Molybdenum-based catalyst and preparation method and application thereof

Abstract

The invention provides a molybdenum-based catalyst and a preparation method and application thereof. The molybdenum-based catalyst comprises a molybdenum-based carrier and at least two metals loaded on the molybdenum-based carrier, and the molybdenum-based carrier is selected from at least one of alpha-MoC, beta-Mo2C, MoN, MoS2 and MoP; the metals are selected from at least two of ruthenium, rhodium, palladium, iridium, platinum and gold. The molybdenum-based catalyst provided by the invention is applied to hydrogen production by selective reforming of ethanol, and has relatively high hydrogen production efficiency and acetic acid selectivity.

Description

Technical Field

[0001] The present application relates to the field of catalyst technology, and in particular to a molybdenum-based catalyst and a preparation method and application thereof. Background Art

[0002] Hydrogen energy is a safe, clean, high-energy-density secondary energy source. Since it was proposed in the 20th century, the hydrogen energy system has received widespread attention and development and is regarded as the best choice for the future energy system. The reforming of fossil fuels, especially the reforming of methane or coal, is currently the main way to produce industrial hydrogen. Although these reforming processes are efficient and cost-effective, they are accompanied by large amounts of carbon dioxide emissions (about 830 million tons per year worldwide), which have adverse effects on the environment. In order to reduce the carbon footprint of hydrogen production, more environmentally friendly alternatives are being explored, such as water electrolysis and biomass gasification, but these methods face bottlenecks in efficiency, cost-effectiveness and scalability. The reforming hydrogen production process starting from ethanol has a huge advantage in carbon footprint.

[0003] Partial oxidation of ethanol (C2H5OH+1.5O2=2CO2+3H2) or full steam reforming (C2H5OH+3H2O=2CO2+6H2) have been actively studied as possible hydrogen production methods, especially using bio-derived renewable ethanol. Although these processes are superior to traditional hydrogen production routes in some aspects, partial oxidation is inherently limited by the low stoichiometric hydrogen productivity. At the same time, the highly endothermic nature of full steam reforming requires high operating temperatures, which can reach 350°C, which favors the occurrence of side reactions and reduces the efficiency of hydrogen production. In addition, both pathways convert 100% of carbon atoms into carbon dioxide, which not only consumes carbon resources, but also requires the integration of carbon capture and storage (CCS) technology to reduce the overall carbon footprint of hydrogen production. Summary of the invention

[0004] The purpose of this application is to provide a molybdenum-based catalyst to improve the hydrogen production efficiency of ethanol reforming hydrogen production, and at the same time to produce acetic acid with high selectivity to reduce the carbon footprint of hydrogen production; at the same time, a preparation method and application of the molybdenum-based catalyst are provided. The specific technical scheme is as follows:

[0005] The first aspect of the present application provides a platinum-based catalyst, which includes a platinum-based carrier and at least two metals loaded on the platinum-based carrier, wherein the platinum-based carrier is selected from at least one of α-MoC, β-Mo2C, MoN, MoS2, and MoP; and the metal is selected from at least two of ruthenium, rhodium, palladium, iridium, platinum, and gold. The platinum-based catalyst of the present application increases the dispersion of the loaded metals at the same loading by loading at least two metals on the platinum-based carrier, thereby increasing the density of active sites at the reforming interface and maximizing the hydrogen production efficiency of reforming hydrogen production. In addition, during the catalytic process, the catalyst can maintain the CC bond of ethanol, produce acetic acid with high selectivity, and reduce the carbon footprint of hydrogen production.

[0006] In some embodiments of the present application, the mass ratio of the platinum-based carrier to the metal is 100:20-100:1.

[0007] In some embodiments of the present application, the molybdenum-based carrier is selected from any one of α-MoC, β-Mo2C, MoN, MoS2, and MoP.

[0008] The second aspect of the present application provides a method for preparing the molybdenum-based catalyst provided in the first aspect of the present application, which comprises the following steps:

[0009] (1) After the deionized water is ultrasonically exhausted, the dissolved oxygen in the deionized water is removed by bubbling with inert gas;

[0010] (2) adding a platinum-based carrier to deionized water after exhaust and deoxygenation, stirring, and evacuating the atmosphere in the reaction container to obtain a suspension of the platinum-based carrier;

[0011] (3) using a metal salt solution impregnation method to load at least two metals on the platinum-based carrier to obtain a platinum-based catalyst;

[0012] (4) activating the molybdenum-based catalyst to obtain an activated molybdenum-based catalyst.

