Preparation method and application of black phosphorus oxidation liquid modified catalyst carrier

Abstract

The present invention relates to a preparation method and application of a black phosphorus oxidizing liquid modified catalyst carrier. Black phosphorus micropowder is first treated with an oxidant solution to obtain a black phosphorus oxidizing liquid, and then the catalyst carrier is treated by three methods: impregnation, heating reflux, and spraying. Finally, precious metals are loaded for industrial hydrogenation reactions. Black phosphorus nanosheets can react with precious metals, thereby changing the catalytic effect of the catalyst, and the oxidizing property of the oxidant can directly peel off the black phosphorus micropowder into black phosphorus nanosheets. Compared with traditional ultrasonic peeling, it saves time and energy and is easy to operate. In addition, the oxidant can oxidize the black phosphorus nanosheets into hypophosphorous acid substances and etch the surface of the carrier at the same time, thereby strengthening the bonding strength between the precious metal and the carrier. Test results show that all three treatment methods can increase the precious metal loading of the carrier and extend the service life of the catalyst.

Description

Technical Field

[0001] The present invention relates to the technical field of catalyst carrier preparation, and in particular to a method for modifying a catalyst carrier with a black phosphorus oxidizing solution and application thereof. Background Art

[0002] Since black phosphorus was successfully exfoliated in 2014, it has attracted widespread attention from scientists around the world. It has a two-dimensional layered structure similar to graphene. Each central phosphorus atom is covalently bonded to the three surrounding phosphorus atoms, and the layers are stacked by van der Waals forces. The unique structure gives black phosphorus good chemical properties. Therefore, black phosphorus is widely used in optoelectronic materials, catalytic materials, energy and environmental materials, and biomedical materials. CN201710182141.3 discloses a method for preparing a composite material of black phosphorus nanosheets and noble metal nanoparticles, using the exfoliated black phosphorus nanosheets as a carrier and using palladium salts for in-situ reduction to obtain the composite material. CN202110102573.5 discloses a method for preparing a black phosphorus-treated copper-based catalyst and its application in the synthesis of dichlorodimethylsilane. ZL201710131707.X discloses a method for preparing black phosphorus and titanium dioxide heterojunction materials loaded with precious metal nanoparticles, wherein titanium dioxide nanosheet materials and black phosphorus nanosheet materials are ball-milled under inert gas protection to prepare a carrier material.

[0003] Oxidants are substances that gain electrons during redox reactions and are widely used in a wide range of industries, including aerospace, biomedicine, and energy materials. In the field of catalytic materials, oxidants can modify or etch the surface of materials, altering their physical and chemical parameters and thus their catalytic performance.

[0004] Hydrogenation is a major reaction type in industrial production, widely used in various fields of petrochemicals and fine chemicals. It plays a vital role in raw material refining, reaction processes, product refining, and waste treatment. Almost all hydrogenation reactions occur in the presence of catalysts. Precious metal catalysts are widely used in hydrogenation reactions due to their significant advantages such as high activity and high selectivity. According to incomplete statistics, at least 60% of hydrogenation catalysts use precious metal catalysts, such as Pd / Al2O3 in the hydrogenation of anthraquinone to hydrogen peroxide, Pd / C in the hydrogenation of nitrobenzene to aniline, and ruthenium catalysts in the hydrogenation of benzene to cyclohexene. Currently, industrial catalysts are commonly prepared by impregnation, where a support is soaked with a precious metal salt solution. However, this process is plagued by challenges such as incomplete loading of the active metal and difficulty recovering the precious metal from the residual solution. Therefore, there is an urgent need to develop efficient processes for loading precious metal catalysts. Summary of the Invention

[0005] The present invention provides a method for modifying a catalyst carrier with a black phosphorus oxidizing liquid, which can effectively increase the precious metal loading and service life of a hydrogenation reaction catalyst and reduce the production cost of the catalyst.

[0006] The technical solutions adopted in the present invention are as follows:

[0007] (1) The catalyst support is dried before use;

[0008] (2) using an oxidant to oxidize the black phosphorus powder to obtain a black phosphorus oxidation solution;

[0009] (3) The catalyst carrier is treated with black phosphorus oxidation liquid and then dried to obtain a black phosphorus modified carrier.

