Synthesis method of ortho-bimetal monatomic catalyst
Through the selective coordination of characteristic coordination groups and high-temperature carbon conversion methods, the stability and density of bimetallic single atom catalysts in traditional synthesis methods are solved, and the construction of high-density bimetallic single atom catalysts is realized, which has improved its Application potential in the fields of electrocatalysis, photocatalysis and biological diagnosis and treatment.
Patent Information
- Application Number
- CN202411288078.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-14
- Publication Date
- 2024-12-20
AI Technical Summary
It is difficult for the prior art to achieve stable construction of high-density ortho-bimetal single-atom catalysts. Traditional synthesis methods often lead to local metals in situ disorder and lose the intrinsic advantages of bimetal single-atom catalysts.
Ortho-bimetallic phthalocyanine template is synthesized through selective coordination of characteristic coordination groups, and its in-situ domain is confined to a carbon carrier for high-temperature in-situ carbon conversion, inhibiting the migration and agglomeration of metal atoms, forming high-density bisexual Metal single atom catalyst.
The synthesis of high-density, controllable bimetallic single-atom catalysts has been achieved, with wide application prospects in the fields of electrocatalysis, photocatalysis and biological diagnosis and treatment, and has improved catalytic activity and selectivity.
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Figure CN119158576A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of material synthesis, and in particular to a method for synthesizing an ortho-bimetallic single-atom catalyst. Background Art
[0002] Ortho bimetallic single atom catalysis has higher metal supports, atomic utilization, and more unsaturated coordination environments than single active center single atom catalysts. At the same time, the interaction between adjacent atoms can further optimize the adsorption and desorption process of the reactants, which is expected to further improve the catalytic activity and selectivity. In recent years, it has also become a research focus in the field of catalysis. In addition, bimetallic single atom catalysts can provide a rich combination of atomic sites and have broad application prospects. Therefore, the controllable construction of ortho bimetallic single atom catalysts is considered to be the next breakthrough in the field of single atom catalysts.
[0003] However, the high surface energy of metal single atoms makes it very easy for them to agglomerate during synthesis, resulting in ready-made nanoparticles or small clusters, which lose the intrinsic advantages of single atom catalysts. On the other hand, different metal atoms have different intrinsic properties, making it difficult to stably anchor two different metal atoms on a single carrier. At present, some synthesis methods of bimetallic single atom catalysts have also been reported, such as sequential deposition method, atomic layer deposition method, thermal migration method, etc. Bimetallic single atom catalysts synthesized by traditional synthesis strategies often only have localized metal in situ in the ortho state, and the whole is still in a disordered chaotic state, and the intrinsic advantages of ortho bimetallic single atoms are not brought into play. Therefore, it is urgent to develop new synthesis strategies for bimetallic single atom catalysts to achieve high-density ortho bimetallic single atom catalysts. Summary of the invention
[0004] In order to solve the above technical problems existing in the prior art, the purpose of the present invention is to provide a method for synthesizing an vicinal bimetallic single atom catalyst.
[0005] The technical solution adopted by the present invention to achieve the technical purpose is:
[0006] A method for synthesizing an ortho-bimetallic single-atom catalyst comprises:
[0007] (1) Selectively coordinate and synthesize ortho-bimetallic phthalocyanine templates through characteristic coordination groups;
[0008] (2) The ortho-bimetallic phthalocyanine template is in situ confined in a carbon support, and then in situ carbon conversion is performed to obtain an ortho-bimetallic single atom catalyst.
[0009] Preferably, in step (1), the characteristic coordination groups include but are not limited to -OH, -F, -COOH, and -NH2. Two groups capable of selective coordination can be selected according to actual needs.
[0010] Preferably, in step (1), the metal comprises non-noble metal and noble metal. Considering the relatively high cost of noble metal, non-noble metal is more preferred, but the synthesis method of the present application can be used for noble metal.
