Monosaccharide-induced regulation of chiral platinum-based alloy nanohelix catalysts, and preparation method and application thereof
Patent Information
- Application Number
- CN202610726910.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-05-25
- Publication Date
- 2026-09-22
AI Technical Summary
[0004]上述工作虽然揭示了通过各类手性分子对纳米晶体手性材料合成调控的可能性,但是仍然存在以下两个主要问题：1、目前报导的手性金属纳米材料主要集中于以金、银为代表的具有表面等离激元共振（SPR）效应的贵金属，虽然它们具有突出的手性光学方面的应用前景，但是在手性催化方面的性能较差
[0018]有益效果：本发明将金属盐前驱体与表面活性剂（CTAB）溶于油胺溶剂中，以某一类型的手性单糖作为手性诱导剂，通过贵金属/非贵金属的特定原子比例组成，以及反应的温度、时间、升温速率的控制，利用单糖的手性旋光性与使用量，成功精确地调控铂基合金纳米螺旋线的手性旋向与螺距等手性形貌特征，反应条件温和、操作简单。
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Figure CN122787035A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of chiral catalyst technology, specifically relating to a monosaccharide-induced chiral platinum-based alloy nanospiral catalyst, its preparation method, and its application. Background Technology
[0002] Chiral science is closely related to various life science phenomena and significantly influences the physicochemical properties of materials. The development of chiral science at all levels has made outstanding contributions to the progress of human society. For example, at the molecular scale, chiral catalysts exhibit enantioselectivity in various important biochemical reactions, and at the nanoscale, chiral materials are widely used in optical displays, sensing, biodetection, and cellular immune responses, highlighting the importance of developing chiral science. Among these, fundamental research on the precise construction of chiral materials is of paramount importance, serving as the cornerstone of all chiral-related applications. However, current research on the synthesis of chiral materials still faces significant challenges, the most prominent being the lack of efficient and universally applicable methods and theoretical explanations for obtaining single mirror-image isomers in the synthesis of chiral materials.
[0003] Currently reported techniques for synthesizing chiral materials include chiral photolithography (Nat. Photon. 2011, 5, 523), chiral template methods (J. Am. Chem. Soc. 2022, 144, 1663), and chiral self-assembly (Nature 2022, 612, 259). While these methods have made significant progress, they still face challenges in simplifying operational procedures and achieving large-scale production. Furthermore, these methods lack universal theoretical guidance for material synthesis. In recent years, wet chemical solution synthesis has provided a wealth of flexibility and ease of operation for the synthesis of various nanocrystalline materials. Among these methods, inducing, growing, and controlling the chiral morphology of nanocrystals through chiral ligand molecules in solution has proven to be a highly effective method for synthesizing chiral materials, effectively transferring the molecular chirality of the induced ligand to the geometric chirality of the nanomaterial. For example, a series of chiral gold nanoparticles with abundant chiral crystal faces and broken mirror symmetry have been reported to be synthesized in chemical solutions through the induction and regulation of amino acids and peptides with single chiral centers, and have great potential applications in chiral optical imaging and signal amplification (Nature 2018, 556, 360; Nature 2022, 612, 470; Nat. Commun. 2022, 13, 5081); as another example, a series of chiral gold nanorods with surface chiral corrugations have been reported to be synthesized in a induced and regulated manner of chiral molecules such as 1,1'-bis(2-naphthol) and its derivative 1,1'-binaphthyl-2,2'-diamine, which have single axial chirality (Science 2020, 368, 1472).