[0010] In some preferred embodiments, the catalyst carrier described in step (1) includes one or more of alumina, silica, carbon carrier, titanium dioxide, zirconium dioxide, phosphate, sulfate molecular sieve, and hydrotalcite; the drying method is one or more of forced air drying, vacuum drying, or drying under an inert atmosphere; the drying temperature is 100°C-200°C, and the drying time is 2h-8h.

[0011] In some preferred embodiments, the oxidant in step (2) includes one or more of potassium permanganate, hydrogen peroxide, sodium hypochlorite, peracetic acid, potassium dichromate, and sodium persulfate; the oxidant solution solvent can be one or more of water, ethanol, N-methylpyrrolidone, acetone, N,N-dimethylformamide, dimethyl sulfoxide, methanol, and isopropanol.

[0012] In some preferred embodiments, the black phosphorus powder in step (2) is prepared by mixing one or both of ball milling and jet milling.

[0013] In some preferred embodiments, the mass ratio of the black phosphorus powder to the oxidant used in step (2) is 1:1-1:20, and the treatment time is 2-6 hours.

[0014] In some preferred embodiments, the mass ratio of the catalyst support to the black phosphorus oxidation solution in step (3) is 5:1-1000:1:

[0015] In some preferred embodiments, the treatment of the catalyst support with the black phosphorus oxidizing solution in step (3) includes one or more of heating and reflux under an inert atmosphere, inert gas impregnation and calcination, and surface spraying.

[0016] The reflux temperature of the heating reflux under the inert gas atmosphere is 60° C.-180° C., the reflux time is 10-40 hours, and the inert gas is any one of N 2 and Ar or a mixed gas.

[0017] The impregnation method in the inert gas impregnation roasting is one of equal volume impregnation or supersaturation impregnation, the impregnation time is 0.5-4h, the roasting temperature is 200℃-350℃, the roasting time is 2-12h, and the inert gas is any one of N2, Ar or a mixed gas.

[0018] The surface spraying is carried out by an atomizer or a spray tower, the nozzle pressure is 0.05-0.2MPa, the spraying temperature is 20°C-60°C, and the ratio of the volume of the liquid used for spraying to the volume of the catalyst carrier pile is 1:1-2:1;

[0019] In some preferred embodiments, the drying method in step (3) is one or more of forced air drying, vacuum drying or drying under an inert atmosphere; the drying temperature is 60° C.-160° C., and the drying time is 2 h-12 h.

[0020] The present invention has no special requirements on the preparation method of the catalyst carrier and the loading method of the noble metal active component. Molded and powder carriers well known to those skilled in the art are within the scope of protection of the present invention.

[0021] The present invention provides a method for preparing a black phosphorus oxidizing liquid modified catalyst carrier described in the above technical solution, and an application of the catalyst carrier in a catalyst hydrogenation reaction after loading a noble metal active component.

[0022] The beneficial effects of the present invention are:

[0023] 1. The present invention provides a preparation method and application of a black phosphorus oxidizing liquid-modified catalyst carrier. Black phosphorus nanosheets, as an excellent two-dimensional layered material, can combine with noble metal atoms to change the catalytic effect of noble metal catalysts. The oxidant can etch and chemically strip the black phosphorus micropowder, and it can be stripped into black phosphorus nanosheets and black phosphorus quantum dots without the need for ultrasonic crushing, effectively avoiding the low efficiency and high energy consumption problems brought about by traditional ultrasonic crushing.

[0024] 2. The oxidant in the present invention can oxidatively modify the surface of black phosphorus to generate a hypophosphorous acid-like substance, thereby increasing the bonding strength with the precious metal, increasing the loading amount of the precious metal on the carrier, and effectively extending the service life of the catalyst.

[0025] 3. The carrier modification process used in the present invention does not require the use of complex processes such as high-temperature and high-pressure equipment, which is beneficial to the industrial production of catalysts and has certain technical and economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is the life test chart of Pd / HP-BP-Al2O3-8 and comparative catalyst samples.

