A 1 Process for the preparation of a boron nitride-based monatomic catalyst for the selective production of O2

Abstract

The application discloses a preparation method of a catalyst, in particular to a universal preparation method of a boron nitride-based monatomic catalyst capable of realizing 1 O2 selective generation. The application is based on a boron nitride vacancy regulation and metal anchoring strategy, and constructs a boron nitride loaded metal monatomic catalyst. The application has the advantages that the strategy is universal to the preparation of different metal monatomic catalysts, including cobalt, iron, copper, nickel and manganese, and the prepared catalysts can realize 1 O2 efficient generation, and provides a new strategy for the preparation of a catalyst capable of realizing 1 O2 regulated generation.

Description

Technical Field

[0001] This invention relates to a method for preparing a catalyst, specifically a method that can achieve... 1 A universal preparation method for boron nitride-based single-atom catalysts selectively generated from O2 belongs to the field of advanced oxidation catalysis technology. Background Technology

[0002] Reactive oxygen species (ROS) are a class of chemically reactive molecules or ions with high oxidizing power, holding significant research value in environmental protection, organic synthesis, and life sciences. Currently, ROS generation methods mainly include photoelectrocatalytic reactions, enzymatic reactions in biological systems, and PMS activation reactions. Among these, the PMS-assisted ROS generation pathway has attracted widespread attention due to its high ROS generation rate and the absence of external conditions. However, in the PMS activation system, multiple ROS can coexist, which can have adverse effects in certain applications. For example, singlet oxygen (… 1 O2) and superoxide radicals (O2) ·- As a mild reactive oxygen species (ROS), it can selectively oxidize organic compounds (such as sulfides and alcohols) and induce apoptosis in cancer cells during cell therapy. However, it also has its own coexisting... · OH is a dangerous reactive oxygen species (ROS) that can lead to excessive oxidation of substrates in organic synthesis or disrupt the intracellular antioxidant balance, causing irreparable damage to healthy cells. Therefore, it is necessary to conduct exploratory research on the selective generation of ROS by activated PMS.

[0003] The main reasons why ROS cannot be generated selectively in the PMS system can be attributed to two points: the diversity of catalyst active sites and the complexity of PMS activation pathway. The interaction between these two factors increases the reaction pathway of PMS, leading to the simultaneous generation of multiple ROS. In recent years, related reports have found that by constructing catalysts with uniform active sites and structures, side reactions in PMS activation can be avoided, and the selective generation of ROS can be effectively achieved. For example, according to the literature [1], by loading metallic iron single atoms on carbon nitride matrix materials through pyrolysis, uniform Fe-N4 sites are formed and used to activate peroxy-sulfate, which can achieve the desired effect. 1 Highly selective O2 generation. [1] Zhang L, Jiang X, Zhong Z, et al. Carbon nitride supported high loading Fe single atom catalyst for activating of peroxymonosulfate to generate 1O2 with 100% selectivity[J].Angewandte Chemie,2021. According to reference [2], a cobalt-doped carbon-supported single-atom catalyst was prepared by one-step pyrolysis of MOF material. The homogeneous CoN obtained by this method 2+2 Sites can also be achieved 1 O2 is generated with high selectivity. [2] Mi, Xueyue, Wang, Pengfei, Xu, Shizhe Su, et al. almost 100% peroxymonosulfate conversion to singletoxygen on single-Atom CoN 2+2 Sites[J].Angewandte Chemie,2021,60(9). However, catalysts prepared by pyrolysis have inherent drawbacks, namely, the preparation conditions are harsh and it is difficult to achieve universal preparation. Therefore, it is still necessary to develop a universal and convenient strategy. Summary of the Invention

[0004] Based on the above ideas, this invention proposes a method that can achieve... 1 A universal method for preparing O2-selectively generated boron nitride-based single-atom catalysts is presented. This universal preparation strategy is based on boron nitride vacancy regulation, achieved through metal anchoring at the vacancy sites. This process does not require pyrolysis, avoiding the performance differences caused by the uncontrollable local structure of the catalyst during pyrolysis. The synthesized supported boron nitride-based catalyst has defined active sites and a uniform structure, which can be used to regulate the activation of peroxide oxidants, achieving... 1 O2 is generated with high selectivity.

