Tin-based alloy catalyst as well as preparation method and application thereof

Abstract

The invention discloses a tin-based alloy catalyst and a preparation method and application thereof, and belongs to the technical field of catalysts. The catalyst comprises a carrier and an active component, the carrier comprises tin dioxide or metallic tin, and the active component is selected from at least one of transition metal and main group metal with catalytic action; the mass percent of the active component in the catalyst is 0.01%-30%, preferably 0.01%-10%. The active component is selected from metal with a catalytic action and an eutectic point of 500 DEG C or below. According to the tin-based alloy catalyst, high conductivity and an adjustable electronic structure promote efficient electron transmission, reaction kinetics is remarkably improved, and meanwhile the tin-based alloy catalyst shows excellent chemical stability in the catalysis process. The tin-based alloy catalyst provided by the invention is simple to prepare, low in cost, environment-friendly, high in conductivity and excellent in stability, and shows strong industrialization potential in the field of clean energy.

Description

Technical Field

[0001] This invention belongs to the field of catalyst technology, specifically relating to a tin-based alloy catalyst, its preparation method, and its application. Background Technology

[0002] Electrocatalysis technology, as a core means of achieving carbon neutrality, is crucial in CO2 reduction, water splitting for hydrogen production, and oxygen reduction fuel cells. Electrocatalytic CO2 reduction (CO2RR) requires the efficient conversion of inert CO2 into fuels (such as ethylene and formic acid), but faces challenges such as low selectivity, HER competition, and catalyst deactivation. Electrolytic water splitting for hydrogen production is limited by the high overpotentials of the cathode HER and anode OER, relies on precious metals (Pt, IrO2), and is costly. Fuel cell ORR, due to its slow kinetics, requires highly efficient catalysts (such as Pt-based or MNC single-atom materials) to reduce energy consumption.

[0003] Traditional carbon-based supports (such as graphene and carbon nanotubes) are widely used in electrocatalysis due to their high specific surface area, excellent conductivity, and low cost. However, they are prone to electrochemical corrosion in strongly acidic / alkaline environments and exhibit weak interactions with metal particles, leading to poor stability and agglomeration of active components. Alloy catalysts, with their tunable electronic structure, high conductivity, and excellent mechanical strength and chemical stability, demonstrate multiple advantages in energy conversion. Through the synergistic effect between metal components, their surface active site density and reaction kinetics are significantly improved, exhibiting superior performance compared to single-metal catalysts in key reactions of water electrolysis for hydrogen production, oxygen reduction in fuel cells, and metal-air batteries. Simultaneously, alloying strategies can effectively inhibit the migration and agglomeration of noble metal atoms, enhancing corrosion resistance and poisoning resistance. This provides an innovative path to solve problems such as the strong dependence on noble metals, rapid activity decay, and high-temperature sintering of traditional catalysts, opening up new directions for the design of high-performance catalytic systems.

[0004] Tin-based alloy catalysts exhibit unique catalytic performance advantages through the atomic-level synergistic effect of tin with other metals. Their multi-valence state characteristics effectively regulate the electronic structure of the alloy, optimizing the adsorption energy of active sites for reaction intermediates. Tin-based alloys also possess the advantages of high resource abundance, low cost, and environmental friendliness. Their combination with transition metals effectively alleviates dependence on precious metals, and the strong intermetallic interactions inhibit the oxidative dissolution of active components, providing opportunities for the development of efficient and durable green energy conversion devices. Summary of the Invention

[0005] The purpose of this invention is to solve the problems of poor catalytic activity, selectivity, and stability in electrocatalytic processes, reduce the overpotential required for the reaction, and provide a tin-based alloy catalyst, its preparation method, and its application. The tin-based alloy catalyst can provide carbon dioxide reduction performance with high selectivity and high stability. At the same time, the catalyst of this invention can be adapted to water electrolysis hydrogen production systems and fuel cell oxygen reduction reaction systems. While maintaining high power density output, it significantly reduces the reaction overpotential and exhibits excellent long-term operating durability.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A tin-based alloy catalyst, the catalyst comprising a support and an active component; the support comprising tin dioxide or metallic tin, the active component being selected from at least one of transition metals and main group metals having catalytic activity; the active component accounting for 0.01% to 30% of the catalyst by mass, preferably 0.01% to 10%.