[0027] Figure 2This is a physical picture of the spherical alumina carrier.

[0028] Figure 3 These are pictures before and after the black phosphorus powder was oxidized with hydrogen peroxide in Example 1. A is a picture of the black phosphorus powder particles before oxidation; B is a picture of the black phosphorus powder after oxidation with hydrogen peroxide. DETAILED DESCRIPTION

[0029] The present invention provides a method for preparing a catalyst support modified with a black phosphorus oxidizing liquid and its application. The black phosphorus oxidizing liquid is used to oxidize black phosphorus micropowder through an oxidant. The application involves loading the modified catalyst support with a precious metal and then using it in an industrial hydrogenation reaction. The present invention does not require any special catalyst support preparation process; any powdered or shaped catalyst support known to those skilled in the art falls within the scope of the present invention.

[0030] To make the objectives, technical solutions, and advantages of the present invention more clearly understood, the present invention is described in detail below with reference to the accompanying drawings and examples. It should be noted that the specific examples described herein are only used to explain the present invention and are not intended to limit the embodiments of the present invention. Any other changes, modifications, combinations, simplifications, and substitutions made without departing from the spirit and principles of the present invention shall be considered equivalent replacement methods and shall be included within the scope of protection of the present invention.

[0031] Comparative Example

[0032] The preparation method of catalyst loading is as follows: using alumina microspheres as the carrier, at 60°C, according to the theoretical mass fraction of 0.3% palladium loading, equal volume impregnation, 0.003 parts by mass of PdCl2 and 0.002 parts by mass of NaCl prepared by Na2PdCl4 solution is added dropwise to 0.6 parts by mass of alumina microspheres, after stirring evenly, sealed and placed in a drying oven at 60°C for 2 hours, then the precipitate is taken and washed until there is no chloride ion, and then the filter cake is dried; further, the dried product is calcined at 500°C for 2 hours, and after naturally cooling to room temperature, the palladium catalyst is obtained.

[0033] Example 1

[0034] First, 1g of black phosphorus crystals was weighed, crushed, and placed in a 100mL agate grinding jar. 50g of 10mm agate grinding balls were added and ball-milled at 300r / min for 4h before removing the powder. All the black phosphorus powder was removed and added to a hydrogen peroxide solution at a mass ratio of 20:1 to black phosphorus powder. After reacting for 6h, black phosphorus oxidation solution 1 was obtained. A spherical alumina support, dried at 100°C for 8h, was added at a mass ratio of 1:10 to the spherical alumina support. The solution was heated to reflux at 60°C under N2 for 40h. After reflux, it was dried at 60°C for 12h to obtain black phosphorus oxidation solution-modified alumina 1. The catalyst Pd / HP-BP-Al2O3-1 was obtained after palladium loading using the comparative example.

[0035] The black phosphorus oxidation solution modified alumina support and palladium catalyst were prepared according to Example 1. The difference from Example 1 was that the black phosphorus oxidation solution was used to treat the alumina support by an equal volume impregnation and roasting method of inert gas. Anhydrous ethanol was added to the oxidation solution to supplement the volume of the spherical alumina support in a ratio of 1 volume of black phosphorus oxidation solution to 1 volume of spherical alumina support for impregnation. The impregnation time was 0.5 h (from Figure 3 It can be seen that a transparent clear solution is formed after oxidation), and then calcined at 200°C for 12h under N2 atmosphere to obtain black phosphorus oxidation liquid modified alumina 2, which was treated by the comparative example of palladium loading to obtain the catalyst Pd / HP-BP-Al2O3-2.

[0036] A black phosphorus oxidizing liquid modified alumina carrier and a palladium catalyst were prepared according to Example 1. The difference from Example 1 was that the black phosphorus oxidizing liquid was used to treat the spherical alumina carrier by spraying with an atomizer. Anhydrous ethanol was added to the oxidizing liquid in a ratio of 1 volume of black phosphorus oxidizing liquid to 1 volume of alumina for spraying. The nozzle pressure was 0.05 MPa, the spraying temperature was 20°C, and after the spraying was completed, the black phosphorus oxidizing liquid modified alumina 3 was obtained after drying with forced air at 60°C for 12 hours. The catalyst Pd / HP-BP-Al2O3-3 was obtained after treatment using the palladium loading method of the comparative example.