[0005] A sort of 1 The method for preparing a boron nitride-based single-atom catalyst selectively generated by O2 includes the following steps:

[0006] (1) Preparation of boron nitride: Using nitrogen-containing substances as nitrogen source, boron-containing substances as boron source, and zinc salt as vacancy auxiliary agent, boron nitride with vacancy is prepared by high-temperature calcination.

[0007] (2) Metal loading: Take a small amount of the boron nitride material synthesized in step (1), disperse it in a metal salt solution, and adsorb metal ions by impregnation to form a coordination structure. The boron nitride-based catalyst with metal loading can then be obtained.

[0008] (3) Catalyst-driven 1 O2 generation usage method: Take a small amount of boron nitride-based catalyst from step (2) and disperse it in a solution containing peroxide to carry out the reaction, driving the reaction. 1The generation of O2 was analyzed and detected by chemical probe method and EPR analysis of the system. 1 O2.

[0009] Preferably, the boron source required for the preparation of the boron nitride-based catalyst in step (1) is one or more of diborane, boron chloride, boron sulfide, boric acid, boron oxide, borax, ammonium tetrafluoroborate, boronamane, and sodium borohydride, and the nitrogen source required is one or more of melamine, urea, cyanuric acid, sodium azide, dicyandiamide, and sodium amino acid, and the mass ratio of boron source to nitrogen source is 1:0.1-10.

[0010] Preferably, the vacancy auxiliaries required for the preparation of the boron nitride-based catalyst in step (1) are one or more of zinc hydroxide, zinc oxide, zinc chloride, zinc acetate, zinc nitrate, or zinc sulfate.

[0011] Preferably, the calcination temperature for preparing the boron nitride-based catalyst in step (1) is 450-1200℃, and the annealing time is 2-12h. The boron nitride material has boron vacancies and more edge nitrogen atoms.

[0012] Preferably, the metal salt required for the preparation of the boron nitride-based catalyst in step (2) is one or more of cobalt nitrate, ferric nitrate, copper nitrate, zinc nitrate, manganese nitrate, cobalt sulfate, ferric sulfate, copper sulfate, zinc sulfate, or manganese sulfate.

[0013] Preferably, the impregnation method used in step (2) for preparing the boron nitride-based catalyst involves dispersing boron nitride material in a solution to adsorb metal ions, and forming coordination through the anchoring effect between nitrogen and metal ions to obtain a catalyst with a single-atom structure.

[0014] Preferably, the impregnation temperature of the impregnation method used in step (2) for preparing the boron nitride-based catalyst is 30-80℃ and the impregnation time is 1-20h.

[0015] Preferably, the peroxide in step (3) is one or more of peroxymonosulfate, peroxydisulfate, or hydrogen peroxide. The concentration is 0.1-5 mol / L.

[0016] Preferably, the reaction conditions in step (3) are: temperature at room temperature (15-35°C), pressure at atmospheric pressure, and pH between 6 and 9.

[0017] The beneficial effects of this invention are:

[0018] (1) The preparation method can achieve loading of different metals based on boron nitride vacancy regulation and metal anchoring strategy, avoiding the problems of difficult structure control and harsh reaction conditions during catalyst pyrolysis.

[0019] (2) The catalyst prepared by this method has definite active sites and a uniform structure, which can achieve highly efficient activation and selective generation of peroxides. 1 The purpose of O2 also provides ideas for the application of Fenton-like systems in other fields. Attached Figure Description

[0020] Figure 1 This is a structural characterization diagram of a single cobalt atom supported on a vacant boron nitride in this invention.

[0021] Figure 2 This invention generates boron nitride-supported cobalt single-atom activated persulfate. 1 EPR spectrum of O2.