[0011] Furthermore, step (1) further comprises the following steps:
[0012] 1-1) Synthesizing metal phthalocyanine materials with characteristic coordination groups;
[0013] 1-2) The characteristic coordination groups with selective coordination ability are combined to synthesize the bimetallic ortho-phthalocyanine materials. The ortho-position formation mode is the selective coordination between local groups to form a specific bimetallic atom pairing form.
[0014] Preferably, in step (2), the temperature of carbon conversion is 700 to 1100 degrees Celsius.
[0015] More preferably, in step (2), the carbon conversion time is 30 to 240 minutes.
[0016] The ortho-bimetallic phthalocyanine template is in-situ confined in a carbon support. During the pyrolysis process, the phthalocyanine template confined in the carbon support is in-situ carbonized. Due to the confinement effect, the migration and agglomeration of metal atoms are suppressed, thereby forming a bimetallic ortho-single atom material.
[0017] The present invention has at least the following beneficial effects:
[0018] (I) The present invention can realize the controllable preparation of high-density ortho-bimetallic single-atom catalysts covering non-noble metals and noble metals. The synthesis method is simple and repeatable, and can be extended to a variety of bimetallic coordination forms to realize the construction of ortho-bimetallic single-atom data.
[0019] (ii) The vicinal bimetallic single atom catalyst obtained by this synthesis method has good application prospects in the fields of electrocatalysis, photocatalysis, and biodiagnosis and treatment. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Figure 1 The figure is a synthetic flow chart of the ortho-bimetallic single-atom catalyst of the present invention.
[0021] Figure 2 This is the spherical aberration diagram of the CuNi-DSAC synthesized in Example 1 of the present invention.
[0022] Figure 3 Catalytic performance diagram of oxygen reduction reaction of CuNi-DSAC synthesized in Example 1 of the present invention. DETAILED DESCRIPTION
[0023] In order to make the purpose, features and advantages of the present invention more obvious and easy to understand, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention. The experimental methods used in the embodiments of the present invention are conventional methods unless otherwise specified. The materials, reagents, etc. used in the embodiments of the present invention can be obtained from commercial channels unless otherwise specified.
[0024] The present invention provides a method for synthesizing an ortho-bimetallic single-atom catalyst. First, an ortho-bimetallic phthalocyanine template having ortho-metal atom characteristics is synthesized by selective coordination of characteristic coordination groups. Subsequently, the bimetallic phthalocyanine template is in-situ confined in a carbon carrier, and then the ortho-bimetallic single-atom catalyst is obtained by high-temperature in-situ carbon conversion.
[0025] Among them, the "characteristic coordination group" can select two groups that can be selectively coordinated according to actual needs, and is not limited to the "-F" and "-OH" groups that are selectively coordinated in the following embodiments; the "carbon carrier" can be used as long as it can achieve in-situ confinement of the bimetallic phthalocyanine template, and this application does not make specific restrictions. In addition, based on the synthesis method proposed in this application, those skilled in the art can select different reagents and method steps to achieve it according to actual needs, and are not limited to the specific reagents and condition parameters used in the following embodiments.
[0026] Example 1: Preparation of CuNi ortho-bimetallic single-atom catalyst CuNi-DSAC I. Synthesis of CuNi ortho-bimetallic phthalocyanine template
[0027] i. Synthesis of -OH-coordinated Ni phthalocyanine (NiPc(OH)8)
[0028] Take an appropriate amount of NiPc(OCH3)8 and suspend it in 10mL of dichloromethane. Add 0.57mL of BBr3 to the system under nitrogen protection and stir at room temperature for 4 days. After the reaction is completed, slowly pour 10mL of deionized water into the system, collect the precipitate by centrifugation at 8000rpm, wash it with methanol by centrifugation 3 times, and dry the obtained product under vacuum overnight to obtain a dark green solid, namely NiPc(OH)8.