[0037] Example 2

[0038] First, 1g of black phosphorus crystals was weighed, crushed, and placed in a 100mL agate grinding jar. 50g of 10mm agate grinding balls were added and ball-milled at 300r / min for 4h before removing the powder. 0.2g of black phosphorus powder was added to hydrogen peroxide solution at a mass ratio of 10:1 to black phosphorus powder, and the mixture was reacted for 4h to obtain black phosphorus oxidation solution 2. A spherical alumina support, dried at 130°C for 4h, was placed in a mass ratio of 1:100 to the spherical alumina support. The mixture was heated to 80°C for 20h under N2 conditions and then dried at 80°C for 8h after reflux to obtain black phosphorus oxidation solution-modified alumina 4. The catalyst Pd / HP-BP-Al2O3-4 was obtained after palladium loading using the comparative example.

[0039] According to Example 2, a black phosphorus oxidizing liquid modified alumina carrier and a palladium catalyst were prepared. The difference from Example 2 is that the black phosphorus oxidizing liquid treated the alumina carrier by an inert gas supersaturated volume impregnation and roasting method. Anhydrous ethanol was added to the oxidizing liquid in a ratio of 2 volumes of black phosphorus oxidizing liquid to the volume of the spherical alumina carrier of 1.5:1 to supplement the volume for impregnation. The impregnation time was 1 hour. The alumina 5 modified with black phosphorus oxidizing liquid was obtained by roasting at 280°C for 5 hours under N2 atmosphere. The catalyst Pd / HP-BP-Al2O3-5 was obtained after treatment by the comparative example of palladium loading.

[0040] According to Example 2, a black phosphorus oxidizing liquid modified alumina carrier and a palladium catalyst were prepared. The difference from Example 2 was that the black phosphorus oxidizing liquid was used to treat the spherical alumina carrier by spraying with an atomizer. Anhydrous ethanol was added to the oxidizing liquid in a ratio of 1.5:1 between the volume of black phosphorus oxidizing liquid and the volume of alumina for spraying. The nozzle pressure was 0.08 MPa, the spraying temperature was 50°C, and after the spraying was completed, the black phosphorus oxidizing liquid modified alumina 6 was obtained after air drying at 80°C for 6 hours. The catalyst Pd / HP-BP-Al2O3-6 was obtained after treatment using the palladium loading method of the comparative example.

[0041] According to Example 2, a black phosphorus oxidation liquid-modified alumina carrier and a palladium catalyst were prepared. The difference from the Pd / HP-BP-Al2O3-4 product is that the black phosphorus micropowder was prepared by air flow milling, using N2 as the grinding gas, a pressure of 0.8 MPa, a rotation frequency of 90 Hz, and an air blowing pressure of 0.5 MPa. Finally, a black phosphorus oxidation liquid-modified spherical alumina carrier 7 was obtained, and the catalyst Pd / HP-BP-Al2O3-7 was obtained after treatment using the comparative example of palladium loading.

[0042] According to Example 2, a black phosphorus oxidizing liquid modified alumina carrier and a palladium catalyst were prepared. The difference from Example 2 is that the black phosphorus oxidizing liquid treated the alumina carrier by an inert gas supersaturated volume impregnation and roasting method. Deionized water was added to the oxidizing liquid in a ratio of 1.5:1 between the volume of the black phosphorus oxidizing liquid and the volume of the spherical alumina carrier for impregnation. The impregnation time was 1 hour. The alumina 8 was modified with black phosphorus oxidizing liquid and roasted at 280°C for 5 hours under a N2 atmosphere. The catalyst Pd / HP-BP-Al2O3-8 was obtained after treatment using the comparative example of palladium loading.