[0008] Furthermore, the active component is selected from metals with a eutectic point below 500°C that have catalytic activity.

[0009] Further, the active component is at least one of magnesium, aluminum, calcium, scandium, vanadium, chromium, manganese, iron, nickel, cobalt, copper, zinc, gallium, germanium, zirconium, molybdenum, ruthenium, rhodium, palladium, silver, cadmium, indium, antimony, lanthanum, cerium, praseodymium, neodymium, hafnium, iridium, platinum, gold, lead, and bismuth, preferably at least one of manganese, cobalt, copper, zinc, palladium, silver, cadmium, indium, antimony, platinum, iridium, gold, lead, and bismuth.

[0010] A method for preparing the above-mentioned tin-based alloy catalyst, the method comprising the following steps:

[0011] S1: Tin metal is gradually heated and melted from room temperature in an anhydrous and oxygen-free atmosphere;

[0012] S2: Add the catalytic metal active component to molten tin, keep it at 200~500℃ for a period of time, disperse it evenly, and then cool it.

[0013] S3: The particle size of the tin metal-catalytic metal mixture obtained in step S2 is 1 nm to 1000 nm;

[0014] S4: Wash the mixture obtained in step S3 with ethanol and deionized water, and dry it to obtain a tin-based alloy catalyst.

[0015] Furthermore, in step S1, the termination heating temperature is 200~500℃, the single temperature gradient is ≤200℃, and the dwell time at each temperature point is 5~20min.

[0016] Further, in step S2, the heat preservation time is 1~7 h; the method of uniform dispersion is stirring or ultrasonic dispersion. Preferably, the ultrasonic dispersion frequency is 5~100kHz, and the stirring rate is 50~1000 rpm.

[0017] Further, in step S3, the method for reducing particle size includes ball milling or ultrafine pulverizing, wherein the ball milling time is 1~24h, the ball milling speed is 500~2000rpm, and the ball-to-material ratio is 25:1~4:1; the ultrafine pulverizing gas pressure is 0.2~1.5MPa, and the gas flow rate is 10~100m³ / h. 3 / h, crushing time 30min~12h, classifying wheel speed 500~3000r / min.

[0018] Furthermore, in step S3, the ambient atmosphere is one of argon, nitrogen, oxygen, helium, neon, xenon, and radon.

[0019] Further, in step S4, the drying is vacuum drying or ordinary drying, and the temperature is 50~100℃. Preferably, the drying method is vacuum drying.

[0020] The application of the tin-based alloy catalyst prepared by the above method as an electrocatalyst, wherein the catalyst is used as an electrocatalyst for hydrogen production by water electrolysis, as an oxygen reduction electrocatalyst for fuel cells, or as an electrocatalyst for carbon dioxide reduction.

[0021] The advantages of this invention over the prior art are as follows:

[0022] (1) The high conductivity and tunable electronic structure of tin-based alloy catalysts promote efficient electron transport, significantly improve reaction kinetics, and exhibit excellent chemical stability during catalysis.

[0023] (2) The tin-based alloy catalyst provided by the present invention is simple to prepare, low in cost and environmentally friendly, and has high conductivity and excellent stability, showing strong industrialization potential in the field of clean energy. Attached Figure Description

[0024] Figure 1 The distribution of electrocatalytic carbon dioxide reduction products and Faraday efficiency of the tin-copper alloy catalyst prepared in Example 1 of the present invention are shown.

[0025] Figure 2 The image shows the Faradaic efficiency of the tin oxide-supported palladium catalyst Pd / SnO2 prepared in Example 2 of the present invention for the electrocatalytic reduction of carbon dioxide to formic acid.

[0026] Figure 3The diagram shows the oxygen evolution polarization curve of the tin oxide-supported cobalt-iridium alloy catalyst IrCo / SnO2 prepared in Example 3 of the present invention under acidic conditions.

[0027] Figure 4 The linear sweep voltammetry (LSV) curves of the tin oxide-supported platinum single-atom catalyst Pt / SnO2 prepared in Example 4 of the present invention and the commercial platinum-carbon electrode in oxygen reduction are shown.