[0013] In some embodiments of the present application, the metal salt solution impregnation method includes: dissolving at least two metal salts in deionized water after exhaust gas deoxygenation, respectively, to obtain at least two metal salt solutions; and simultaneously loading at least two metals contained in the at least two metal salt solutions on the platinum-based carrier to obtain a platinum-based catalyst.

[0014] In other embodiments of the present application, the metal salt solution impregnation method includes: dissolving at least two metal salts in deionized water after exhaust gas deoxygenation, respectively, to obtain at least two metal salt solutions; loading at least two metals contained in the at least two metal salt solutions on the platinum-based carrier in sequence; and activating and passivating the platinum-based catalyst obtained by one loading, and then loading it for the next time, until the at least two metals are all loaded on the platinum-based carrier to obtain a platinum-based catalyst.

[0015] In some embodiments of the present application, the loading step includes: adding the one or at least two metal salt solutions to the platinum-based carrier suspension, evacuating the atmosphere in the reaction vessel, and continuing stirring for 0.5h to 4h to obtain a catalyst precursor solution, and removing the liquid from the catalyst precursor solution by rotary evaporation to obtain a platinum-based catalyst.

[0016] In some embodiments of the present application, the concentration of the platinum-based carrier suspension is 2 mg / mL-40 mg / mL, and the concentration of the metal salt solution is 0.1 mg / mL-20 mg / mL.

[0017] In some embodiments of the present application, the activation conditions are: activation at 400°C-700°C for 0.5h-4h in a 5-25% CH4 / H2 atmosphere; the passivation conditions are: the activated molybdenum-based catalyst is cooled to room temperature in a 5-25% CH4 / H2 atmosphere, and then passivated in a 0.2-1% O2 / Ar atmosphere for 6h-24h.

[0018] The third aspect of the present application provides an application of the molybdenum-based catalyst provided in the first aspect of the present application in the selective reforming of ethanol to produce hydrogen.

[0019] Beneficial effects of this application:

[0020] The present application provides a molybdenum-based catalyst, a preparation method and an application thereof. The molybdenum-based catalyst has a high density of active sites on the interface and can efficiently promote the partial steam reforming of ethanol to generate hydrogen and acetic acid (C2H5OH+H2O=CH3COOH+2H2) at a temperature much lower than that required for the traditional complete steam reforming of ethanol. It has dual advantages: 1) The reforming process extracts hydrogen from ethanol and water, and from a stoichiometric point of view, more hydrogen is produced than the dehydrogenation process; 2) The carbon atoms remain in the liquid phase, generating valuable chemical product acetic acid, showing extremely low carbon emissions, eliminating the need for CCS, in sharp contrast to other reforming pathways. Compared with traditional routes, this method has potential profitability and significantly reduces carbon emissions and fossil fuel consumption, showing the prospect of scalable green hydrogen production.

[0021] Of course, implementing any product or method of the present application does not necessarily require achieving all of the advantages described above at the same time. DETAILED DESCRIPTION

[0022] The following will be combined with the embodiments of the present application to clearly and completely describe the technical solutions in the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by those skilled in the art based on the present application belong to the scope of protection of the present application.

[0023] Hydrogen energy is a safe, clean, high-energy-density secondary energy source and is considered the best choice for the future energy system. Due to the environmental friendliness and renewability of ethanol, ethanol reforming to produce hydrogen has become a current research hotspot, but the partial oxidation of ethanol to produce hydrogen is essentially limited by the stoichiometrically low hydrogen productivity, and the highly endothermic nature of ethanol complete steam reforming to produce hydrogen requires a high operating temperature, which is conducive to the occurrence of side reactions. In addition, both pathways convert 100% of the carbon atoms into carbon dioxide. Based on this, the present application provides a molybdenum-based catalyst, a preparation method and an application thereof, which can efficiently promote the partial steam reforming of ethanol to produce hydrogen and acetic acid at a temperature far lower than that required for conventional complete steam reforming of ethanol.