[0022] Figure 3 This invention generates boron nitride-supported cobalt single-atom activated persulfate. 1 Diagram of O2 detection using the DPA chemical probe. Detailed Implementation

[0023] The present invention will be further illustrated below with specific examples. These embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0024] Example 1:

[0025] (1) Preparation of boron nitride: 0.30 mol urea, 0.01 mol boric acid and 0.00027 mol zinc acetate were mixed and stirred. The mixture was then dissolved in a beaker containing a 1:1 mixture of ethanol and deionized water. The mixture was stirred at 45 °C for about 12 h until dry to obtain a white solid. The solid was then transferred to a mortar and ground thoroughly to obtain a powder. Finally, the powder was calcined in a tube furnace at 1200 °C for 2 h and allowed to cool naturally to room temperature to obtain vacant boron nitride.

[0026] (2) Metal loading: Take 30 mg of boron nitride material synthesized in step (1), ultrasonically disperse it in 30 mL of anhydrous ethanol, add 0.01 mol of cobalt chloride hexahydrate, stir at 60 °C for 12 h, and then filter and dry to obtain boron nitride supported cobalt single-atom catalyst.

[0027] (3) Catalyst-driven 1 O2 generation method: Take 2 mg of the catalyst obtained in step (2) and disperse it in 20 mL of 0.05 mmol persulfate solution to carry out the reaction, and detect the generation of ROS.

[0028] Experimental results showed that the system generated 1 The proportion of O2 can reach 98%, and the concentration is 67.7 μM after 10 minutes of reaction. Figure 1 This is a structural characterization diagram of a single cobalt atom supported on a vacant boron nitride in this embodiment; Figure 2 This invention generates boron nitride-supported cobalt single-atom activated persulfate. 1 EPR spectrum of O2; Figure 3 This invention generates boron nitride-supported cobalt single-atom activated persulfate. 1 Diagram of O2 detection using the DPA chemical probe.

[0029] Example 2:

[0030] (1) Preparation of boron nitride: 0.30 mol urea, 0.01 mol boric acid and 0.00027 mol zinc acetate were mixed and stirred. The mixture was then dissolved in a beaker containing a 1:1 mixture of ethanol and deionized water. The mixture was stirred at 45 °C for about 12 h until dry to obtain a white solid. The solid was then transferred to a mortar and ground thoroughly to obtain a powder. Finally, the powder was calcined in a tube furnace at 1200 °C for 2 h and allowed to cool naturally to room temperature to obtain vacant boron nitride.

[0031] (2) Metal loading: Take 30 mg of boron nitride material synthesized in step (1), ultrasonically disperse it in 30 mL of anhydrous ethanol, add 0.01 mol of copper chloride hexahydrate, stir at 60 °C for 12 h, and then filter and dry to obtain boron nitride supported copper single-atom catalyst.

[0032] (3) Catalyst-driven 1 O2 generation method: Take 2 mg of the catalyst obtained in step (2) and disperse it in 20 mL of 0.05 mmol persulfate solution to carry out the reaction, and detect the generation of ROS.

[0033] Experimental results showed that the system generated 1 The proportion of O2 can reach 98%, and the concentration is 23.4 μM after 10 minutes of reaction.

[0034] Example 3:

[0035] (1) Preparation of boron nitride: 0.30 mol urea, 0.01 mol boric acid and 0.00027 mol zinc acetate were mixed and stirred. The mixture was then dissolved in a beaker containing a 1:1 mixture of ethanol and deionized water. The mixture was stirred at 45 °C for about 12 h until dry to obtain a white solid. The solid was then transferred to a mortar and ground thoroughly to obtain a powder. Finally, the powder was calcined in a tube furnace at 1200 °C for 2 h and allowed to cool naturally to room temperature to obtain vacant boron nitride.

[0036] (2) Metal loading: Take 30 mg of boron nitride material synthesized in step (1), ultrasonically disperse it in 30 mL of anhydrous ethanol, add 0.01 mol of manganese chloride tetrahydrate, stir at 60 °C for 12 h, and then filter and dry to obtain boron nitride supported manganese single-atom catalyst.

[0037] (3) Catalyst-driven 1 O2 generation method: Take 2 mg of the catalyst obtained in step (2) and disperse it in 20 mL of 0.05 mmol persulfate solution to carry out the reaction, and detect the generation of ROS.

[0038] Experimental results showed that the system generated 1 The proportion of O2 can reach 98%, and the concentration is 23.7 μM after 10 minutes of reaction.

