A method for preparing a quinary alloy nanoparticle

Abstract

The application discloses a kind of five-element alloy nanoparticles and preparation method and application thereof.The composition of the five-element alloy nanoparticles of the application includes carrier carbon black particles and supported Pt-Pd-Rh-Ru-Ni nanoparticles, and the preparation method includes the following steps: 1) dispersing Pt salt, Pd salt, Rh salt, Ru salt, Ni salt, carbon black and isopropyl alcohol in HCl solution to obtain a mixed dispersion;2) adding the mixed dispersion into polyol to carry out reduction reaction, and the five-element alloy nanoparticles are obtained.The five-element alloy nanoparticles of the application have the advantages of rich element types, small particle size, uniform composition, good catalytic performance, stable performance and the like, and the preparation process is simple, the reaction conditions are mild and environmentally friendly, and as an electrochemical catalyst, it can convert glycerol into a variety of high-value-added products through a one-step reaction, and has a broad application prospect.

Description

Technical Field

[0001] This invention relates to the field of electrochemical catalyst technology, specifically to a pentagonal alloy nanoparticle, its preparation method, and its application. Background Technology

[0002] Glycerin, a byproduct of biodiesel production and petrochemicals, is an important biomass feedstock and a typical polyol. With the surge in global fuel demand, the supply of glycerin is severely oversupplied, far exceeding market demand. Converting glycerin into value-added products is an efficient and environmentally friendly solution.

[0003] Currently, glycerol is mainly converted into high-value-added products through hydrogenolysis, polymerization, etherification, oxidation, dehydration, acetylation, and transesterification. Catalytic oxidation of glycerol is a promising method for producing various value-added products. Catalytic methods for glycerol include industrial thermocatalysis, bio-enzymatic catalysis, and electrocatalysis. Electrocatalysis is a method that combines energy and biomass conversion through redox reactions. It can be performed under mild conditions, without the need for high temperature, high pressure, or special equipment. Compared with traditional oxidation and reduction reactions, it produces less waste, does not generate toxic gases, and is sustainable, conforming to the main principles of green chemistry and carbon neutrality. Glycerol can be converted into corresponding ketones, aldehydes, and acids (e.g., dihydroxyacetone, glyceraldehyde, glyceric acid, hydroxypyruvic acid, tartaric acid, etc.) through thermal dehydration, catalytic dehydration, and electrocatalytic oxidation. These ketones, aldehydes, and acids are widely used in the cosmetics industry.

[0004] Therefore, developing a highly selective and highly active electrochemical catalyst is of great significance for the efficient utilization of glycerol. Summary of the Invention

[0005] The purpose of this invention is to provide a pentagonal alloy nanoparticle, its preparation method, and its application.

[0006] The technical solution adopted in this invention is:

[0007] A pentagonal alloy nanoparticle, comprising carrier carbon black particles and supported Pt-Pd-Rh-Ru-Ni nanoparticles.

[0008] Preferably, the mass ratio of the carbon black particles to the Pt-Pd-Rh-Ru-Ni nanoparticles is 2 to 20:1.

[0009] Preferably, the carbon black particles have a particle size of 40 nm to 100 nm.

[0010] Preferably, the particle size of the Pt-Pd-Rh-Ru-Ni nanoparticles is 3 nm to 10 nm.

[0011] A method for preparing pentagonal alloy nanoparticles as described above includes the following steps:

[0012] 1) Disperse Pt salt, Pd salt, Rh salt, Ru salt, Ni salt, carbon black and isopropanol in HCl solution to obtain a mixed dispersion;

[0013] 2) The mixed dispersion is added to a polyol for reduction reaction to obtain pentagonal alloy nanoparticles.

[0014] Preferably, the Pt salt in step 1) is at least one of potassium tetrachloroplatinate (K2PtCl4), sodium tetrachloroplatinate (Na2PtCl4), and chloroplatinic acid (H2PtCl6).

[0015] Preferably, the Pd salt in step 1) is at least one of potassium tetrachloropalladium (K2PdCl4), sodium tetrachloropalladium (Na2PdCl4), and potassium hexachloropalladium (K2PdCl6).

[0016] Preferably, the Rh salt in step 1) is at least one of rhodium trichloride (RhCl3), potassium hexachlororhodium (K3RhCl6), and sodium hexachlororhodium (Na3RhCl6).

[0017] Preferably, the Ru salt in step 1) is at least one of ruthenium trichloride (RuCl3), potassium hexachlororuthenate (K3RuCl6), and sodium hexachlororuthenate (Na3RuCl6).

