016] In the technical solution of the present invention: in step (1), the hydrolysis time is 6-12 h, the hydrothermal reaction temperature is 140-180 °C, the hydrothermal reaction time is 4-8 h, the drying temperature is 80-100 °C, the drying time is 12-24 h, the high-temperature roasting temperature is 500-700 °C, and the high-temperature roasting time is 3-6 h.

[0017] In the technical solution of the present invention: in step (2), the platinum salt is chloroplatinic acid, the mass ratio of the platinum salt to deionized water is 1:(80-160), the vacuum drying temperature is 40-60 °C, the vacuum drying time is 12-24 h, the mass ratio of sodium borohydride to deionized water is 1:(100-200), the mass ratio of the reducing agent solution to the micro-rod carrier loaded with the platinum salt is 1:(0.02-0.10), the reaction time is 5-10 min, the drying temperature is 40-80 °C, and the drying time is 6-12 h.

[0018] In the technical solution of the present invention: in step (3), the copper salt is copper nitrate or copper chloride, the mass ratio of the copper salt to deionized water is 1:(30-50), the drying temperature is 80-100 °C, the drying time is 4-8 h, the roasting temperature is 500-700 °C, and the roasting time is 3-6 h.

[0019] In the technical solution of the present invention, the catalyst prepared by the above method is used in the field of catalytic oxidation of new pollutants in wastewater.

[0020] Further: the new pollutants are polybrominated diphenyl ethers, specifically pentabromodiphenyl ether and octabromodiphenyl ether.

[0021] Beneficial effects:

[0022] (1) First, the present invention uses deionized water to wash biological straws, then uses dilute sulfuric acid to remove straw impurities and partially decompose its lignin, making the biological straw fibers easier to extract. Then, sodium hydroxide solution is used to break down the lignin and hemicellulose of the biological straws, promoting fiber separation. Finally, the biomass straws are made into straw fiber powders by ball milling and sieving, and micron rod-shaped porous straw carbon templates are formed through high-temperature carbonization. This method can not only utilize agricultural waste straws for high-value resource utilization, but also the prepared straw carbon has a micron rod shape and porous characteristics, which can be used as a biological template for catalytic materials to promote the formation of a micron rod-shaped structure of the catalyst;

[0023] (2) Compared with other biochar precursors, the straw used in the present invention has a wide source, low price and stable properties. Its organic matter and carbon content are higher, which is conducive to improving the yield and quality of biochar. At the same time, the cell wall and fiber structure of the straw endow it with a unique pore structure, making the biochar formed by its transformation have a higher specific surface area and porous structure, thus ensuring the stability of the catalyst morphology when it is used as a micron rod template material;

[0024] (3) The present invention uses mannose / mannitol as a reducing agent to partially reduce iron salts, which are finally transformed into magnetite under hydrothermal reaction conditions. At the same time, triethylenetetramine / 1,3-diaminopropane is used to form complexes with iron ions, ferrous ions, titanium ions, etc., thereby promoting the deposition of iron salts and titanium salts on the surface of the micron rod porous straw carbon during the hydrothermal process. Finally, the straw carbon is removed by calcination to form a composite oxide micron rod carrier. The composite oxide of titanium dioxide and magnetite as a carrier not only has the advantage of the high specific surface area of titanium dioxide, but also the two metal oxides can form solid acids, improving the surface acidity of the catalyst and promoting the improvement of catalytic performance. At the same time, magnetite can ensure that the catalyst can be recycled by magnetic force after catalytically oxidizing polybrominated diphenyl ethers in wastewater;

[0025] (4) The present invention uses an in-situ reduction method to reduce platinum salts to platinum nanoparticles. First, the composite oxide micron rods are used to adsorb platinum salts, and then they are placed on the surface of a filter paper. During the suction filtration process, the reducing agent is poured into the suction filtration funnel. The reducing agent sodium borohydride solution is quickly suction filtered into a conical flask after reacting with the platinum salts. This method can avoid the problem that platinum salts are not adsorbed and grown on the surface of the carrier after being reduced by sodium borohydride in the conventional in-situ reduction method. Its main principle is to quickly remove the gas generated by the reaction of sodium borohydride and platinum salts by suction filtration, avoiding the accumulation of gas on the surface of the carrier in the conventional in-situ reduction method and promoting the separation of platinum nanoparticles from the carrier;

[0026] (4) The present invention uses copper oxide as a co-catalyst, which has excellent oxidation performance and electron transport performance, and can further promote the surface electron migration of platinum nanoparticles, thereby improving catalytic performance;