[0039] Example 4:

[0040] (1) Preparation of boron nitride: 0.30 mol urea, 0.01 mol boric acid and 0.00027 mol zinc acetate were mixed and stirred. The mixture was then dissolved in a beaker containing a 1:1 mixture of ethanol and deionized water. The mixture was stirred at 45 °C for about 12 h until dry to obtain a white solid. The solid was then transferred to a mortar and ground thoroughly to obtain a powder. Finally, the powder was calcined in a tube furnace at 1200 °C for 2 h and allowed to cool naturally to room temperature to obtain vacant boron nitride.

[0041] (2) Metal loading: Take 30 mg of boron nitride material synthesized in step (1), ultrasonically disperse it in 30 mL of anhydrous ethanol, add 0.01 mol of nickel chloride hexahydrate, stir at 60 °C for 12 h, and then filter and dry to obtain boron nitride-supported nickel single-atom catalyst.

[0042] (3) Catalyst-driven 1 O2 generation method: Take 2 mg of the catalyst obtained in step (2) and disperse it in 20 mL of 0.05 mmol persulfate solution to carry out the reaction, and detect the generation of ROS.

[0043] Experimental results showed that the system generated 1 The proportion of O2 can reach 98%, and the concentration after 10 minutes of reaction is 27.7 μM.

[0044] Example 5:

[0045] (1) Preparation of boron nitride: 0.30 mol urea, 0.01 mol boric acid and 0.00027 mol zinc acetate were mixed and stirred. The mixture was then dissolved in a beaker containing a 1:1 mixture of ethanol and deionized water. The mixture was stirred at 45 °C for about 12 h until dry to obtain a white solid. The solid was then transferred to a mortar and ground thoroughly to obtain a powder. Finally, the powder was calcined in a tube furnace at 1200 °C for 2 h and allowed to cool naturally to room temperature to obtain vacant boron nitride.

[0046] (2) Metal loading: Take 30 mg of boron nitride material synthesized in step (1), ultrasonically disperse it in 30 mL of anhydrous ethanol, add 0.01 mol of ferric chloride hexahydrate, stir at 60 °C for 12 h, and then filter and dry to obtain boron nitride supported iron single-atom catalyst.

[0047] (3) Catalyst-driven 1 Method for using O2 generation: Take 2 mg of the catalyst obtained in step 2) and disperse it in 20 mL of 0.5 mmol persulfate solution to carry out the reaction, and detect the generation of ROS.

[0048] Experimental results showed that the system generated 1 The proportion of O2 can reach 97%, and the concentration is 97.7 μM after 10 minutes of reaction.

[0049] Example 6:

[0050] (1) Preparation of boron nitride: 0.30 mol urea, 0.01 mol boric acid and 0.00027 mol zinc acetate were mixed and stirred. The mixture was then dissolved in a beaker containing a 1:1 mixture of ethanol and deionized water. The mixture was stirred at 45 °C for about 12 h until dry to obtain a white solid. The solid was then transferred to a mortar and ground thoroughly to obtain a powder. Finally, the powder was calcined in a tube furnace at 1000 °C for 2 h and allowed to cool naturally to room temperature to obtain vacant boron nitride.

[0051] (2) Metal loading: Take 30 mg of boron nitride material synthesized in step (1), ultrasonically disperse it in 30 mL of anhydrous ethanol, add 0.01 mol of cobalt chloride hexahydrate, stir at 60 °C for 12 h, and then filter and dry to obtain boron nitride supported cobalt single-atom catalyst.

[0052] (3) Catalyst-driven 1 O2 generation method: Take 2 mg of the catalyst obtained in step (2) and disperse it in 20 mL of 0.3 mmol persulfate solution to carry out the reaction, and detect the generation of ROS.

[0053] Experimental results showed that the system generated 1The proportion of O2 can reach 98%, and the concentration is 97.7 μM after 10 minutes of reaction.