[0024] The first aspect of the present application provides a platinum-based catalyst, which includes a platinum-based carrier and at least two metals loaded on the platinum-based carrier, wherein the platinum-based carrier is selected from at least one of α-MoC, β-Mo2C, MoN, MoS2, and MoP; and the metal is selected from at least two of ruthenium, rhodium, palladium, iridium, platinum, and gold.

[0025] The inventors discovered that the molybdenum-based carrier can effectively promote the dissociation of water. Moreover, unlike single-component metal-loaded molybdenum-based catalysts, there is a synergistic effect between at least two loaded metals, which can improve the dispersion of the loaded metals at the same loading amount, thereby increasing the density of active sites on the reforming interface and maximizing the reaction activity of the catalyst.

[0026] In general, the molybdenum-based catalyst provided in the present application can suppress the undesired breakage of CC bonds during the partial steam reforming of ethanol, and has more active sites for the reforming reaction, and can produce acetic acid with high selectivity while efficiently producing hydrogen at a temperature far lower than that required for the complete steam reforming of traditional ethanol. Compared with the traditional hydrogen production method, the use of the molybdenum-based catalyst to catalyze the reforming of ethanol to produce hydrogen not only improves the efficiency of hydrogen production, but also reduces carbon emissions, eliminates the demand for CCS, and reduces production costs.

[0027] In some embodiments of the present application, the mass ratio of the platinum-based carrier to the metal is 100:20-100:1. For example, the mass ratio of the platinum-based carrier to the metal is 100:20, 100:17, 100:13, 100:9, 100:6, 100:3, 100:1, or a range consisting of any two of these values. By regulating the mass ratio of the platinum-based carrier to the metal within the above range, it is beneficial to disperse the metal on the surface of the platinum-based carrier, while improving the catalyst reaction activity and maintaining good selectivity.

[0028] In some embodiments of the present application, the molybdenum-based carrier is selected from any one of α-MoC, β-Mo2C, MoN, MoS2, and MoP. The use of the above-mentioned types of molybdenum-based carriers can significantly improve the activity and stability of the catalyst, improve the hydrogen production efficiency in the process of selective reforming of ethanol to produce hydrogen, and compared with precious metal catalysts, it is beneficial to reduce the use cost of the catalyst.

[0029] The second aspect of the present application provides a method for preparing the molybdenum-based catalyst provided in the first aspect of the present application, which comprises the following steps:

[0030] (1) After the deionized water is ultrasonically exhausted, the dissolved oxygen in the deionized water is removed by bubbling with inert gas;

[0031] (2) adding a platinum-based carrier to deionized water after exhaust and deoxygenation, stirring, and evacuating the atmosphere in the reaction container to obtain a suspension of the platinum-based carrier;

[0032] (3) using a metal salt solution impregnation method to load at least two metals on a platinum-based carrier to obtain a platinum-based catalyst;

[0033] (4) Activating the molybdenum-based catalyst to obtain an activated molybdenum-based catalyst.

[0034] The present application prepares a molybdenum-based catalyst by an impregnation method, and the preparation process is simple and easy, and does not require complicated equipment and operations. During the impregnation process, the metal salt can be fully adsorbed onto the surface of the carrier to form a catalyst, reduce waste, and improve the utilization rate of active metals. The preparation method of the present application can obtain a highly dispersed supported multi-metallic molybdenum-based catalyst, which has high reactivity and selectivity, can efficiently promote partial steam reforming of ethanol, generate hydrogen and acetic acid, and reduce carbon emissions from the hydrogen production process.

[0035] The present application has no particular restrictions on the type of inert gas, as long as the purpose of the present application can be achieved. For example, the inert gas can be argon. The present application has no particular restrictions on the type of reaction vessel, as long as the purpose of the present application can be achieved. For example, an Ar-filled displacement container can be used as a reaction vessel. The present application has no particular restrictions on the equipment used to evacuate the atmosphere in the reaction vessel, as long as the purpose of the present application can be achieved. For example, a double row of pipes can be used.

[0036] In some embodiments of the present application, the metal salt solution impregnation method includes: dissolving at least two metal salts in deionized water after exhaust gas deoxygenation, respectively, to obtain at least two metal salt solutions; and simultaneously loading at least two metals contained in the at least two metal salt solutions on a platinum-based carrier to obtain a platinum-based catalyst.