[0027] (5) This preparation method has a simple process and common raw materials, with broad market application prospects and high economic value. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Appendix Figure 1 Field emission scanning electron microscope image of the catalyst in Example 1;

[0029] Appendix Figure 2 Catalytic oxidation efficiency diagrams of pentabromodiphenyl ether in Examples 1 to 3;

[0030] Appendix Figure 3 Catalytic oxidation efficiency diagrams of octabromodiphenyl ether in Examples 1 to 3. DETAILED DESCRIPTION OF THE INVENTION

[0031] Example 1

[0032] (1) Preparation of composite oxide support by template hydrolysis method

[0033] Weigh 100 g of rice straw and cut it into small sections of 20 mm, soak it in 1000 g of deionized water for 2 h, filter it out and then soak it in 3000 g of 30% dilute sulfuric acid for 4 h, filter it out and then soak it in 3000 g of 20% sodium hydroxide solution for 4 h, and then filter it out and place it in an oven to dry at 40 °C for 48 h; weigh 50 g of the acid- and alkali-treated small sections of rice straw and 150 g of zirconia balls and add them to a ball mill jar, perform planetary ball milling at a speed of 300 rpm for 3 h, and then sieve them using 100-mesh and 150-mesh metal sieves to obtain rice straw fiber powder between 100 and 150 meshes. Then weigh 40 g of the rice straw fiber powder and place it in an atmosphere furnace to be carbonized at 600 °C for 4 h (the gas introduced into the atmosphere furnace during the high-temperature carbonization process is nitrogen, and the rate of nitrogen introduction is 20 mL / min) to obtain a micron-rod porous straw carbon material; then weigh 5 g of tetrabutyl titanate, 0.614 g of ferric nitrate nonahydrate, 10 g of mannose, 2.5 g of triethylenetetramine, 200 g of absolute ethanol, 25 g of acetic acid, 5 g of deionized water, and 10 g of the micron-rod porous straw carbon material, mix them evenly, hydrolyze them at room temperature for 6 h, and then place them in a hydrothermal reaction kettle for hydrothermal reaction at 140 °C for 8 h. After the hydrothermal reaction is completed, filter them and place them in an oven to dry at 80 °C for 24 h, and then place them in a muffle furnace to be calcined at 500 °C for 6 h to obtain a composite oxide micron-rod support;

[0034] (2) Loading of active components by in-situ reduction method

[0035] Weigh 10.5 mg of chloroplatinic acid and 1.68 g of deionized water and mix them to form an active component precursor solution. Then, weigh 1 g of the composite oxide micro-rod support prepared in step (1) and place it in the active component precursor solution. After impregnation, dry it in vacuum at 40 °C for 24 h to obtain a micro-rod support loaded with chloroplatinic acid. Weigh 1 g of sodium borohydride and 100 g of deionized water and mix them to form a sodium borohydride solution. Then, place the micro-rod support loaded with chloroplatinic acid on the filter paper surface of a suction filter funnel. During the suction filtration process, pour 50.525 g of the sodium borohydride solution into the suction filter funnel. After reacting for 10 min, place the micro-rod support loaded with platinum nanoparticles on the filter paper surface in an oven and dry it at 40 °C for 12 h for standby.

[0036] (3) Catalyst preparation

[0037] Weigh 23.6 mg of copper nitrate and 1.18 g of deionized water and mix them evenly to obtain a promoter precursor solution. Then, place the micro-rod support loaded with platinum nanoparticles prepared in step (2) in the promoter precursor solution. After drying at 80 °C for 8 h, calcine it to obtain a catalyst (based on the mass of the support, the mass percentage of the active component is 0.5%, and the mass percentage of the promoter is 1%. Among them, the mass ratio of titanium dioxide to iron tetroxide in the support is 1:0.1. The field emission scanning electron microscope image of the catalyst is as Figure 1 shown);

[0038] (4) Catalytic activity test

[0039] Take 1 g of the catalyst with a mesh size of 80 - 100 and pour it into a beaker. Add 100 mL of the reaction solution for performance evaluation. The concentration of the reaction solution is: pentabromodiphenyl ether (5 μg / L when in use), octabromodiphenyl ether (5 μg / L when in use), hydrogen peroxide (1%). Use a gas chromatography - mass spectrometry instrument to measure the concentrations of pentabromodiphenyl ether and octabromodiphenyl ether. At normal temperature and pressure, the removal efficiencies of pentabromodiphenyl ether and octabromodiphenyl ether by the catalyst reach 91.4% and 83.2% respectively within 30 min.