[0004] While the aforementioned work reveals the possibility of controlling the synthesis of chiral nanocrystal materials through various chiral molecules, two main problems remain: 1. Currently reported chiral metal nanomaterials mainly focus on noble metals such as gold and silver, which exhibit surface plasmon resonance (SPR) effects. Although they have promising applications in chiral optics, their performance in chiral catalysis is relatively poor. Excellent chiral catalytic performance, including good catalytic activity and excellent enantiomeric selectivity, is another broad application area for chiral nanomaterials. For example, in the catalysis related to the recognition and resolution of chiral drugs, chiral drugs generally only have one configuration with therapeutic effect, while the other configuration may be ineffective or even harmful. For instance, 3,4-dihydroxy-L-phenylalanine (L-DOPA), a drug for treating Parkinson's disease, has good therapeutic effects, while its chiral enantiomer, 3,4-dihydroxy-D-phenylalanine (D-DOPA), causes a reduction in endogranulocytes. This illustrates the importance of chiral molecule recognition and catalysis. Therefore, there is an urgent need to develop a simple synthetic method to synthesize chiral noble metal nanomaterials with high catalytic activity, such as platinum and iridium, in order to effectively expand their application in the field of chiral catalysis. Secondly, most reported small-molecule chiral inducers focus on amino acids, especially sulfur-containing amino acids (e.g., cysteine, penicillamine, cystine), which have a single chiral atomic center. While these inducers are effective for the synthesis of chiral noble metal nanomaterials such as gold and silver, reports on the chiral-induced synthesis of noble metal nanomaterials of other elements are scarce. Furthermore, the introduction of sulfur can cause strong metal-sulfur (MS) interactions, thereby poisoning the catalyst surface and reducing catalytic performance. Therefore, it is also necessary to find and broaden other types of non-sulfur-containing small-molecule chiral inducers, such as small-molecule chiral inducers with multiple chiral atomic centers, such as chiral monosaccharides. In summary, there is an urgent need to invent a simple, controllable chiral property method for preparing platinum-based chiral nanomaterials with good chiral catalytic performance. Summary of the Invention
[0005] Technical Problem Solved: This invention provides a monosaccharide-induced chiral platinum-based alloy nanospiral catalyst, its preparation method, and its applications. The helix direction (right-handed or left-handed) of the chiral platinum-based alloy nanospiral can be controlled by adding enantiomers of chiral monosaccharides with different optical rotations to the reaction solution. Preliminary chiral catalytic performance studies show that the synthesized chiral nanospirals exhibit excellent catalytic selectivity for the selective oxidation of D / L-DOPA molecules. The synthesis method is simple and feasible, and holds promise for large-scale production.
[0006] On one hand, this invention provides a method for synthesizing platinum-based alloy chiral nanospires, including binary alloys of platinum-cobalt (PtCo) and platinum-nickel (PtNi) and ternary alloys of platinum-iridium-cobalt (PtIrCo) and platinum-cobalt-nickel (PtCoNi). The most pronounced chiral helical morphology is observed when the atomic ratio of noble metal components (Pt, Ir) is between 80% and 90% and that of non-noble metal components (Co, Ni) is between 10% and 20%. All platinum-based alloy nanospires possess a face-centered cubic (fcc) single-phase solid solution crystal structure, with non-noble metal elements uniformly distributed atomically within the material. The helix length is on the micrometer scale, with a diameter of approximately 15 to 20 nm and a pitch length of approximately 8 to 13 nm. The specific pitch length can be controlled during the synthesis process by adding the content of chiral monosaccharides.
[0007] On the other hand, the chiral direction (right-handed or left-handed) of the platinum-based alloy chiral nanospires in this invention is closely related to the optical activity (+ or −) of the chiral monosaccharides added during the synthesis process. All monosaccharides with positive optical activity (+), including D-(+)-glucose / mannose / allose / galactose / xylose and L-(+)-arabinose / lythose / fructose / ribose, can achieve controlled synthesis of right-handed platinum-based alloy nanospires. Conversely, enantiomeric monosaccharides with negative optical activity (−), including L-(−)-glucose / mannose / allose / galactose / xylose and D-(−)-arabinose / lythose / fructose / ribose, can achieve controlled synthesis of left-handed platinum-based alloy nanospires, regardless of the D / L nomenclature (single chiral carbon atom) of the monosaccharide itself.
[0008] Technical solution: A chiral platinum-based alloy nanospiral catalyst, wherein the nanospiral has a chiral helical morphology and its helix direction is right-handed or left-handed, and the nanospiral comprises a platinum-based alloy, wherein the platinum-based alloy contains a noble metal component and a non-noble metal component, wherein the noble metal component is selected from at least one of platinum and iridium, and the non-noble metal component is selected from at least one of cobalt and nickel.
[0009] The atomic percentage of the above-mentioned precious metal components is 80% to 90%, and the atomic percentage of the non-precious metal components is 10% to 20%.
[0010] The aforementioned nanospirals have a face-centered cubic (fcc) crystal structure, with non-noble metal elements uniformly distributed at the atomic level throughout the material.
[0011] The aforementioned nanospirals have a length in the micrometer range, a diameter of 15 nm to 20 nm, and a pitch of 8 nm to 13 nm.