[0037] In other embodiments of the present application, the metal salt solution impregnation method includes: dissolving at least two metal salts in deionized water after exhaust gas deoxygenation, respectively, to obtain at least two metal salt solutions; loading at least two metals contained in the at least two metal salt solutions on a platinum-based carrier in sequence; and activating and passivating the platinum-based catalyst obtained by one loading, and then loading it for the next time, until at least two metals are all loaded on the platinum-based carrier to obtain a platinum-based catalyst.

[0038] In the present application, at least two metals may be loaded on a platinum-based carrier simultaneously, or at least two metals may be loaded on a platinum-based carrier sequentially. In the sequential loading process, the type of metal loaded each time is not particularly limited, as long as the purpose of the present application can be achieved. For example, one metal may be loaded at a time, or two metals may be loaded at a time.

[0039] In some embodiments of the present application, the loading step includes: adding one or at least two metal salt solutions to a suspension of a platinum-based carrier, evacuating the atmosphere in the reaction vessel, and continuing stirring for 0.5 h to 4 h to obtain a catalyst precursor solution, and removing liquid from the catalyst precursor solution by rotary evaporation to obtain a platinum-based catalyst. Controlling the stirring time within the above range is conducive to sufficient contact and mixing between the metal salt solution and the platinum-based carrier, ensuring that the metal can be evenly and fully loaded on the platinum-based carrier, and increasing the metal loading.

[0040] In some embodiments of the present application, the concentration of the platinum-based carrier suspension is 2 mg / mL-40 mg / mL, and the concentration of the metal salt solution is 0.1 mg / mL-20 mg / mL. For example, the concentration of the platinum-based carrier suspension can be 2 mg / mL, 7.8 mg / mL, 15 mg / mL, 22 mg / mL, 30 mg / mL, 34 mg / mL, 40 mg / mL, or a range consisting of any two of the values; the concentration of the metal salt solution can be 0.1 mg / mL, 1.8 mg / mL, 4 mg / mL, 8 mg / mL, 12 mg / mL, 16 mg / mL, 20 mg / mL, or a range consisting of any two of the values. By regulating the concentration of the platinum-based carrier suspension and the concentration of the metal salt solution within the above range, the agglomeration of the platinum-based carrier in the aqueous solution can be avoided, the metal is fully loaded on the platinum-based carrier, and a uniform and stable platinum-based catalyst is obtained.

[0041] In some embodiments of the present application, the activation conditions are: in a 5-25% CH4 / H2 atmosphere, activation at 400°C-700°C for 0.5h-4h; the passivation conditions are: the activated molybdenum-based catalyst is cooled to room temperature in a 5-25% CH4 / H2 atmosphere, and then passivated in a 0.2-1% O2 / Ar atmosphere for 6h-24h. For example, the activation temperature is 400°C, 450°C, 500°C, 590°C, 670°C, 700°C, or a range consisting of any two of the values; the activation time is 0.5h, 2h, 3h, 4h, or a range consisting of any two of the values; the passivation time is 6h8h, 12h, 16h, 20h, 24h, or a range consisting of any two of the values. By regulating the activation conditions and passivation conditions within the above range, a molybdenum-based catalyst with high reactivity and selectivity can be obtained, which can effectively catalyze ethanol reforming to produce hydrogen, and produce acetic acid with high selectivity while efficiently producing hydrogen.

[0042] The third aspect of the present application provides an application of the molybdenum-based catalyst provided in the first aspect of the present application in the selective reforming of ethanol to produce hydrogen. The use of the catalyst provided in the present application in the selective reforming of ethanol to produce hydrogen can effectively promote the partial steam reforming of ethanol at a temperature far lower than that required for conventional ethanol steam reforming to produce hydrogen, improve the efficiency of hydrogen production, and selectively generate acetic acid, thereby reducing carbon emissions in the hydrogen production process.

[0043] Example

[0044] The following examples and comparative examples are given to more specifically describe the embodiments of the present application. Various tests and evaluations were performed according to the following methods. In addition, unless otherwise specified, "parts" and "%" are based on mass.