[0018] Preferably, the Ni salt in step 1) is at least one of nickel chloride (NiCl2), nickel sulfate (NiSO4), and nickel carbonate (NiCO3).

[0019] Preferably, the mixed dispersion in step 2) is added by dropwise addition at a rate of 1 mL / min to 5 mL / min.

[0020] Preferably, the polyol in step 2) is at least one of ethylene glycol, glycerol, triethylene glycol, and pentaerythritol.

[0021] Preferably, the polyol in step 2) is preheated to 180°C to 230°C before use.

[0022] Preferably, the reduction reaction in step 2) is carried out at 180℃~230℃ for 10min~120min.

[0023] Preferably, after the reduction reaction in step 2) is completed, the reaction product is further purified and dried.

[0024] Preferably, the purification and drying process is as follows: the reaction solution obtained from the reduction reaction is cooled to room temperature, a mixture of acetone and diethyl ether is added and centrifuged, the precipitate obtained by centrifugation is washed multiple times with a mixture of diethyl ether, acetone, anhydrous ethanol and water, and then vacuum dried.

[0025] Preferably, the vacuum drying is carried out at 50℃ to 80℃ for 8h to 24h.

[0026] An electrochemical catalyst comprising the aforementioned pentagonal alloy nanoparticles.

[0027] A method for electrocatalytic oxidation of glycerol, using the aforementioned pentagonal alloy nanoparticles as the electrochemical catalyst.

[0028] The beneficial effects of this invention are: the five-element alloy nanoparticles of this invention have the advantages of rich element types, small particle size, uniform component dispersion, good catalytic performance, and stable performance. Moreover, its preparation process is simple, the reaction conditions are mild, and it is environmentally friendly. As an electrochemical catalyst, it can convert glycerol into a variety of high-value-added products in one step, and has broad application prospects.

[0029] Specifically:

[0030] 1) The five-element alloy nanoparticles of the present invention use carbon black as a carrier, which avoids the agglomeration of Pt-Pd-Rh-Ru-Ni nanoparticles and enables the Pt-Pd-Rh-Ru-Ni nanoparticles to be uniformly dispersed, thereby obtaining five-element alloy nanoparticles with smaller particle size. Compared with using PVP (polyvinylpyrrolidone) as a colloidal protectant, the product is easier to wash with organic solvents, reducing the amount of chemical reagents used, protecting the environment, avoiding oxidation reaction of five-element alloy nanoparticles during washing, and maintaining the electrocatalytic performance of the catalyst.

[0031] 2) The Pt-Pd-Rh-Ru-Ni nanoparticles in the pentaneous alloy nanoparticles of the present invention are prepared by co-reduction of noble metal salts and transition metal salts, forming a single-phase fcc solid solution structure, which not only maintains the good catalytic performance of noble metals, but also reduces production costs.

[0032] 3) The five-element alloy nanoparticles of the present invention have good electrochemical performance and high mass density of oxidation peak. Under a fixed potential, they can oxidize glycerol into various high-value-added products, thereby realizing the high-value-added conversion of glycerol, improving the utilization rate of glycerol, and effectively solving the problem of excess diesel by-products.

[0033] 4) The preparation process of the pentagonal alloy nanoparticles of the present invention is simple, does not require special instruments and equipment, the five metals can achieve co-reduction, the reaction conditions are mild, no toxic or harmful substances are produced, it is environmentally friendly, the product has stable performance, and has good application prospects. Attached Figure Description

[0034] Figure 1 The image shows the XRD pattern of the pentagonal alloy nanoparticles from Example 1.

[0035] Figure 2 The images shown are TEM and HRTEM images of the pentagonal alloy nanoparticles from Example 1.

[0036] Figure 3 This is a mapping diagram of the pentagonal alloy nanoparticles from Example 1.

[0037] Figure 4 The image shows the CV diagrams of the pentagonal alloy nanoparticles and the commercial Pt / C modified glassy carbon electrode from Example 1.

[0038] Figure 5 The image shows the pentagonal alloy nanoparticles of Example 1 and the commercial Pt / C modified glassy carbon electrode.

[0039] Figure 6 This is a product selectivity analysis diagram of the glassy carbon electrode modified with pentagonal alloy nanoparticles in Example 1. Detailed Implementation

[0040] The present invention will be further explained and described below with reference to specific embodiments.