[0012] A method for preparing the above-mentioned chiral platinum-based alloy nanospiral catalyst includes the following steps: The raw materials are used in the following amounts: S1: Preparation of a metal salt precursor solution: The metal salt precursor, chiral monosaccharide, hexadecyltrimethylammonium bromide, and oleylamine solvent are mixed in the following proportions: the mass ratio of the metal salt precursor to hexadecyltrimethylammonium bromide is 1:(8~12); the mass ratio of the chiral monosaccharide to hexadecyltrimethylammonium bromide is 1:(2~5); the mass-volume ratio of hexadecyltrimethylammonium bromide to oleylamine is 50~60 mg:1 mL; ultrasonic stirring is performed to form a colloidal metal salt precursor solution; wherein, the amount of the metal salt precursor ensures that the atomic ratio of the noble metal component to the non-noble metal component is between 80:20 and 90:10, and adjusting the amount of chiral monosaccharide can control the helical pitch; S2: Preparation of platinum-based alloy nanospirals: The precursor solution from step S1 is heated to 150~170℃ and the reaction is maintained for 6~ After 10 hours of cooling, a mixed solution of hexane and ethanol in a volume ratio of 1:(4~6) was added, and the mixture was centrifuged and washed to obtain platinum-based alloy nanospirals; S3: Preparation of aqueous-phase dispersed platinum-based alloy nanospiral catalyst: Chiral monosaccharides were added to the dispersion of nanospirals in tetrahydrofuran obtained in step S2, in the following proportions: the mass ratio of nanospirals to chiral monosaccharides was 1:(8~10), and the mass-volume ratio of chiral monosaccharides to tetrahydrofuran was 5~6 mg:1 mL. After stirring, the mixture was centrifuged and washed, and then dispersed in deionized water.
[0013] The above-mentioned chiral monosaccharides are either positively optically active (+) or negatively optically active (−). Positively optically active monosaccharides induce the synthesis of dextrorotatory nanohelices, while negatively optically active monosaccharides induce the synthesis of levorotatory nanohelices.
[0014] The aforementioned positively optically active monosaccharides are selected from at least one of D-(+)-glucose, D-(+)-mannose, D-(+)-allose, D-(+)-galactose, D-(+)-xylose, L-(+)-arabinose, L-(+)-lythose, L-(+)-fructose, and L-(+)-ribose; the aforementioned negatively optically active monosaccharides are selected from at least one of L-(-)-glucose, L-(-)-mannose, L-(-)-allose, L-(-)-galactose, L-(-)-xylose, D-(-)-arabinose, D-(-)-lythose, D-(-)-fructose, and D-(-)-ribose.
[0015] In step S1, the amount of chiral monosaccharide added is used to control the pitch of the nanospiral, wherein the pitch is 13 nm when 120 mg of monosaccharide is added, the pitch is 11 nm when 180 mg of monosaccharide is added, and the pitch is 8 nm when 240 mg of monosaccharide is added.
[0016] The aforementioned metal salt precursors include at least one of platinum acetylacetonate, cobalt acetylacetonate, nickel acetylacetonate, and iridium acetylacetonate.
[0017] The above-mentioned chiral platinum-based alloy nanospiral catalyst is used in asymmetric catalytic reactions, including the oxidation of L / D-DOPA enantiomer molecules.
[0018] Beneficial effects: This invention dissolves a metal salt precursor and a surfactant (CTAB) in an oleylamine solvent, uses a certain type of chiral monosaccharide as a chiral inducer, and controls the chiral morphology characteristics such as the chiral direction and pitch of platinum-based alloy nanospirals by utilizing the chiral optical rotation and the amount of monosaccharide used, through a specific atomic ratio of noble metal / non-noble metal, as well as the control of reaction temperature, time, and heating rate. The reaction conditions are mild and the operation is simple. Attached Figure Description
[0019] Figure 1 Transmission electron microscope (TEM) images, scanning electron microscope (SEM) images, and high-resolution transmission electron microscope (HRTEM) images of the (ac) dextrorotatory / (df) levorotatory platinum-cobalt (PtCo) nanospirals regulated by D-(+)- / L-(−)-glucose prepared in this invention.
[0020] Figure 2 The elemental distribution of the (a) dextrorotatory / (b) levorotatory platinum-cobalt (PtCo) nanospirals regulated by D-(+)- / L-(−)-glucose prepared in this invention is shown in the scanning transmission electron microscopy (STEM) image.
[0021] Figure 3 The circular dichroism spectrum of the dextrorotatory / levorotatory platinum-cobalt (PtCo) nanospirals regulated by D-(+)- / L-(−)-glucose prepared in this invention demonstrates that they possess chiral optical signals.