[0043] According to Example 2, a black phosphorus oxidizing liquid-modified alumina carrier and a palladium catalyst were prepared. The difference from Example 2 was that the black phosphorus oxidizing liquid was used to treat the spherical alumina carrier by spraying with an atomizer. Acetone was added to the oxidizing liquid in a ratio of 1.5:1 between the volume of black phosphorus oxidizing liquid and the volume of alumina for spraying. The nozzle pressure was 0.08 MPa, the spraying temperature was 50°C, and after the spraying was completed, the black phosphorus oxidizing liquid-modified alumina 6 was obtained after air drying at 80°C for 6 hours. The catalyst Pd / HP-BP-Al2O3-9 was obtained after treatment using the palladium-loaded method of the comparative example.

[0044] Example 3

[0045] First, 1g of black phosphorus crystals was weighed, crushed, and placed in a 100mL agate grinding jar. 50g of 10mm agate grinding balls were added and ball-milled at 300r / min for 4h before removing the powder. 0.1g of black phosphorus powder was added to a hydrogen peroxide solution at a mass ratio of 1:1 to black phosphorus powder. After reacting for 4h, black phosphorus oxidation solution 3 was obtained. A spherical alumina support, dried at 200°C for 2h, was placed in a mass ratio of 1:1000 of black phosphorus oxidation solution to spherical alumina support. The solution was then heated to reflux at 180°C under N2 for 10h. After reflux, the solution was dried at 160°C for 2h to obtain black phosphorus oxidation solution-modified alumina 10. This was then treated using the palladium loading method of the comparative example to obtain the catalyst Pd / HP-BP-Al2O3-10.

[0046] According to Example 3, a black phosphorus oxidizing liquid modified alumina carrier and a palladium catalyst were prepared. The difference from Example 3 is that the black phosphorus oxidizing liquid treated the alumina carrier by an inert gas supersaturated volume impregnation and roasting method. Anhydrous ethanol was added to the oxidizing liquid in a ratio of 2:1 between the volume of the black phosphorus oxidizing liquid and the volume of the spherical alumina carrier for impregnation. The impregnation time was 4 hours. The alumina 11 was modified with black phosphorus oxidizing liquid and roasted at 350°C for 2 hours under a N2 atmosphere. The catalyst Pd / HP-BP-Al2O3-11 was obtained after treatment by the comparative example of palladium loading.

[0047] According to Example 3, a black phosphorus oxidizing liquid modified alumina carrier and a palladium catalyst were prepared. The difference from Example 3 was that the black phosphorus oxidizing liquid was used to treat the alumina carrier by spraying with an atomizer. Anhydrous ethanol was added to the oxidizing liquid in a ratio of 2:1 between the volume of the black phosphorus oxidizing liquid and the volume of the spherical alumina carrier for spraying. The nozzle pressure was 0.2 MPa, the spraying temperature was 60°C, and after spraying, the black phosphorus oxidizing liquid modified alumina 12 was obtained after air drying at 160°C for 2 hours. The catalyst Pd / HP-BP-Al2O3-12 was obtained after treatment using the comparative example of palladium loading.

[0048] The palladium content of the catalyst samples in the comparative examples and examples was measured by ICP-AES and the results are shown in the following table:

[0049]

[0050] Catalyst hydrogen efficiency evaluation method: first use C9 aromatics and trioctyl phosphate to configure 2-ethyl anthraquinone to prepare a working solution (the solution containing anthraquinone is composed of 1,3,5-trimethylbenzene, trioctyl phosphate and 2-ethyl anthraquinone; the volume ratio of 1,3,5-trimethylbenzene to trioctyl phosphate is 75:25; the concentration of 1,3,5-trimethylbenzene is 660 mL / L; the concentration of trioctyl phosphate is 220 mL / L; the concentration of 2-ethyl anthraquinone is 120 g / L), 200 g of the catalyst is reduced in advance with hydrogen at 60 ° C and 0.2 MPa for 2 h, and then nitrogen is introduced to purge the fixed bed. After the purge is completed, hydrogen is introduced. After the air pressure stabilizes, the working solution is pumped in. After the flow rate stabilizes, the timing is started, and a sample is taken every 30 minutes for oxidation. The oxidation method is to take a certain amount of hydrogenated liquid after hydrogenation, add phosphoric acid, deionized water, and C9 aromatic hydrocarbons, and oxidize with oxygen. The oxidation reaction temperature is 65°C and the reaction pressure is 0.3 MPa. After oxidation five times, all the aqueous phases are collected and the amount of hydrogen peroxide produced is titrated using a standard potassium permanganate solution, and the hydrogen efficiency is obtained by calculation.