[0041] Example 1:

[0042] A pentagonal alloy nanoparticle, the preparation method of which includes the following steps:

[0043] 1) Add 0.02 mmol of potassium tetrachloroplatinate (K2PtCl4), 0.02 mmol of potassium tetrachloropalladium (K2PdCl4), 0.02 mmol of rhodium trichloride hydrate (RhCl3·nH2O), 0.02 mmol of ruthenium trichloride hydrate (RuCl3·nH2O) and 0.02 mmol of nickel chloride hexahydrate (NiCl2·6H2O) to 15 mL of 0.1 mol / L HCl solution and mix thoroughly. Then add 5 mL of isopropanol and 0.2130 g of Cabot carbon black XC-72 and disperse by ultrasonication to obtain a mixed dispersion.

[0044] 2) The mixed dispersion was added dropwise to 150 mL of triethylene glycol (TEG) preheated to 230 °C at a rate of 1 mL / min. After the addition was complete, the mixture was kept at 230 °C for 15 min, then cooled to room temperature. 30 mL of a mixture of acetone and diethyl ether (volume ratio of acetone to diethyl ether was 1:1) was added, and the mixture was centrifuged at 11000 rpm for 5 min. The precipitate obtained by centrifugation was washed several times with a mixture of diethyl ether, acetone, anhydrous ethanol and water (volume ratio of diethyl ether, acetone, anhydrous ethanol and water was 1:1:1:0.5). The mixture was then vacuum dried overnight at 60 °C to obtain pentagonal alloy nanoparticles (black powder, denoted as PtPdRhRuNi / C).

[0045] Performance testing:

[0046] 1) The X-ray diffraction (XRD) pattern of the pentagonal alloy nanoparticles in this embodiment is shown below. Figure 1 As shown.

[0047] Depend on Figure 1 It can be seen that a single-phase fcc solid solution structure was indeed formed.

[0048] 2) The transmission electron microscope (TEM) and high-resolution transmission electron microscope (HRTEM) images of the pentagonal alloy nanoparticles in this embodiment are as follows: Figure 2 (a is a TEM image, b is an HRTEM image) as shown.

[0049] Depend on Figure 2 As can be seen from 'a', the Pt-Pd-Rh-Ru-Ni nanoparticles have a small particle size (about 5 nm) and are uniformly loaded on the surface of carbon black particles.

[0050] Depend on Figure 2 As can be seen from b, lattice fringes can be clearly seen, the lattice spacing is 2nm, corresponding to the (001) crystal plane of Pt crystal.

[0051] 3) The mapping diagram of the pentagonal alloy nanoparticles in this embodiment is as follows: Figure 3 As shown.

[0052] Depend on Figure 3 It can be seen that the spatial distribution of each element in the Pt-Pd-Rh-Ru-Ni nanoparticles is clearly visible. Both transition metals and noble metals are reduced and firmly fused together to form a single-phase fcc solid solution structure. This makes the synthesis of multi-element alloys no longer limited to noble metals. It not only provides more choices for the element combination of alloys, but also greatly reduces the synthesis cost. This shows that the five-element alloy nanoparticle preparation method of the present invention greatly reduces the synthesis difficulty compared with the existing multi-element alloy synthesis methods.

[0053] 4) Catalytic performance test:

[0054] a) Polish a glassy carbon electrode (circular) with a diameter of 3 mm to a mirror surface with Al2O3 powder with a diameter of 0.02 μm to 0.05 μm, rinse with distilled water, then ultrasonically clean in anhydrous ethanol and distilled water for 2 min each, then wash the electrode surface with distilled water and air dry at room temperature to obtain a pretreated glassy carbon electrode.

[0055] b) Mix 3 mg of the pentagonal alloy nanoparticles of this embodiment, 0.5 mL of water, 0.5 mL of isopropanol and 4 μL of Nafion solution with a mass fraction of 5% and then ultrasonically disperse for 2 h to prepare catalytic ink. Then take 5 μL of catalytic ink and drop it onto the pretreated glassy carbon electrode. Dry it under vacuum at room temperature overnight to obtain the working electrode (glassy carbon electrode modified with pentagonal alloy nanoparticles).