[0022] Figure 4 is a comparison of the catalytic efficiency of the dextrorotatory / levorotatory platinum-cobalt (PtCo) nanospirals regulated by D-(+)- / L-(−)-glucose prepared in this invention as catalysts for the catalytic oxidation of D / L-DOPA with different configurations. Detailed Implementation
[0023] Example 1: D-(+)- / L-(−)-glucose-regulated dextrorotatory / levorotatory PtCo nanohelices
[0024] 1) Weigh 40 mg of platinum acetylacetonate, 7 mg of cobalt acetylacetonate, 120 mg of D-(+)- or L-(−)- glucose, 512 mg of cetyltrimethylammonium bromide and 10 mL of oleylamine solution, and sonicate and mix for 90 minutes to form a uniformly dispersed yellow gel-like solution.
[0025] 2) Subsequently, the uniformly dispersed yellow gelatinous solution was transferred to a 100 mL round-bottom glass flask. The temperature was raised from room temperature to 160 °C within 30 minutes using a heating mantle connected to a programmable temperature controller, and maintained at this temperature for 8 hours, forming a black gelatinous solution. After 8 hours, heating was stopped, and the reaction was allowed to cool to room temperature. A mixture of 5 mL hexane and 35 mL ethanol was added and poured into a 50 mL centrifuge tube. The tube was then centrifuged at 9000 rpm for 5 minutes, the supernatant was discarded, and the black solid at the bottom was retained. Then, 5 mL of hexane was added to redisperse the PtCo nanospirals, followed by 35 mL of ethanol for washing twice by centrifugation. The nanospirals were then dispersed in 10 mL of tetrahydrofuran solution for later use. D-(+)-glucose yields predominantly dextrorotatory PtCo nanospirals, while L-(−)-glucose yields predominantly levorotatory PtCo nanospirals. The atomic ratio of Pt / Co is approximately 80 / 20 to 90 / 10, forming a relatively obvious spiral morphology.
[0026] It should be noted that the pitch of the PtCo nanospirals obtained according to the above steps can be controlled within the range of 8 nm to 13 nm by adjusting the amount of glucose added in step 1). Specifically: 120 mg of D-(+)- or L-(−)- glucose can synthesize right-handed or left-handed PtCo nanospirals with a pitch of 13 nm; 180 mg of D-(+)- or L-(−)- glucose can synthesize right-handed or left-handed PtCo nanospirals with a pitch of 11 nm; and 240 mg of D-(+)- or L-(−)- glucose can synthesize right-handed or left-handed PtCo nanospirals with a pitch of 8 nm.
[0027] 3) Weigh 50 mg of the corresponding D-(+)- or L-(−)-glucose and add it to 10 mL of PtCo nanospiral / tetrahydrofuran dispersion. After ultrasonic dispersion, stir at room temperature for 24 hours. Then pour it into a 50 mL centrifuge tube, centrifuge at 9000 rpm for 5 minutes, pour off the supernatant, and redisperse the black product at the bottom in 5 mL of deionized water. Wash twice with deionized water by centrifugation, and finally disperse in a certain amount of deionized water to prepare an aqueously dispersed platinum-based alloy nanospiral catalyst, which can be used for subsequent catalytic oxidation of D / L-DOPA molecules.
[0028] Example 2: D-(+)- / L-(−)-glucose-regulated dextrorotatory / levorotatory PtNi nanohelices
[0029] 1) Weigh 40 mg of platinum acetylacetonate, 7 mg of nickel acetylacetonate, 120 mg of D-(+)- or L-(−)- glucose, 512 mg of cetyltrimethylammonium bromide and 10 mL of oleylamine solution, and sonicate and mix for 90 minutes to form a uniformly dispersed yellow-green gel solution.
[0030] 2) Subsequently, the uniformly dispersed yellow-green gelatinous solution was transferred to a 100 mL round-bottom glass flask. The temperature was raised from room temperature to 160 °C within 30 minutes using a heating mantle connected to a programmable temperature controller, and maintained at this temperature for 8 hours, forming a black gelatinous solution. After 8 hours, heating was stopped, and the reaction was allowed to cool to room temperature. A mixture of 5 mL hexane and 35 mL ethanol was added and poured into a 50 mL centrifuge tube. The tube was then centrifuged at 9000 rpm for 5 minutes, the supernatant was discarded, and the black solid at the bottom was retained. Then, 5 mL of hexane was added to redisperse the PtNi nanospirals, followed by 35 mL of ethanol for washing twice by centrifugation. The nanospirals were then dispersed in 10 mL of tetrahydrofuran solution for later use. D-(+)-glucose yields predominantly dextrorotatory PtNi nanospirals, while L-(−)-glucose yields predominantly levorotatory PtNi nanospirals. The atomic ratio of Pt / Ni is approximately 80 / 20 to 90 / 10, forming a relatively obvious spiral morphology.