[0040] Example 2

[0041] (1) Preparation of composite oxide support by template hydrolysis method

[0042] Weigh 100 g of wheat straw, cut it into small segments of 30 mm, soak it in 2000 g of deionized water for 2 h, filter and take it out, then soak it in 5000 g of dilute sulfuric acid with a mass fraction of 60% for 4 h, filter and take it out, then soak it in 5000 g of sodium hydroxide solution with a mass fraction of 50% for 4 h, and then filter and take it out and place it in an oven to dry at 80 °C for 24 h; Weigh 50 g of the acid-alkali treated small wheat straw segments and 250 g of zirconia balls, add them to a ball mill jar, perform planetary ball milling at a speed of 500 rpm for 1 h, and then sieve them using metal sieves with 100 meshes and 150 meshes to obtain wheat straw fiber powder between 100 and 150 meshes. Then weigh 40 g of wheat straw fiber powder and place it in an atmosphere furnace for high-temperature carbonization at 800 °C for 2 h (the gas introduced into the atmosphere furnace during high-temperature carbonization is nitrogen, and the rate of nitrogen introduction is 30 mL / min) to obtain a micro-rod porous straw carbon material; Then weigh 2.5 g of tetraethyl titanate, 0.920 g of ferric chloride hexahydrate, 7.5 g of mannitol, 2.5 g of 1,3-diaminopropane, 200 g of absolute ethanol, 25 g of acetic acid, 12.5 g of deionized water and 10 g of the micro-rod porous straw carbon material, mix them evenly, hydrolyze at room temperature for 12 h, then place them in a hydrothermal reaction kettle for hydrothermal reaction at 180 °C for 4 h. After the hydrothermal reaction, filter and place them in an oven to dry at 100 °C for 12 h, and then place them in a muffle furnace for high-temperature roasting at 700 °C for 3 h to obtain a composite oxide micro-rod support;

[0043] (2) In-situ reduction method for loading active components

[0044] Weigh 42.0 mg of chloroplatinic acid and 3.36 g of deionized water to form an active component precursor solution. Then weigh 1 g of the composite oxide micro-rod support prepared in step (1) and place it in the active component precursor solution. After impregnation, dry it in vacuum at 60 °C for 12 h to obtain a micro-rod support loaded with chloroplatinic acid; Weigh 1 g of sodium borohydride and 150 g of deionized water to form a sodium borohydride solution. Then place the micro-rod support loaded with chloroplatinic acid on the filter paper surface of a suction funnel. During the suction filtration process, pour 10.2 g of the sodium borohydride solution into the suction funnel. After reacting for 5 min, place the micro-rod support loaded with platinum nanoparticles on the filter paper surface in an oven to dry at 80 °C for 6 h for standby;

[0045] (3) Catalyst preparation

[0046] Weigh 84.5 mg of copper chloride and 2.535 g of deionized water, mix them evenly to obtain a promoter precursor solution. Then place the micro-rod support loaded with platinum nanoparticles prepared in step (2) in the promoter precursor solution, dry it at 100 °C for 4 h and then calcine it to obtain a catalyst (based on the mass of the support, the mass percentage content of the active component is 2%, and the mass percentage content of the promoter is 5%. Among them, the mass ratio of titanium dioxide to iron tetroxide in the support is 1:0.3);

[0047] (4) Catalytic activity test

[0048] Take 1 g of the catalyst with a particle size of 80 - 100 mesh, pour it into a beaker, and add 100 mL of the reaction solution for performance evaluation. The concentration of the reaction solution is: pentabromodiphenyl ether (5 μg / L when in use), octabromodiphenyl ether (5 μg / L when in use), hydrogen peroxide (1%). The concentrations of pentabromodiphenyl ether and octabromodiphenyl ether are measured using a gas chromatography - mass spectrometry (GC - MS) instrument. At normal temperature and pressure, the removal efficiencies of pentabromodiphenyl ether and octabromodiphenyl ether by the catalyst reach 96.8% and 89.8% respectively within 30 min.