[0045] Example 1

[0046] <Preparation of molybdenum-based catalyst>

[0047] 10mL of deionized water was ultrasonically exhausted for 30 minutes, and then Ar gas was bubbled for 20 minutes to remove dissolved oxygen in the water; 300mg of α-MoC carrier was added, stirring was started, and the atmosphere in the container was replaced by Ar gas using a double-row pipe to obtain an α-MoC carrier suspension; 9mg of Pt and 9mg of Ir were dissolved in 5ml of deionized water after exhaust and deoxygenation, and iridium chloride was added dropwise to the α-MoC carrier suspension under stirring, and the atmosphere in the container was replaced by Ar gas using a double-row pipe; stirring for 1h, and the liquid was removed by rotary evaporation at 30°C to obtain a catalyst. The catalyst was activated at 590°C in a 15% CH4 / H2 atmosphere for 2h to obtain an activated catalyst A1.

[0048] <Test of catalytic performance of molybdenum-based catalyst>

[0049] 100 mg of A1 catalyst was placed in a straight quartz tube, quartz wool was filled above and below the catalyst bed, quartz sand was filled on the upper part of the bed, and reaction carrier gas (Ar / H2 / N2=5 / 5 / 90, 60 mL / min) was introduced. The tail end of the reactor was connected to a cold trap for collecting liquid products, and the rear end was connected in series with an online gas chromatograph for analyzing gas products. A heating program was set, and the temperature was raised to the target reaction temperature (270°C) under a carrier gas atmosphere and maintained for 0.5 h until the online chromatogram was the same as the reaction carrier gas component.

[0050] The reaction solution (the molar ratio of ethanol to water is 1:9) that has been ultrasonically degassed and has had its dissolved oxygen removed by Ar gas flow is connected to a micro-liquid injection pump. The liquid flow rate is set to 5 mL / h. The liquid enters the reaction tube after passing through the vaporization device at the front end of the reaction tube to react.

[0051] The experiment found that the PtIr bimetallic catalyst A1 achieved a hydrogen production rate of 331.3 mmolH2 / (gcat·h) and an acetic acid selectivity of 84.5% at 270°C.

[0052] Hydrogen production rate = amount of hydrogen substance / (catalyst mass × reaction time)

[0053] The amount of hydrogen was measured by gas chromatography equipped with a thermal conductivity detector (TCD).

[0054] Acetic acid selectivity = amount of acetic acid / amount of all carbon-containing product substances × 100%

[0055] The amount of acetic acid was determined by gas chromatography equipped with a flame ionization detector (FID).

[0056] Example 2

[0057] <Preparation of molybdenum-based catalyst>

[0058] 10mL of deionized water was ultrasonically exhausted for 30 minutes, and then Ar gas was bubbled for 20 minutes to remove dissolved oxygen in the water; 300mg of α-MoC carrier was added, stirring was started, and the atmosphere in the container was replaced by Ar gas using a double-row pipe to obtain an α-MoC carrier suspension; 3mg of Pt and 3mg of Au in chloroplatinic acid and chloroauric acid were dissolved in 5ml of deionized water after exhaust and deoxygenation, respectively, and added dropwise to the suspension of α-MoC carrier under stirring, and the atmosphere in the container was replaced by Ar gas using a double-row pipe; stirring for 1h, and the liquid was removed by rotary evaporation at 30°C to obtain a catalyst. The catalyst was activated at 590°C in a 15% CH4 / H2 atmosphere for 2h to obtain an activated catalyst A2.

[0059] <Test of catalytic performance of molybdenum-based catalyst>

[0060] Except for using molybdenum-based catalyst A2 instead of molybdenum-based catalyst A1, the rest is the same as the <Test of Catalytic Performance of Molybdenum-Based Catalyst> in Example 1.

[0061] The experiment found that the PtAu bimetallic catalyst A2 achieved a hydrogen production rate of 260.5 mmolH2 / (gcat·h) and an acetic acid selectivity of 75.2% at 270°C.