[0054] Example 7:

[0055] (1) Preparation of boron nitride: 0.30 mol urea, 0.01 mol boric acid and 0.00027 mol zinc acetate were mixed and stirred. The mixture was then dissolved in a beaker containing a 1:1 mixture of ethanol and deionized water. The mixture was stirred at 45 °C for about 12 h until dry to obtain a white solid. The solid was then transferred to a mortar and ground thoroughly to obtain a powder. Finally, the powder was calcined in a tube furnace at 1200 °C for 2 h and allowed to cool naturally to room temperature to obtain vacant boron nitride.

[0056] (2) Metal loading: Take 30 mg of boron nitride material synthesized in step (1), ultrasonically disperse it in 30 mL of anhydrous ethanol, add 0.01 mol of cobalt chloride hexahydrate, stir at 75 °C for 12 h, and then filter and dry to obtain boron nitride supported cobalt single-atom catalyst.

[0057] (3) Catalyst-driven 1 O2 generation method: Take 2 mg of the catalyst obtained in step (2) and disperse it in 20 mL of 0.2 mmol persulfate solution to carry out the reaction, and detect the generation of ROS.

[0058] Experimental results showed that the system generated 1 The proportion of O2 can reach 98%, and the concentration is 87.2 μM after 20 minutes of reaction.

[0059] Example 8:

[0060] (1) Preparation of boron nitride: 0.30 mol urea, 0.01 mol boric acid and 0.00027 mol zinc acetate were mixed and stirred. The mixture was then dissolved in a beaker containing a 1:1 mixture of ethanol and deionized water. The mixture was stirred at 45 °C for about 12 h until dry to obtain a white solid. The solid was then transferred to a mortar and ground thoroughly to obtain a powder. Finally, the powder was calcined in a tube furnace at 1000 °C for 2 h and allowed to cool naturally to room temperature to obtain vacant boron nitride.

[0061] (2) Metal loading: Take 30 mg of boron nitride material synthesized in step (1), ultrasonically disperse it in 30 mL of anhydrous ethanol, add 0.01 mol of cobalt chloride hexahydrate, stir at 75 °C for 12 h, and then filter and dry to obtain boron nitride supported cobalt single-atom catalyst.

[0062] (3) Catalyst-driven 1O2 generation method: Take 2 mg of the catalyst obtained in step (2) and disperse it in 20 mL of 0.1 mmol persulfate solution to carry out the reaction, and detect the generation of ROS.

[0063] Experimental results showed that the system generated 1 The proportion of O2 can reach 98%, and the concentration is 47.9 μM after 10 minutes of reaction.

[0064] Comparative Example 1:

[0065] (1) Preparation of boron nitride: 0.30 mol urea, 0.01 mol boric acid and 0.00027 mol zinc acetate were mixed and stirred. The mixture was then dissolved in a beaker containing a 1:1 mixture of ethanol and deionized water. The mixture was stirred at 45 °C for about 12 h until dry to obtain a white solid. The solid was then transferred to a mortar and ground thoroughly to obtain a powder. Finally, the powder was calcined in a tube furnace at 1200 °C for 2 h and allowed to cool naturally to room temperature to obtain vacant boron nitride.

[0066] (2) Metal loading: Take 30 mg of boron nitride material synthesized in step (1), ultrasonically disperse it in 30 mL of anhydrous ethanol, add 0.01 mol of cobalt chloride hexahydrate, stir at 60 °C for 12 h, and then filter and dry to obtain boron nitride supported cobalt single-atom catalyst.

[0067] (3) Catalyst-driven 1 O2 generation method: Take 2 mg of the catalyst obtained in step (2) and disperse it in 20 mL of aqueous solution for reaction, and detect the generation of ROS.

[0068] Experimental results showed that this system could not generate 1 O2 indicates that the addition of PMS generates 1 The key to O2. Comparative Example 2:

[0069] (1) Preparation of boron nitride: 0.30 mol urea, 0.01 mol boric acid and 0.00027 mol zinc acetate were mixed and stirred. The mixture was then dissolved in a beaker containing a 1:1 mixture of ethanol and deionized water. The mixture was stirred at 45 °C for about 12 h until dry to obtain a white solid. The solid was then transferred to a mortar and ground thoroughly to obtain a powder. Finally, the powder was calcined in a tube furnace at 1200 °C for 2 h and allowed to cool naturally to room temperature to obtain vacant boron nitride.