[0028] Figure 5 The linear sweep voltammetry (LSV) curves of the tin oxide-supported platinum single-atom catalyst Pt / SnO2 prepared in Example 4 of the present invention are shown after different cycles. Detailed Implementation

[0029] The embodiments of the present invention will be described below with reference to the accompanying drawings and preferred embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be understood that the preferred embodiments are only for illustrating the present invention and not for limiting the scope of protection of the present invention.

[0030] The present invention involves atomically dispersed melting of a tin-metal mixture in an anhydrous and oxygen-free environment, followed by ball milling of the tin-metal mixture under an inert or oxygen atmosphere, cleaning impurities with deionized water or ethanol, and drying to finally obtain tin metal-supported catalysts and tin dioxide-supported metal catalysts.

[0031] Example 1:

[0032] A method for preparing a tin-copper alloy catalyst CuSn, the method comprising:

[0033] S1: Metal Superdispersion: The metal dispersion experiment is conducted in an anhydrous and oxygen-free glove box to prevent the metal from reacting with moisture and oxygen in the air. A corresponding mass of metallic tin is placed in a nickel container and heated using a gradient heating method of room temperature - 50℃ - 100℃ - 150℃ - 200℃ - 250℃, with each temperature point held for 5~20 minutes to promote the complete conversion of tin into an erodible, highly liquid metal substrate. Preferably, the mass of metallic tin is 10g, the final gradient temperature is 250℃, and the single temperature gradient is ≤50℃.

[0034] S2: Weigh 0.5g of foamed copper metal and cut it into 4×4 cm pieces. 2Copper foam sheets are immersed in tin in batches. The ultra-high specific surface area of ​​the copper foam sheets increases the contact area with the liquid tin. Simultaneously, a magnetic stirrer is used to ensure that the catalytic metal is completely and uniformly dispersed in the tin at a stirring speed of 500 rpm. The tin-copper alloy is then poured onto a stainless steel plate and cooled to room temperature. Preferably, the copper foam has a porosity ≥95%, and the double-layer heating method is used to maintain the temperature for ≥0.5 hours.

[0035] S3: Ball milling: Mix the copper-tin mixture obtained in S2 with zirconium oxide grinding balls at a mass ratio of 10:1 and ball mill. Introduce argon gas at a flow rate of 150 mL / min, set the ball milling time to 2 hours, the rotation speed to 500 rpm, and ball mill for 15 minutes, followed by a 5-minute rest period to prevent side reactions caused by excessive temperature.

[0036] S4: The tin-copper alloy catalyst was washed with deionized water and ethanol and then dried to obtain the CuSn alloy catalyst, in which the copper content was 4.76 wt%.

[0037] Example 2:

[0038] A method for preparing a tin oxide-supported palladium catalyst Pd / SnO2 is disclosed. The difference between this embodiment and Example 1 is that the temperature in step S1 is room temperature - 50℃ - 100℃ - 150℃ - 200℃ - 280℃, and the mass of metallic tin is changed to 20g; in step S2, 0.5g of metallic copper is replaced with 0.22g of metallic palladium, the magnetic stirrer is replaced with an ultrasonic disperser with a power of 20kW and a dispersion time of 5h; and in step S3, ball milling is replaced with an ultrafine pulverizer with an ultrafine pulverizing gas pressure of 0.8MPa and a gas flow rate of 50m³ / h. 3 / h, argon gas was replaced with oxygen, the pulverization time was 5h, the classifying wheel speed was 1000r / min, the palladium loading was 0.8 wt%, and other conditions were the same as in Example 1.

[0039] Example 3:

[0040] A method for preparing a tin oxide-supported cobalt-iridium alloy catalyst IrCo / SnO2 is disclosed. The difference between this embodiment and Example 1 is that the temperature in step S1 is room temperature - 50℃ - 100℃ - 150℃ - 200℃ - 260℃, and the mass of metallic tin is replaced with 30g; the 0.5g copper metal in step S2 is replaced with 0.2g cobalt metal and 0.24g iridium metal wire; the argon gas in step S3 is replaced with oxygen, the flow rate is 200 mL / min, the ball milling time is 5h, and the rotation speed is 800rpm; wherein the loading of cobalt metal is 0.5wt% and the loading of iridium metal is 0.6wt%, and other conditions are consistent with those in Example 1.