[0029] ii. Synthesis of CuNi ortho-bimetallic phthalocyanine (CuNiPc)
[0030] Take 17 mg C 32 CuF 16 N8 (perfluorophthalocyanine copper) and 17 mg NiPc(OH)8 were added to a heat-resistant glass tube, followed by 1 mL DMF and 0.2 mL C6H15 N, ultrasonicate the mixture for 2 minutes to make it uniformly dispersed. Degas the system through three freeze-degassing-thawing cycles, and seal the glass tube with a burner. React at 120°C for 3 days. The product is washed with tetrahydrofuran, then Soxhlet extracted with tetrahydrofuran as solvent for one day, and the obtained product is dried overnight under vacuum, and the obtained product is CuNiPc.
[0031] 2. Synthesis method of CuNi-DSAC
[0032] Weigh 1.314g of 2-methylimidazole and dissolve it in 10mL of methanol solution, named as liquid A. Weigh 1.14g of zinc nitrate and 20mg of CuNiPc and dissolve them in 30mL of methanol, named as liquid B. After ultrasonicating liquid B for 10 minutes, pour liquid B into liquid A and stir for 1 hour. Then transfer the mixed solution stirred for 1 hour to a 50mL autoclave and react at 120°C for 5 hours. After the autoclave is cooled to room temperature, wash it with DMF twice, wash it with methanol 3 times, and then dry it at 60°C overnight. The dried sample is placed in a tubular furnace under Ar atmosphere and pyrolyzed at 950°C for 2 hours to obtain the CuNi-DSAC catalyst.
[0033] The spherical aberration diagram of CuNi-DSAC catalyst is shown in Figure 2 As shown, pairs of metal atoms can be found at the orange-framed positions, which can be attributed to the controllable construction of CuNi bimetallic sites.
[0034] The catalytic performance of the prepared catalyst for oxygen reduction reaction was tested by cyclic voltammetry scanning in oxygen-saturated 0.1M KOH at a scan rate of 5mV / s and an electrode speed of 1600r / min using a three-electrode system. Figure 3 As shown, the prepared CuNi catalyst exhibits good catalytic performance for oxygen reduction reaction.
[0035] Example 2: Preparation of CuCo ortho-bimetallic single-atom catalyst CuCo-DSAC I. Synthesis of CuCo ortho-bimetallic phthalocyanine template
[0036] i. Synthesis of -OH-coordinated Co phthalocyanine (CoPc(OH)8)
[0037] Take an appropriate amount of CoPc(OCH3)8 and suspend it in 10mL of dichloromethane. Add 0.57mL of BBr3 to the system under nitrogen protection and stir at room temperature for 4 days. After the reaction is completed, slowly pour 10mL of deionized water into the system, collect the precipitate by centrifugation at 8000rpm, wash it with methanol by centrifugation 3 times, and dry the obtained product under vacuum overnight to obtain a dark green solid, namely CoPc(OH)8.
[0038] ii. Synthesis of CuCo ortho-bimetallic phthalocyanine (CuCoPc)
[0039] Take 17 mg C 32 CuF 16 N8 and 17 mg CoPc(OH)8 were added to a heat-resistant glass tube, followed by 1 mL DMF and 0.2 mL C6H 15 N, ultrasonicate the mixture for 2 minutes to make it uniformly dispersed. Degas the system through three freeze-degassing-thawing cycles, and seal the glass tube with a burner. React at 120°C for 3 days. The product is washed with tetrahydrofuran, then Soxhlet extracted with tetrahydrofuran as solvent for one day, and the obtained product is dried overnight under vacuum, and the obtained product is CuNiPc.