[0070] (2) Application in selective ROS generation: Take 2 mg of vacant boron nitride obtained in step (1) and disperse it in 20 mL of 0.05 mmol persulfate solution to carry out the reaction and detect the generation of ROS.

[0071] Experimental results showed that the system generated 1 The low O2 generation indicates that the loading of metal on boron nitride activates PMS generation. 1 The key to O2.

[0072] Comparative Example 3:

[0073] (1) Catalyst-driven 1 Method for using O2 generation: Add 0.01 mol cobalt chloride hexahydrate and disperse it in 20 mL of 0.05 mmol persulfate solution to carry out the reaction, and detect the generation of ROS.

[0074] Experimental results showed that almost no [something] could be detected in homogeneous systems. 1 O2 indicates that homogeneous cobalt ions cannot achieve the desired effect in the PMS system. 1 Efficient generation of O2.

[0075] Comparative Example 4:

[0076] A 20 mL solution of 0.1 mmol of persulfate was taken, and the ROS formation was measured. The results showed that without a catalyst, ROS formation was minimal. 1 O2.

Claims

1. A kind 1 The application of boron nitride-based single-atom catalysts selectively generated from O2 is characterized by... The catalyst preparation method includes the following steps: (1) Preparation of vacant boron nitride: Using a nitrogen-containing substance as the nitrogen source, a boron-containing substance as the boron source, and a zinc salt as the vacancy auxiliary, boron nitride with vacancy sites is prepared by high-temperature calcination; the boron source required for the preparation of the boron nitride-based single-atom catalyst is one or more of diborane, boron chloride, boron sulfide, boric acid, boron oxide, borax, ammonium tetrafluoroborate, boronamane, or sodium borohydride, and the nitrogen source required is one or more of melamine, urea, cyanuric acid, sodium azide, dicyandiamide, or sodium amide, and the mass ratio of boron source to nitrogen source is 1:0.1-10; the vacancy auxiliary required for the preparation of the boron nitride-based single-atom catalyst is one or more of zinc hydroxide, zinc oxide, zinc chloride, zinc acetate, zinc nitrate, or zinc sulfate; the calcination temperature required for the preparation of the boron nitride-based single-atom catalyst is 450-1200 ℃, and the annealing time is 2-12h; (2) Loading of metal single atoms: Take a small amount of boron nitride synthesized in step (1), disperse it in a metal salt solution, and adsorb metal ions by impregnation to form a coordination structure; thus, a boron nitride-based single-atom catalyst loaded with metal can be obtained; the metal salt required for the preparation of the boron nitride-based single-atom catalyst is one or more of cobalt nitrate, ferric nitrate, copper nitrate, zinc nitrate, manganese nitrate, cobalt sulfate, ferric sulfate, copper sulfate, zinc sulfate, or manganese sulfate; The application of catalysts includes the following steps: (3) Take a small amount of boron nitride-based single-atom catalyst from step (2) and disperse it in a solution containing one or more of hydrogen persulfate or hydrogen peroxide to carry out the reaction, driving the reaction. 1 The O2 can be generated to obtain it.

2. The one according to claim 1 1 The application of boron nitride-based single-atom catalysts selectively generated from O2 is characterized by... The impregnation method used in step (2) to prepare the boron nitride-based single-atom catalyst involves dispersing boron nitride material in a solution to adsorb metal ions, and forming coordination through the anchoring effect between nitrogen and metal ions to obtain a catalyst with a single-atom structure.

3. The one according to claim 1 1 The application of boron nitride-based single-atom catalysts selectively generated from O2 is characterized by... The impregnation temperature for the boron nitride-based single-atom catalyst prepared in step (2) is 30-80 °C, and the impregnation time is 1-20 h.

4. The one according to claim 1 1 The application of boron nitride-based single-atom catalysts selectively generated from O2 is characterized by... The concentration of the solution in step (3) is 0.1-5 mol / L.

5. The one according to claim 1 1 The application of boron nitride-based single-atom catalysts selectively generated from O2 is characterized by... The reaction conditions described in step (3) are: temperature at room temperature (15-35 °C), pressure at atmospheric pressure, and pH between 6 and 9.

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