[0062] Example 3

[0063] <Preparation of molybdenum-based catalyst>

[0064] 10mL of deionized water was ultrasonically exhausted for 30 minutes, and then Ar gas was bubbled for 20 minutes to remove dissolved oxygen in the water; 300mg of Mo2S carrier was added, stirring was started, and the atmosphere in the container was replaced by Ar gas by evacuating with a double-row pipe to obtain a Mo2S carrier suspension; rhodium chloride and chloroplatinic acid containing 60mgRh and 60mgPt were dissolved in 5ml of deionized water after exhaust and deoxygenation, and added dropwise to the suspension of Mo2S carrier under stirring, and the atmosphere in the container was replaced by Ar gas by evacuating with a double-row pipe; stirring for 1h, and the liquid was removed by rotary evaporation at 30℃ to obtain a catalyst. The catalyst was activated at 590℃ for 2h in a 15% CH4 / H2 atmosphere to obtain an activated catalyst A3.

[0065] <Test of catalytic performance of molybdenum-based catalyst>

[0066] Except for using molybdenum-based catalyst A3 instead of molybdenum-based catalyst A1, the rest is the same as the <Test of Catalytic Performance of Molybdenum-Based Catalyst> in Example 1.

[0067] The experiment found that the RhPt bimetallic catalyst A3 achieved a hydrogen production rate of 280.2 mmolH2 / (gcat·h) and an acetic acid selectivity of 78.2% at 270°C.

[0068] Example 4

[0069] <Preparation of molybdenum-based catalyst>

[0070] 10mL of deionized water was ultrasonically exhausted for 30 minutes, and then Ar gas was bubbled for 20 minutes to remove dissolved oxygen in the water; 300mg of MoN carrier was added, stirring was started, and the atmosphere in the container was replaced by Ar gas using a double-row pipe to obtain a MoN carrier suspension; 9mg of Ru and 9mg of Pd were dissolved in 5ml of deionized water after exhaust and deoxygenation, and added dropwise to the MoN carrier suspension under stirring, and the atmosphere in the container was replaced by Ar gas using a double-row pipe; stirring for 1 hour, and the liquid was removed by rotary evaporation at 30°C to obtain a catalyst. The catalyst was activated at 590°C for 2 hours in a 15% CH4 / H2 atmosphere to obtain an activated catalyst A3.

[0071] <Test of catalytic performance of molybdenum-based catalyst>

[0072] Except for using molybdenum-based catalyst A4 instead of molybdenum-based catalyst A1, the rest is the same as the <Test of Catalytic Performance of Molybdenum-Based Catalyst> in Example 1.

[0073] The experiment found that the RuPd bimetallic catalyst A4 achieved a hydrogen production rate of 220.5 mmolH2 / (gcat·h) and an acetic acid selectivity of 68.7% at 270°C.

[0074] Example 5

[0075] <Preparation of molybdenum-based catalyst>

[0076] 10mL of deionized water was exhausted by ultrasonic treatment for 30 minutes, and then Ar gas was bubbled for 20 minutes to remove dissolved oxygen in the water; 300mg of α-MoC carrier was added, stirring was started, and the atmosphere in the container was replaced by Ar by evacuating the air with a double-row pipe to obtain an α-MoC carrier suspension; 9mg of Pt-containing chloroplatinic acid was dissolved in 5ml of deionized water after exhaust and deoxygenation, and the mixture was added dropwise to the suspension of the α-MoC carrier under stirring, and the atmosphere in the container was replaced by Ar by evacuating the air with a double-row pipe; stirring for 1h, and the liquid was removed by rotary evaporation at 30°C to obtain the first loaded catalyst; the first loaded catalyst was activated at 590°C in a 15% CH4 / H2 atmosphere for 2h, cooled to room temperature in a 15% CH4 / H2 atmosphere, and then passivated in a 0.5% O2 / Ar atmosphere for 12h to obtain the passivated catalyst. Dissolve 9 mg of Ir-containing chloroplatinic acid in 5 ml of deionized water after exhaust and deoxygenation, add dropwise to the passivated catalyst under stirring, evacuate the atmosphere in the container with Ar to replace the atmosphere; stir for 1 hour, and remove the liquid by rotary evaporation at 30°C to obtain a catalyst loaded with two metals. Activate the catalyst loaded with two metals at 590°C in a 15% CH4 / H2 atmosphere for 2 hours to obtain an activated catalyst A5.

[0077] <Test of catalytic performance of molybdenum-based catalyst>

[0078] Except for using molybdenum-based catalyst A5 instead of molybdenum-based catalyst A1, the rest is the same as the <Test of Catalytic Performance of Molybdenum-Based Catalyst> in Example 1.