[0031] 3) Weigh 50 mg of the corresponding D-(+)- or L-(−)-glucose and add it to 10 mL of PtNi nanospiral / tetrahydrofuran dispersion. After ultrasonic dispersion, stir at room temperature for 24 hours. Then pour it into a 50 mL centrifuge tube, centrifuge at 9000 rpm for 5 minutes, pour off the supernatant, and redisperse the black product at the bottom in 5 mL of deionized water. Wash twice with deionized water by centrifugation, and finally disperse in a certain amount of deionized water to prepare an aqueously dispersed platinum-based alloy nanospiral catalyst.
[0032] Example 3: D-(+)- / L-(−)-glucose-regulated dextrorotatory / levorotatory PtIrCo nanohelices
[0033] 1) Weigh 20 mg of platinum acetylacetone, 25 mg of iridium acetylacetone, 7 mg of cobalt acetylacetone, 120 mg of D-(+)- or L-(−)- glucose, 512 mg of cetyltrimethylammonium bromide and 10 mL of oleylamine solution, and sonicate and mix for 90 minutes to form a uniformly dispersed yellow gel-like solution.
[0034] 2) Subsequently, the uniformly dispersed yellow gelatinous solution was transferred to a 100 mL round-bottom glass flask. The temperature was raised from room temperature to 160 °C within 30 minutes using a heating mantle connected to a programmable temperature controller, and maintained at this temperature for 8 hours, forming a black gelatinous solution. After 8 hours, heating was stopped, and the reaction was allowed to cool to room temperature. A mixture of 5 mL hexane and 35 mL ethanol was added and poured into a 50 mL centrifuge tube. The tube was then centrifuged at 9000 rpm for 5 minutes, the supernatant was discarded, and the black solid at the bottom was retained. Then, 5 mL of hexane was added to redisperse the PtIrCo nanospirals, followed by 35 mL of ethanol for washing twice by centrifugation. The nanospirals were then dispersed in 10 mL of tetrahydrofuran solution for later use. D-(+)-glucose yields predominantly dextrorotatory PtIrCo nanospirals, while L-(−)-glucose yields predominantly levorotatory PtIrCo nanospirals. The atomic ratio of Pt / Ir / Co elements is approximately 40 / 40 / 20 to 45 / 45 / 10, forming a relatively obvious spiral morphology.
[0035] 3) Weigh 50 mg of the corresponding D-(+)- or L-(−)-glucose and add it to 10 mL of PtIrCo nanospiral / tetrahydrofuran dispersion. After ultrasonic dispersion, stir at room temperature for 24 hours. Then pour it into a 50 mL centrifuge tube, centrifuge at 9000 rpm for 5 minutes, pour off the supernatant, and redisperse the black product at the bottom in 5 mL of deionized water. Wash twice with deionized water by centrifugation, and finally disperse in a certain amount of deionized water to prepare an aqueously dispersed platinum-based alloy nanospiral catalyst.
[0036] Example 4: D-(+)- / L-(−)-glucose-regulated dextrorotatory / levorotatory PtCoNi nanohelices
[0037] 1) Weigh 40 mg of platinum acetylacetonate, 3.5 mg of cobalt acetylacetonate, 3.5 mg of nickel acetylacetonate, 120 mg of D-(+)- or L-(−)- glucose, 512 mg of cetyltrimethylammonium bromide and 10 mL of oleylamine solution, and sonicate and mix for 90 minutes to form a uniformly dispersed yellow-green gel solution.