[0056] c) Prepare the working electrode using commercial Pt / C (20 wt%), following steps a) and b);

[0057] d) The working electrode, Hg / HgO electrode (reference electrode), and platinum sheet (counter electrode) were assembled into a three-electrode system, and an electrochemical test was conducted at room temperature in 10 mL of 1M KOH + 1M glycerol electrolyte (N2 was passed through for 30 min before the test to remove dissolved oxygen in the electrolyte; the working electrode needed to be activated before the electrochemical test to remove any impurities that might be present on the electrode surface, i.e., rapid scanning at a scan rate of 500 mV / s for several hundred cycles in 10 mL of 1M KOH electrolyte in the range of -1V to 1V; cyclic voltammetry was used during the test until the CV curve reached stability). The cyclic voltammetry (CV) plots of the pentagonal alloy nanoparticles of Example 1 and the commercial Pt / C modified glassy carbon electrode are shown in the figure. Figure 4 As shown, the chronoamperometry (it) of the pentagonal alloy nanoparticles of Example 1 and the commercial Pt / C-modified glassy carbon electrode in a 1M KOH + 1M glycerol electrolyte at a potential of -0.2V is illustrated in the figure. Figure 5 As shown, the product selectivity analysis of the glassy carbon electrode modified with pentagonal alloy nanoparticles in Example 1 in a 1M KOH + 1M glycerol electrolyte at a potential of -0.2V is shown in the figure. Figure 6 (The bar charts are arranged from top to bottom as GLA, FA, LA, GA, TA and OA).

[0058] Depend on Figure 4 It can be seen that the oxidation peak catalytic mass current density of the pentagonal alloy nanoparticles in this embodiment is 649.67 mA·mg. -1 Pt+Pd The oxidation peak catalytic mass current density of commercial Pt / C (20 wt%) is 46.567 mA·mg. -1 PtThe oxidation performance of the pentagonal alloy nanoparticles is about 14 times that of commercial Pt / C, indicating that the pentagonal alloy nanoparticles of the present invention have excellent electrochemical performance.

[0059] Depend on Figure 5 It can be seen that the glassy carbon electrode modified with pentagonal alloy nanoparticles in this embodiment has good stability.

[0060] Depend on Figure 6 It can be seen that six high-value-added products are generated: oxalic acid (OA), tartaric acid (TA), glycolic acid (GA), glyceric acid (GLA), lactic acid (LA), and formic acid (FA). Among them, FA is generated in the largest quantity, while OA is generated in the smallest quantity, indicating that there is a good selectivity.

[0061] Example 2:

[0062] A pentagonal alloy nanoparticle, the preparation method of which includes the following steps:

[0063] 1) Add 0.06 mmol of potassium tetrachloroplatinate (K2PtCl4), 0.01 mmol of potassium tetrachloropalladium (K2PdCl4), 0.01 mmol of rhodium trichloride hydrate (RhCl3·nH2O), 0.01 mmol of ruthenium trichloride hydrate (RuCl3·nH2O) and 0.01 mmol of nickel chloride hexahydrate (NiCl2·6H2O) to 15 mL of 0.1 mol / L HCl solution and mix thoroughly. Then add 5 mL of isopropanol and 0.2925 g of Cabot carbon black XC-72 and disperse by ultrasonication to obtain a mixed dispersion.

[0064] 2) The mixed dispersion was added dropwise to 150 mL of triethylene glycol preheated to 230 °C at a rate of 1 mL / min. After the addition was complete, the mixture was kept at 230 °C for 15 min, then cooled to room temperature. 30 mL of a mixture of acetone and diethyl ether (volume ratio of acetone and diethyl ether was 1:1) was added, and the mixture was centrifuged at 11000 rpm for 5 min. The precipitate obtained by centrifugation was washed several times with a mixture of diethyl ether, acetone, anhydrous ethanol and water (volume ratio of diethyl ether, acetone, anhydrous ethanol and water was 1:1:1:0.5). The mixture was then vacuum dried at 60 °C overnight to obtain pentagonal alloy nanoparticles (black powder, rich in Pt).

[0065] After testing (using the same testing method as in Example 1), the composition, structure and microstructure of the five-element alloy nanoparticles in this example are basically the same as those in Example 1, and the catalytic performance is good and stable, and the catalytic performance is close to that of the five-element alloy nanoparticles in Example 1.

[0066] Example 3:

[0067] A pentagonal alloy nanoparticle, the preparation method of which includes the following steps:

[0068] 1) Add 0.01 mmol of potassium tetrachloroplatinate (K2PtCl4), 0.06 mol of potassium tetrachloropalladium (K2PdCl4), 0.01 mmol of rhodium trichloride hydrate (RhCl3·nH2O), 0.01 mmol of ruthenium trichloride hydrate (RuCl3·nH2O) and 0.01 mmol of nickel chloride hexahydrate (NiCl2·6H2O) to 15 mL of 0.1 mol / L HCl solution and mix thoroughly. Then add 5 mL of isopropanol and 0.2083 g of Cabot carbon black XC-72 and disperse by ultrasonication to obtain a mixed dispersion.