[0049] Example 3

[0050] (1) Preparation of composite oxide support by template hydrolysis method

[0051] Weigh 100 g of wheat straw, cut it into small segments of 25 mm, soak it in 1500 g of deionized water for 2 h, filter and take it out, then soak it in 4000 g of 40% dilute sulfuric acid for 4 h, filter and take it out, then soak it in 4000 g of 30% sodium hydroxide solution for 4 h, and then filter and take it out and place it in an oven at 60 °C for drying for 36 h; Weigh 50 g of the acid - base treated small wheat straw segments and 200 g of zirconia balls, add them to a ball - milling tank, and perform planetary ball - milling at a speed of 400 rpm for 2 h, then sieve them using 100 - mesh and 150 - mesh metal sieves to obtain wheat straw fiber powder with a particle size between 100 - 150 mesh. Then weigh 40 g of the wheat straw fiber powder and place it in an atmosphere furnace for high - temperature carbonization at 700 °C for 3 h (the gas introduced into the atmosphere furnace during high - temperature carbonization is nitrogen, and the rate of nitrogen introduction is 25 mL / min) to obtain a micro - rod porous straw carbon material; Then weigh 5 g of tetrabutyl titanate, 0.822 g of ferric chloride hexahydrate, 12.5 g of mannose, 3.5 g of 1,3 - diamino propane, 300 g of absolute ethanol, 35 g of acetic acid, 15 g of deionized water, and 10 g of the micro - rod porous straw carbon material, mix them evenly, hydrolyze at room temperature for 10 h, then place them in a hydrothermal reaction kettle for hydrothermal reaction at 160 °C for 6 h. After the hydrothermal reaction, filter and place it in an oven at 90 °C for drying for 18 h, and then place it in a muffle furnace for high - temperature roasting at 600 °C for 4 h to obtain a composite oxide micro - rod support;

[0052] (2) Loading of active components by in - situ reduction method

[0053] Weigh 21.0 mg of chloroplatinic acid and 2.1 g of deionized water and mix them to form an active component precursor solution. Then, weigh 1 g of the composite oxide micro-rod support prepared in step (1) and place it in the active component precursor solution. After impregnation, dry it in vacuum at 50 °C for 16 h to obtain a micro-rod support loaded with chloroplatinic acid. Weigh 1 g of sodium borohydride and 200 g of deionized water and mix them to form a sodium borohydride solution. Then, place the micro-rod support loaded with chloroplatinic acid on the filter paper surface of a suction funnel. During the suction filtration process, pour 20.2 g of the sodium borohydride solution into the suction funnel. After reacting for 7 min, place the micro-rod support loaded with platinum nanoparticles on the filter paper surface in an oven and dry it at 60 °C for 10 h for standby;

[0054] (3) Catalyst preparation

[0055] Weigh 70.7 mg of copper nitrate and 2.828 g of deionized water and mix them evenly to obtain a promoter precursor solution. Then, place the micro-rod support loaded with platinum nanoparticles prepared in step (2) in the promoter precursor solution. After drying at 90 °C for 6 h, calcine it to obtain a catalyst (based on the mass of the support, the mass percentage of the active component is 1%, and the mass percentage of the promoter is 3%. Among them, the mass ratio of titanium dioxide to iron tetroxide in the support is 1:0.2);

[0056] (4) Catalytic activity test

[0057] Take 1 g of the catalyst with a particle size of 80 - 100 mesh, pour it into a beaker and add 100 mL of the reaction solution for performance evaluation. The concentration of the reaction solution is: pentabromodiphenyl ether (5 μg / L when in use), octabromodiphenyl ether (5 μg / L when in use), hydrogen peroxide (1%). Use a gas chromatography - mass spectrometry instrument to measure the concentrations of pentabromodiphenyl ether and octabromodiphenyl ether. At normal temperature and pressure, the removal efficiencies of the catalyst for pentabromodiphenyl ether and octabromodiphenyl ether reach 94.9% and 87.1% respectively within 30 min.