[0038] 2) Subsequently, the uniformly dispersed yellow-green gelatinous solution was transferred to a 100 mL round-bottom glass flask. The temperature was raised from room temperature to 160 °C within 30 minutes using a heating mantle connected to a programmable temperature controller, and maintained at this temperature for 8 hours, forming a black gelatinous solution. After 8 hours, heating was stopped, and the reaction was allowed to cool to room temperature. A mixture of 5 mL hexane and 35 mL ethanol was added and poured into a 50 mL centrifuge tube. The tube was then centrifuged at 9000 rpm for 5 minutes, the supernatant was discarded, and the black solid at the bottom was retained. Then, 5 mL of hexane was added to redisperse the PtCoNi nanospirals, followed by 35 mL of ethanol for washing twice by centrifugation. The nanospirals were then dispersed in 10 mL of tetrahydrofuran solution for later use. D-(+)-glucose yields predominantly dextrorotatory PtCoNi nanospirals, while L-(−)-glucose yields predominantly levorotatory PtCoNi nanospirals. The atomic ratio of Pt / Co / Ni elements is approximately 80 / 10 / 10 to 90 / 5 / 5, forming a relatively obvious spiral morphology.
[0039] 3) Weigh 50 mg of the corresponding D-(+)- or L-(−)-glucose and add it to 10 mL of PtCoNi nanospiral / tetrahydrofuran dispersion. After ultrasonic dispersion, stir at room temperature for 24 hours. Then pour it into a 50 mL centrifuge tube, centrifuge at 9000 rpm for 5 minutes, pour off the supernatant, and redisperse the black product at the bottom in 5 mL of deionized water. Wash twice with deionized water by centrifugation, and finally disperse in a certain amount of deionized water to prepare an aqueously dispersed platinum-based alloy nanospiral catalyst.
[0040] Example 5: Dextrorotatory / levorotatory PtCo nanohelices regulated by other D-(+)- / L-(-)- monosaccharides (mannose / allose / galactose / xylose)
[0041] 1) Weigh 40 mg of platinum acetylacetonate, 7 mg of cobalt acetylacetonate, 120 mg of D-(+)- or L-(−)-mannose / allose / galactose (or 100 mg of D-(+)- or L-(−)-xylose), 512 mg of cetyltrimethylammonium bromide and 10 mL of oleylamine solution, and ultrasonically stir and mix for 90 minutes to form a uniformly dispersed yellow gel-like solution.
[0042] 2) Subsequently, the uniformly dispersed yellow gelatinous solution was transferred to a 100 mL round-bottom glass flask. The temperature was raised from room temperature to 160 °C within 30 minutes using a heating mantle connected to a programmable temperature controller, and maintained at this temperature for 8 hours, forming a black gelatinous solution. After 8 hours, heating was stopped, and the reaction was allowed to cool to room temperature. A mixture of 5 mL hexane and 35 mL ethanol was added and poured into a 50 mL centrifuge tube. The tube was then centrifuged at 9000 rpm for 5 minutes, the supernatant was discarded, and the black solid at the bottom was retained. Then, 5 mL of hexane was added to redisperse the PtCo nanospirals, followed by 35 mL of ethanol for washing twice by centrifugation. The nanospirals were then dispersed in 10 mL of tetrahydrofuran solution for later use. D-(+)- monosaccharides yield predominantly dextrorotatory PtCo nanospirals, while L-(−)- monosaccharides yield predominantly levorotatory PtCo nanospirals. The atomic ratio of Pt / Co is approximately 80 / 20 to 90 / 10, forming a relatively obvious spiral morphology.
[0043] 3) Weigh 50 mg of the corresponding D-(+)- or L-(−)- monosaccharide and add it to 10 mL of PtCo nanospiral / tetrahydrofuran dispersion. After ultrasonic dispersion, stir at room temperature for 24 hours. Then pour it into a 50 mL centrifuge tube, centrifuge at 9000 rpm for 5 minutes, pour off the supernatant, and redisperse the black product at the bottom in 5 mL of deionized water. Wash twice with deionized water by centrifugation, and finally disperse in a certain amount of deionized water to prepare an aqueously dispersed platinum-based alloy nanospiral catalyst.
[0044] Example 6: L- / D-rotary PtCo nanohelices regulated by other D-(−)- / L-(+)- monosaccharides (arabinose / lyseose / fructose / ribose)
[0045] 1) Weigh 40 mg of platinum acetylacetonate, 7 mg of cobalt acetylacetonate, 100 mg of D-(−)- or L-(+)-arabinose / lythose / ribose (or 50 mg of D-(-)- or L-(+)-fructose), 512 mg of cetyltrimethylammonium bromide and 10 mL of oleylamine solution, and ultrasonically stir and mix for 90 minutes to form a uniformly dispersed yellow gel-like solution.