[0041] Example 4:

[0042] A method for preparing a tin oxide-supported platinum single-atom catalyst Pt / SnO2 is disclosed. The difference between this embodiment and Example 1 is that the temperature in step S1 is room temperature - 50℃ - 100℃ - 150℃ - 200℃ - 270℃, the 0.5g copper metal in step S2 is replaced with 0.1g platinum metal, the argon gas in step S3 is replaced with oxygen gas at a flow rate of 200 mL / min, and the platinum metal loading is 0.7wt%.

[0043] Test Example 1: The tin-copper alloy catalyst CuSn prepared in Example 1 was selected, and its carbon dioxide reduction performance was tested in a carbon dioxide-saturated sodium bicarbonate solution (pH 6.8) using an H-type electrolytic cell and an electrochemical workstation. First, linear sweep voltammetry (LSV) was used with an initial scan rate of 5 mV / s and a potential range from 0 V to -1.3 V (relative to the reversible hydrogen electrode). Subsequently, chronoamperometry was used for 4000 seconds within a potential range of -0.4 V to -0.9 V to ensure catalyst stability and sufficient hydrocarbon formation. After the test, the product was collected to verify the catalyst's performance.

[0044] Test Example 2: The tin oxide-supported palladium catalyst Pd / SnO2 prepared in Example 2 was selected, and other conditions were kept the same as in Test Example 1.

[0045] Test Example 3: The tin oxide-supported cobalt-iridium alloy catalyst IrCo / SnO2 prepared in Example 3 was used. A catalyst slurry was prepared by adding 5 mg of catalyst, 60 μL of 5‰ perfluorinated sulfonate (nafion), and 2 mL of isopropanol. The glassy carbon electrode used had an area of ​​0.07 cm². 2 Electrochemical tests for OER were performed using an electrochemical workstation. Linear sweep voltammetry (LSV) was conducted in a 0.5 M H2SO4 electrolyte solution. The scan range was 1.0–1.8 V, and the scan rate was 5 mV / s. Mercurous sulfate, platinum wire, and glassy carbon electrodes were used as the reference electrode, counter electrode, and working electrode, respectively.

[0046] Test Example 4: The tin oxide-supported platinum single-atom catalyst Pt / SnO2 prepared in Example 4 was selected. The oxygen reduction reaction (ORR) performance of the catalyst was tested using an electrochemical workstation. The rotating disk electrode supporting the catalyst was used as the working electrode, the platinum ring electrode as the counter electrode, and the Hg / HgO electrode as the reference electrode. Before the electrochemical test, high-purity oxygen was passed into the electrolyte for 30 minutes to achieve oxygen saturation. The electrolyte was a 0.1 mol / L KOH solution. Linear sweep voltammetry was performed at a scan rate of 5 mV / s within the voltage range of 0.2 to -0.8 V, with a negative scan direction.

[0047] Comparative Example 1: An iridium catalyst supported on commercial carbon black was used, with other conditions remaining the same as in Test Example 3.

[0048] Comparative Example 2: A platinum-carbon catalyst supported on commercial carbon black was used, with other conditions remaining the same as in Test Example 4.

[0049] Figure 1 The images show the product distribution and Faraday efficiency of the tin-copper alloy catalyst prepared in Example 1 for the electrocatalytic reduction of carbon dioxide. The copper-tin catalyst achieved a selectivity of 90.8% for the electrocatalytic reduction of carbon dioxide to ethanol.

[0050] Figure 2 This image shows the Faradaic efficiency of the tin oxide-supported palladium catalyst Pd / SnO2 prepared in Example 2 for the electrocatalytic reduction of carbon dioxide to formic acid. Formic acid is an important organic acid with wide applications and significant value in industrial and economic fields. The catalyst prepared in this invention achieves a selectivity of over 90% for the reduction of carbon dioxide to formic acid over a wide voltage range of -0.4V to 0.8V.

[0051] Figure 3 The image shows the oxygen evolution polarization curve of the tin oxide-supported cobalt-iridium alloy catalyst IrCo / SnO2 prepared in Example 3 under acidic conditions. The catalyst prepared in this invention exhibits oxygen evolution polarization under 10 mA / cm² conditions. 2 The overpotential at this point is 285 mV, while the overpotential of the commercial catalyst in Comparative Example 1 is 10 mA / cm. 2 The overpotential was 315mV, indicating that the catalyst prepared in this invention has excellent water electrolysis performance.