[0058] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A preparation method of a micron rod-shaped polybrominated diphenyl ether oxidation catalyst, characterized in that: The catalyst uses straw as the main raw material, a composite oxide of titanium dioxide and iron trioxide as the carrier, platinum nanoparticles as the active component, and copper oxide as the promoter. It is prepared by a combined method of template hydrolysis-in-situ reduction-impregnation calcination. Based on the mass of the carrier, the mass percentage of the active component is 0.5-2%, and the mass percentage of the promoter is 1-5%. Among them, the mass ratio of titanium dioxide to iron trioxide in the carrier is 1:(0.1-0.3). The method includes the following steps: (1) Preparation of the composite oxide carrier by template hydrolysis method Weigh and cut the straw into small sections, and then wash and perform acid-base treatment on the small sections of straw using deionized water, dilute sulfuric acid, and sodium hydroxide solution respectively. After drying, ball mill and sieve to obtain straw fiber powder. Then place the straw fiber powder in an atmosphere furnace for high-temperature carbonization to obtain a micron-rod porous straw carbon material. Then weigh titanium salt, iron salt, reducing agent, morphology control agent, anhydrous ethanol, acetic acid, deionized water, and the micron-rod porous straw carbon material, mix them evenly, hydrolyze at room temperature, perform hydrothermal reaction in a hydrothermal reaction kettle after hydrolysis, filter and dry after the hydrothermal reaction is completed, and then place it in a muffle furnace for high-temperature calcination to obtain a composite oxide micron-rod carrier; (2) Loading of the active component by in-situ reduction method Weigh platinum salt and deionized water to form an active component precursor solution. Then place the composite oxide micron-rod carrier prepared in step (1) in the active component precursor solution, impregnate and then vacuum dry to obtain a micron-rod carrier loaded with platinum salt. Weigh sodium borohydride and deionized water to form a reducing agent solution. Then place the micron-rod carrier loaded with platinum salt on the filter paper surface of a suction funnel, and pour the reducing agent solution into the suction funnel during the suction filtration process. After the reaction is completed, dry the micron-rod carrier loaded with platinum nanoparticles on the filter paper surface for standby; (3) Catalyst preparation Weigh copper salt and deionized water, mix them evenly to obtain a promoter precursor solution. Then place the micron-rod carrier loaded with platinum nanoparticles prepared in step (2) in the promoter precursor solution, dry and then calcine to obtain the catalyst.

2. The preparation method according to claim 1, wherein: The straw described in step (1) is rice straw or wheat straw, the dilute sulfuric acid is a sulfuric acid solution with a mass fraction of 30-60%, the sodium hydroxide solution is a sodium hydroxide solution with a mass fraction of 20-50%, the length of the small sections of straw is 20-30 mm, and the mass ratio of straw, deionized water, dilute sulfuric acid, and sodium hydroxide solution is 1:(10-20):(30-50):(30-50).

3. The preparation method according to claim 1, wherein: The drying temperature described in step (1) is 40-80 °C, the drying time is 24-48 h, the rotation speed of the ball mill is 300-500 rpm, the mass ratio of straw to zirconia balls during the ball milling process is 1:(3-5), the ball milling time is 1-3 h, and the mesh number of the metal sieve during the sieving process is 100-150 mesh.

4. The preparation method according to claim 1, characterized in that: The high-temperature carbonization temperature described in step (1) is 600-800 °C, the high-temperature carbonization time is 2-4 h, the gas introduced into the atmosphere furnace during the high-temperature carbonization process is nitrogen, and the rate of nitrogen introduction is 20-30 mL / min.

5. The preparation method according to claim 1, wherein: The titanium salt described in step (1) is tetrabutyl titanate or tetraethyl titanate, the iron salt is ferric nitrate nonahydrate or ferric chloride hexahydrate, the reducing agent is mannose or mannitol, the morphology control agent is triethylenetetramine or 1,3-diaminopropane, and the mass ratio of the titanium salt, reducing agent, morphology control agent, absolute ethanol, acetic acid, deionized water and the micro-rod porous straw carbon material is 1:(2-3):(0.5-1.0):(40-80):(5-10):(1-5):(2-4).

6. The preparation method according to claim 1, characterized in that: The hydrolysis time described in step (1) is 6-12 h, the hydrothermal reaction temperature is 140-180 °C, the hydrothermal reaction time is 4-8 h, the drying temperature is 80-100 °C, the drying time is 12-24 h, the high-temperature calcination temperature is 500-700 °C, and the high-temperature calcination time is 3-6 h.

7. The preparation method according to claim 1, characterized in that: The platinum salt described in step (2) is chloroplatinic acid, the mass ratio of the platinum salt and deionized water is 1:(80-160), the vacuum drying temperature is 40-60 °C, the vacuum drying time is 12-24 h, the mass ratio of sodium borohydride and deionized water is 1:(100-200), the mass ratio of the reducing agent solution and the micro-rod carrier loaded with the platinum salt is 1:(0.02-0.10), the reaction time is 5-10 min, the drying temperature is 40-80 °C, and the drying time is 6-12 h.

8. The preparation method according to claim 1, wherein: The copper salt described in step (3) is copper nitrate or copper chloride, the mass ratio of the copper salt and deionized water is 1:(30-50), the drying temperature is 80-100 °C, the drying time is 4-8 h, the calcination temperature is 500-700 °C, and the calcination time is 3-6 h.

9. Application of the catalyst prepared by the method according to claim 1 in the field of catalytic oxidation of new pollutants in wastewater.

10. The application according to claim 9, characterized in that: The new pollutants are polybrominated diphenyl ethers, specifically pentabromodiphenyl ether and octabromodiphenyl ether.

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