[0051]

Claims

1. A method for modifying a catalyst support with a black phosphorus oxidation liquid for industrial hydrogenation, characterized in that: The steps include: (1) The catalyst carrier should be dried before use; (2) using an oxidant solution to oxidize black phosphorus powder, i.e., a black phosphorus oxidizing solution, wherein the oxidant comprises one or more of potassium permanganate, hydrogen peroxide, sodium hypochlorite, peracetic acid, potassium dichromate, and sodium persulfate; the oxidant solution solvent is selected from one or more of water, ethanol, N-methylpyrrolidone, acetone, N,N-dimethylformamide, dimethyl sulfoxide, methanol, and isopropanol; the catalyst carrier is treated with the black phosphorus oxidizing solution by one or more of heating and refluxing under an inert atmosphere, impregnation and roasting in an inert atmosphere, and surface spraying; (3) The catalyst carrier is treated with black phosphorus oxidation liquid and then dried to obtain a black phosphorus modified carrier.

2. The method for modifying a catalyst support with a black phosphorus oxidation liquid for industrial hydrogenation according to claim 1, wherein: The catalyst carrier described in step (1) includes one or more of alumina, silica, carbon carrier, titanium dioxide, zirconium dioxide, phosphate, sulfate, molecular sieve, and hydrotalcite; the drying method is one or more of forced air drying, vacuum drying, or drying under an inert atmosphere; the drying temperature is 100°C-200°C, and the drying time is 2h-8h.

3. The method for modifying a catalyst support with a black phosphorus oxidation liquid for industrial hydrogenation according to claim 1, wherein: The black phosphorus powder in step (2) is prepared by mixing one or both of ball milling and air flow milling.

4. The method for modifying a catalyst support with a black phosphorus oxidation liquid for industrial hydrogenation according to claim 1, wherein: The mass ratio of the black phosphorus powder to the oxidant used in step (2) is 1:1-1:20, and the treatment time is 2-6 hours.

5. The method for modifying a catalyst support with a black phosphorus oxidation liquid for industrial hydrogenation according to claim 1, wherein: The mass ratio of the catalyst carrier to the black phosphorus oxidation liquid in step (2) is 10:1-1000:

1.

6. The method for modifying a catalyst support with a black phosphorus oxidation liquid for industrial hydrogenation according to claim 1, wherein: The reflux temperature of the heating reflux under the inert atmosphere in step (2) is 60°C-180°C, the reflux time is 10-40h, and the inert atmosphere is any one of N2, Ar or a mixed gas; The impregnation method in the inert atmosphere impregnation roasting is one of equal volume impregnation or supersaturated impregnation, the impregnation time is 0.5-4h, the roasting temperature is 200℃-350℃, the roasting time is 2-12h, and the inert atmosphere is any one of N2, Ar or a mixed gas; The surface spraying is carried out using an atomizer or a spray tower, the nozzle pressure is 0.05-0.2MPa, the spraying temperature is 20°C-60°C, and the ratio of the liquid volume used for spraying to the alumina carrier stack volume is 1:1-2:

1.

7. The method for modifying a catalyst support with a black phosphorus oxidation liquid for industrial hydrogenation according to claim 1, wherein: The drying method in step (3) is one or more of forced air drying, vacuum drying or drying under an inert atmosphere; the drying temperature is 60°C-160°C, and the drying time is 2h-12h.

8. A black phosphorus oxidation liquid modified catalyst carrier prepared by the method according to any one of claims 1 to 7.

9. An industrial hydrogenation process, characterized in that: A catalyst carrier modified with a black phosphorus oxidation liquid prepared by the method according to any one of claims 1 to 7; Black phosphorus oxidation liquid modified catalyst carrier loaded with precious metal active components is used in industrial hydrogenation process.

Images