[0052] Figure 4 Linear sweep voltammetry (LSV) curves of the tin oxide-supported platinum single-atom catalyst Pt / SnO2 prepared in Example 4 and a commercial platinum-carbon electrode during oxygen reduction. The catalyst prepared in this invention exhibits a high half-wave potential of 0.905 V.

[0053] Figure 5 The linear sweep voltammetry (LSV) curves of the tin oxide-supported platinum single-atom catalyst Pt / SnO2 prepared in Example 4 after different cycles showed only slight decay, indicating good structural stability.

[0054] The above embodiments are merely preferred embodiments provided to fully illustrate the present invention, and the scope of protection of the present invention is not limited thereto. Equivalent substitutions or modifications made by those skilled in the art based on the present invention are all within the scope of protection of the present invention.

Claims

1. A tin-based alloy catalyst, characterized in that: The catalyst comprises a support and an active component; the support comprises tin dioxide or metallic tin, and the active component is selected from at least one of transition metals and main group metals with catalytic activity; the active component accounts for 0.01% to 30% of the catalyst by mass.

2. The tin-based alloy catalyst according to claim 1, characterized in that: The active component is selected from metals with eutectic points below 500°C that have catalytic activity.

3. The tin-based alloy catalyst according to claim 2, characterized in that: The active component is at least one of the following: magnesium, aluminum, calcium, scandium, vanadium, chromium, manganese, iron, nickel, cobalt, copper, zinc, gallium, germanium, zirconium, molybdenum, ruthenium, rhodium, palladium, silver, cadmium, indium, antimony, lanthanum, cerium, praseodymium, neodymium, hafnium, iridium, platinum, gold, lead, and bismuth.

4. A method for preparing a tin-based alloy catalyst according to claim 1 or 2, characterized in that: The method includes the following steps: S1: Tin metal is gradually heated and melted from room temperature in an anhydrous and oxygen-free atmosphere; S2: Add the catalytic metal active component to molten tin, keep it at 200~500℃ for a period of time, disperse it evenly, and then cool it. S3: The particle size of the tin metal-catalytic metal mixture obtained in step S2 is 1 nm to 1000 nm; S4: Wash the mixture obtained in step S3 with ethanol and deionized water, and dry it to obtain a tin-based alloy catalyst.

5. The method for preparing a tin-based alloy catalyst according to claim 4, characterized in that: In step S1, the termination heating temperature is 200~500℃, the single temperature gradient is ≤200℃, and each temperature point is held for 5~20 minutes.

6. The method for preparing a tin-based alloy catalyst according to claim 4, characterized in that: In step S2, the heat preservation time is 1 to 7 hours; the method of uniform dispersion is stirring or ultrasonic dispersion.

7. The method for preparing a tin-based alloy catalyst according to claim 4, characterized in that: In step S3, the method for reducing particle size includes ball milling or ultrafine pulverizing, wherein the ball milling time is 1~24h, the ball milling speed is 500~2000rpm, and the ball-to-material ratio is 25:1~4:1; the ultrafine pulverizing gas pressure is 0.2~1.5MPa, and the gas flow rate is 10~100m³ / h. 3 / h, crushing time 30min~12h, classifying wheel speed 500~3000r / min.

8. The method for preparing a tin-based alloy catalyst according to claim 4, characterized in that: In step S3, the ambient atmosphere is one of argon, nitrogen, oxygen, helium, neon, xenon, and radon.

9. The method for preparing a tin-based alloy catalyst according to claim 4, characterized in that: In step S4, the drying is vacuum drying or ordinary drying, and the temperature is 50~100℃.

10. The application of the catalyst according to any one of claims 1 to 3 or the tin-based alloy catalyst prepared by the method according to any one of claims 4 to 10 as an electrocatalyst, characterized in that: The catalyst is used in at least one of the following applications: as an electrocatalyst for hydrogen production by water electrolysis, as an oxygen reduction electrocatalyst for fuel cells, and as an electrocatalyst for carbon dioxide reduction.

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