[0040] 2. Synthesis of CuCo-DSAC
[0041] Weigh 1.314g of 2-methylimidazole and dissolve it in 10mL of methanol solution, named liquid A. Weigh 1.14g of zinc nitrate and 20mg of CuCoPc and dissolve them in 30mL of methanol, named liquid B. After ultrasonicating liquid B for 10 minutes, pour liquid B into liquid A and stir for 1 hour. Then transfer the mixed solution that has been stirred for 1 hour to a 50mL high-pressure reactor and react at 120°C for 5 hours. After the high-pressure reactor cools to room temperature, wash it with DMF 2 times, methanol 3 times, and then dry it at 60°C overnight. The dried sample is placed in a tubular furnace under Ar atmosphere and pyrolyzed at 950°C for 2 hours to obtain a CuCo-DSAC catalyst. Example 3: Preparation of CuFe ortho-bimetallic single-atom catalyst CuFe-DSAC 1. Synthesis method of CuFe ortho-bimetallic phthalocyanine template
[0042] i. Synthesis of -OH-coordinated Fe phthalocyanine (FePc(OH)8)
[0043] Take an appropriate amount of FePc(OCH3)8 and suspend it in 10mL of dichloromethane. Add 0.57mL of BBr3 to the system under nitrogen protection and stir at room temperature for 4 days. After the reaction is completed, slowly pour 10mL of deionized water into the system, collect the precipitate by centrifugation at 8000rpm, wash it with methanol by centrifugation 3 times, and dry the obtained product under vacuum overnight to obtain a dark green solid, which is FePc(OH)8.
[0044] ii. Synthesis of CuFe ortho-bimetallic phthalocyanine (CuFePc)
[0045] Take 17 mg C 32 CuF 16 N8 and 17 mg FePc(OH)8 were added to a heat-resistant glass tube, followed by 1 mL DMF and 0.2 mL C6H 15N, ultrasonicate the mixture for 2 minutes to make it uniformly dispersed. Degas the system through three freeze-degassing-thawing cycles, and seal the glass tube with a burner. React at 120°C for 3 days. The product is washed with tetrahydrofuran, then Soxhlet extracted with tetrahydrofuran as solvent for one day, and the obtained product is dried overnight under vacuum, and the obtained product is CuFePc.
[0046] 2. Synthesis of CuFe-DSAC
[0047] Weigh 1.314g of 2-methylimidazole and dissolve it in 10mL of methanol solution, named as liquid A. Weigh 1.14g of zinc nitrate and 20mg of CuFePc and dissolve them in 30mL of methanol, named as liquid B. After ultrasonicating liquid B for 10 minutes, pour liquid B into liquid A and stir for 1 hour. Then transfer the mixed solution stirred for 1 hour to a 50mL autoclave and react at 120°C for 5 hours. After the autoclave is cooled to room temperature, wash it with DMF twice, wash it with methanol 3 times, and then dry it at 60°C overnight. The dried sample is placed in a tubular furnace under Ar atmosphere and pyrolyzed at 950°C for 2 hours to obtain the CuFe-DSAC catalyst.
[0048] Obviously, the above embodiments of the present invention are merely examples to more clearly illustrate the present invention, and are not limitations on the implementation methods of the present invention. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made on the basis of the above description. It is impossible to list all the implementation methods here. All obvious changes or modifications derived from the technical solution of the present invention are still within the protection scope of the present invention.
Claims
1. A method for synthesizing an ortho-bimetallic single-atom catalyst, comprising: (1) Selectively coordinate and synthesize ortho-bimetallic phthalocyanine templates through characteristic coordination groups; (2) The ortho-bimetallic phthalocyanine template is in situ confined in a carbon support, and then in situ carbon conversion is performed to obtain an ortho-bimetallic single atom catalyst.
2. The synthesis method according to claim 1, characterized in that In step (1), the characteristic coordinating groups include -OH, -F, -COOH, and -NH2.
3. The synthesis method according to claim 1, characterized in that In step (1), the metal comprises non-noble metal and noble metal.
4. The synthesis method according to claim 1, characterized in that Step (1) further comprises the following steps: 1-1) Synthesizing metal phthalocyanine materials with characteristic coordination groups; 1-2) The characteristic coordination groups with selective coordination ability are combined to synthesize the bimetallic ortho-phthalocyanine materials. The ortho-position formation mode is the selective coordination between local groups to form a specific bimetallic atomic pairing form.
5. The synthesis method according to claim 1, characterized in that In step (2), the temperature of carbon conversion is 700 to 1100 degrees Celsius.
6. The synthesis method according to claim 5, characterized in that In step (2), the carbon conversion time is 30 to 240 minutes.