[0046] 2) Subsequently, the uniformly dispersed yellow gelatinous solution was transferred to a 100 mL round-bottom glass flask. The temperature was raised from room temperature to 160 °C within 30 minutes using a heating mantle connected to a programmable temperature controller, and maintained at this temperature for 8 hours, forming a black gelatinous solution. After 8 hours, heating was stopped, and the reaction was allowed to cool to room temperature. A mixture of 5 mL hexane and 35 mL ethanol was added and poured into a 50 mL centrifuge tube. The tube was then centrifuged at 9000 rpm for 5 minutes, the supernatant was discarded, and the black solid at the bottom was retained. Then, 5 mL of hexane was added to redisperse the PtCo nanospirals, followed by 35 mL of ethanol for washing twice by centrifugation. The nanospirals were then dispersed in 10 mL of tetrahydrofuran solution for later use. D-(−)- monosaccharides yield predominantly levorotatory PtCo nanospirals, while L-(+)- monosaccharides yield predominantly dextrorotatory PtCo nanospirals. The atomic ratio of Pt / Co is approximately 80 / 20 to 90 / 10, forming a relatively obvious spiral morphology.
[0047] 3) Weigh 50 mg of the corresponding D-(−)- or L-(+)- monosaccharide and add it to 10 mL of PtCo nanospiral / tetrahydrofuran dispersion. After ultrasonic dispersion, stir at room temperature for 24 hours. Then pour it into a 50 mL centrifuge tube, centrifuge at 9000 rpm for 5 minutes, pour off the supernatant, and redisperse the black product at the bottom in 5 mL of deionized water. Wash twice with deionized water by centrifugation, and finally disperse in a certain amount of deionized water to prepare an aqueously dispersed platinum-based alloy nanospiral catalyst.
[0048] Example 7: Performance test of enzyme-like catalysis of DOPA enantiomeric oxidation by chiral PtCo nanospirals
[0049] Following the preparation method of chiral PtCo helical nanowires in Example 1, right-handed and left-handed PtCo nanohelices were prepared respectively. Then, the absorption peak intensity at 475 nm in the UV-Vis absorption spectrum was measured for the catalytic oxidation of different concentrations of chiral L / D-DOPA molecules (2.0 mM, 1.5 mM, 1.0 mM, 0.8 mM, 0.6 mM, 0.4 mM, 0.2 mM, 0.1 mM, 0.05 mM). (The absorption value at this point is the peak value of the absorption peak of dopachrome, the oxidation product of DOPA molecules). This yielded the Michaelis-Menten equation fitting curve for the reaction rate as a function of substrate concentration. From the Michaelis-Menten fitting curve, the relevant enzyme-catalyzed catalytic reaction kinetic parameters were obtained: k cat (Catalytic activity) and K m(Affinity constant), thus the catalytic efficiency of this PtCo nanospiral catalyst can be calculated: k eff = k cat / K m With catalytic selectivity factor: Select factor = k eff [L- / D-DOPA] / k eff [D- / L-DOPA] (Select factor ≥ 1). Using this method, the catalytic efficiency k of the right-handed PtCo nanospiral for the oxidation of L-DOPA can be measured. eff For 439 s -1 g -1 The catalytic efficiency k for the oxidation of D-DOPA eff For 134 s -1 g -1 The enantiocatalytic selectivity factor for DOPA is 3.28. The catalytic efficiency (k) of the left-handed PtCo nanospiral for the oxidation of L-DOPA is... eff 131s -1 g -1 The catalytic efficiency k for the oxidation of D-DOPA eff For 343 s -1 g -1 The enantiocatalytic selectivity factor for DOPA was 2.62. Compared with previously reported catalysts for the enantiocatalytic oxidation of DOPA, chiral PtCo helical nanowires showed superior catalytic efficiency and selectivity. See Tables 1-11 for a comparison of catalyst performance.
[0050] Table 1 Comparison of Catalyst Performance 1
[0051]
[0052] Table 2 Comparison of Catalyst Performance
[0053]
[0054] Table 3 Comparison of Catalyst Performance
[0055]
[0056] Table 4 Comparison of Catalyst Performance
[0057]
[0058] Table 5 Comparison of Catalyst Performance
[0059]
[0060] Table 6 Comparison of Catalyst Performance
[0061]
[0062] Table 7 Comparison of Catalyst Performance
[0063]
[0064] Table 8 Comparison of Catalyst Performance
[0065]
[0066] Table 9 Comparison of Catalyst Performance
[0067]
[0068] Table 10 Comparison of Catalyst Performance
[0069]
[0070] Table 11 Comparison of Catalyst Performance
[0071]
[0072] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and illustrations shown and described herein.