[0069] 2) The mixed dispersion was added dropwise to 150 mL of triethylene glycol preheated to 230 °C at a rate of 1 mL / min. After the addition was complete, the mixture was kept at 230 °C for 15 min, then cooled to room temperature. 30 mL of a mixture of acetone and diethyl ether (volume ratio of acetone to diethyl ether was 1:1) was added, and the mixture was centrifuged at 11000 rpm for 5 min. The precipitate obtained by centrifugation was washed several times with a mixture of diethyl ether, acetone, anhydrous ethanol and water (volume ratio of diethyl ether, acetone, anhydrous ethanol and water was 1:1:1:0.5). The mixture was then vacuum dried at 60 °C overnight to obtain pentagonal alloy nanoparticles (black powder, rich in Pd).

[0070] After testing (using the same testing method as in Example 1), the composition, structure and microstructure of the five-element alloy nanoparticles in this example are basically the same as those in Example 1, and the catalytic performance is good and stable, and the catalytic performance is close to that of the five-element alloy nanoparticles in Example 1.

[0071] Example 4:

[0072] A pentagonal alloy nanoparticle, the preparation method of which includes the following steps:

[0073] 1) Add 0.01 mmol of potassium tetrachloroplatinate (K2PtCl4), 0.01 mmol of potassium tetrachloropalladium (K2PdCl4), 0.06 mmol of rhodium trichloride hydrate (RhCl3·nH2O), 0.01 mmol of ruthenium trichloride hydrate (RuCl3·nH2O) and 0.01 mmol of nickel chloride hexahydrate (NiCl2·6H2O) to 15 mL of 0.1 mol / L HCl solution and mix thoroughly. Then add 5 mL of isopropanol and 0.2050 g of Cabot carbon black XC-72 and disperse by ultrasonication to obtain a mixed dispersion.

[0074] 2) The mixed dispersion was added dropwise to 150 mL of triethylene glycol preheated to 230 °C at a rate of 1 mL / min. After the addition was complete, the mixture was kept at 230 °C for 15 min, then cooled to room temperature. 30 mL of a mixture of acetone and diethyl ether (volume ratio of acetone to diethyl ether was 1:1) was added, and the mixture was centrifuged at 11000 rpm for 5 min. The precipitate obtained by centrifugation was washed several times with a mixture of diethyl ether, acetone, anhydrous ethanol and water (volume ratio of diethyl ether, acetone, anhydrous ethanol and water was 1:1:1:0.5). The mixture was then vacuum dried at 60 °C overnight to obtain pentagonal alloy nanoparticles (black powder, rich in Rh).

[0075] After testing (using the same testing method as in Example 1), the composition, structure and microstructure of the five-element alloy nanoparticles in this example are basically the same as those in Example 1, and the catalytic performance is good and stable, and the catalytic performance is close to that of the five-element alloy nanoparticles in Example 1.

[0076] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A method for preparing pentagonal alloy nanoparticles, characterized in that, Includes the following steps: 1) Disperse Pt salt, Pd salt, Rh salt, Ru salt, Ni salt, carbon black and isopropanol in HCl solution to obtain a mixed dispersion; 2) The mixed dispersion is added to a polyol for reduction reaction to obtain pentagonal alloy nanoparticles; Step 2) The mixed dispersion is added dropwise at a rate of 1 mL / min to 5 mL / min. The pentagonal alloy nanoparticles consist of carrier carbon black particles and supported Pt-Pd-Rh-Ru-Ni nanoparticles; the mass ratio of the carbon black particles to the Pt-Pd-Rh-Ru-Ni nanoparticles is 2 to 20:1; the particle size of the carbon black particles is 40 nm to 100 nm; the particle size of the Pt-Pd-Rh-Ru-Ni nanoparticles is 3 nm to 10 nm; and the pentagonal alloy nanoparticles have a single-phase fcc solid solution structure.

2. The preparation method according to claim 1, characterized in that: Step 2) The polyol is at least one of ethylene glycol, glycerol, triethylene glycol, and pentaerythritol.

3. The preparation method according to claim 1, characterized in that: The reduction reaction in step 2) is carried out at 180℃~230℃ for 10min~120min.

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