Claims
1. A chiral platinum-based alloy nanospiral catalyst, characterized in that, The nanospiral has a chiral helical morphology, with a right-handed or left-handed helical direction, and the nanospiral comprises a platinum-based alloy containing a noble metal component and a non-noble metal component, wherein the noble metal component is selected from at least one of platinum and iridium, and the non-noble metal component is selected from at least one of cobalt and nickel.
2. The chiral platinum-based alloy nanospiral catalyst according to claim 1, characterized in that, The atomic percentage of the precious metal component is 80% to 90%, and the atomic percentage of the non-precious metal component is 10% to 20%.
3. The chiral platinum-based alloy nanospiral catalyst according to claim 1, characterized in that, The nanospiral has a face-centered cubic (fcc) crystal structure, with non-noble metal elements uniformly distributed at the atomic level in the material.
4. The chiral platinum-based alloy nanospiral catalyst according to claim 1, characterized in that, The length of the nanospiral is on the micrometer scale, the diameter is 15 nm to 20 nm, and the pitch is 8 nm to 13 nm.
5. A method for preparing a chiral platinum-based alloy nanospiral catalyst as described in any one of claims 1-4, characterized in that, Includes the following steps: The raw materials are used in the following amounts: S1: Preparation of metal salt precursor solution: The metal salt precursor, chiral monosaccharide, hexadecyltrimethylammonium bromide, and oleylamine solvent are mixed in the following proportions: the mass ratio of metal salt precursor to hexadecyltrimethylammonium bromide is 1: (8-12); the mass ratio of chiral monosaccharide to hexadecyltrimethylammonium bromide is 1: (2-5); the mass-volume ratio of hexadecyltrimethylammonium bromide to oleylamine is 50-60 mg: 1 mL; ultrasonic stirring is performed to form a colloidal metal salt precursor solution; wherein, the amount of the metal salt precursor is such that the atomic ratio of the noble metal component to the non-noble metal component is between 80:20 and 90:10, and the helical pitch can be controlled by adjusting the amount of chiral monosaccharide; S2: Preparation of platinum-based alloy nanospiral wire: The precursor solution of step S1 is heated to 150-170℃ and the reaction is maintained for 6- After 10 hours of cooling, a mixed solution of hexane and ethanol in a volume ratio of 1:(4~6) was added, and the mixture was centrifuged and washed to obtain platinum-based alloy nanospirals; S3: Preparation of aqueous-phase dispersed platinum-based alloy nanospiral catalyst: Chiral monosaccharides were added to the dispersion of nanospirals in tetrahydrofuran obtained in step S2, in the following proportions: the mass ratio of nanospirals to chiral monosaccharides was 1:(8~10), and the mass-volume ratio of chiral monosaccharides to tetrahydrofuran was 5~6 mg:1 mL. After stirring, the mixture was centrifuged and washed, and then dispersed in deionized water.
6. The method according to claim 5, characterized in that, The chiral monosaccharide has positive optical rotation (+) or negative optical rotation (−), wherein positively optical ...
7. The method according to claim 6, characterized in that, The positively optically active monosaccharide is selected from at least one of D-(+)-glucose, D-(+)-mannose, D-(+)-allose, D-(+)-galactose, D-(+)-xylose, L-(+)-arabinose, L-(+)-lythose, L-(+)-fructose, and L-(+)-ribose; the negatively optically active monosaccharide is selected from at least one of L-(-)-glucose, L-(-)-mannose, L-(-)-allose, L-(-)-galactose, L-(-)-xylose, D-(-)-arabinose, D-(-)-lythose, D-(-)-fructose, and D-(-)-ribose.
8. The method according to claim 5, characterized in that, In step S1, the amount of chiral monosaccharide added is used to control the pitch of the nanospiral, wherein the pitch is 13 nm when 120 mg of monosaccharide is added, the pitch is 11 nm when 180 mg of monosaccharide is added, and the pitch is 8 nm when 240 mg of monosaccharide is added.
9. The method according to claim 5, characterized in that, The metal salt precursor includes at least one of platinum acetylacetonate, cobalt acetylacetonate, nickel acetylacetonate, and iridium acetylacetonate.
10. The application of the chiral platinum-based alloy nanospiral catalyst according to any one of claims 1-4 in asymmetric catalytic reactions, wherein the asymmetric catalytic reaction comprises the oxidation reaction of L / D-DOPA enantiomer molecules.