[0079] The experiment found that the PtIr bimetallic catalyst A5 prepared by the sequential loading method achieved a hydrogen production rate of 274.2 mmolH2 / (gcat·h) and an acetic acid selectivity of 80.5% at 270°C.

[0080] Comparative Example 1

[0081] <Preparation of molybdenum-based catalyst>

[0082] The same procedure as in Example 1 was used except that the metal salt used was only chloroplatinic acid containing 18 mg of Pt, thereby obtaining a molybdenum-based catalyst B1.

[0083] <Test of catalytic performance of molybdenum-based catalyst>

[0084] Except for using the molybdenum-based catalyst B1 instead of the molybdenum-based catalyst A1, the rest is the same as the <Molybdenum-based catalyst catalytic performance test> of Example 1.

[0085] The experiment found that the single metal Pt catalyst B1 achieved a hydrogen production rate of 142.1 mmolH2 / (gcat·h) and an acetic acid selectivity of 52.1% at 270°C.

[0086] Comparative Example 2

[0087] <Preparation of molybdenum-based catalyst>

[0088] The same procedure as in Example 1 was followed except that the metal salt used was only iridium chloride containing 18 mg of Ir, to obtain a platinum-based catalyst B2.

[0089] <Test of catalytic performance of molybdenum-based catalyst>

[0090] Except for using the molybdenum-based catalyst B2 instead of the molybdenum-based catalyst A1, the rest is the same as the <Test of Catalytic Performance of Molybdenum-Based Catalyst> in Example 1.

[0091] The experiment found that the monometallic Ir catalyst B2 achieved a hydrogen production rate of 176.0 mmolH2 / (gcat·h) and an acetic acid selectivity of 58.4% at 270°C.

[0092] It can be seen from Examples 1 to 5 that the platinum-based catalyst prepared by using the platinum-based carrier and the loaded metal provided by the present application can efficiently promote the partial steam reforming of ethanol to generate hydrogen and acetic acid (C2H5OH+H2O=CH3COOH+2H2) at a temperature far lower than that required for the complete steam reforming of traditional ethanol. It can be seen from Examples 1 and 5 that at least two metal-loaded platinum-based catalysts can be prepared regardless of whether the method of simultaneous loading or sequential loading is adopted, and both have good catalytic activity and selectivity.

[0093] The PtIr bimetallic catalyst of Example 1 has a hydrogen production rate of 331.3 mmolH2 / (gcat·h) and an acetic acid selectivity of 84.5%, while the monometallic Pt catalyst of Comparative Example 1 has a hydrogen production rate of only 142.1 mmolH2 / (gcat·h) and an acetic acid selectivity of 52.1%, and the monometallic Ir catalyst of Comparative Example 2 has a hydrogen production rate of only 176.0 mmolH2 / (gcat·h) and an acetic acid selectivity of 58.4%. It can be seen from Example 1, Comparative Example 1 and Comparative Example 2 that the bimetallic catalyst exhibits a higher hydrogen production rate and acetic acid selectivity than the monometallic catalyst, indicating that there is a synergistic effect between the multiple supported metals, which can significantly improve the reaction activity and selectivity of the catalyst.

[0094] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

Claims

1. A platinum-based catalyst, comprising a platinum-based carrier and at least two metals supported on the platinum-based carrier, wherein the platinum-based carrier is selected from at least one of α-MoC, β-Mo2C, MoN, MoS2, and MoP; and the metal is selected from at least two of ruthenium, rhodium, palladium, iridium, platinum, and gold.

2. The platinum-based catalyst according to claim 1, wherein The mass ratio of the molybdenum-based carrier to the metal is 100:20-100:

1.

3. The platinum-based catalyst according to claim 1, wherein The molybdenum-based carrier is selected from any one of α-MoC, β-Mo2C, MoN, MoS2, and MoP.

4. A method for preparing a platinum-based catalyst as claimed in any one of claims 1 to 3, comprising the following steps: (1) After the deionized water is ultrasonically exhausted, the dissolved oxygen in the deionized water is removed by bubbling with inert gas; (2) adding a platinum-based carrier to deionized water after exhaust and deoxygenation, stirring, and evacuating the atmosphere in the reaction container to obtain a suspension of the platinum-based carrier; (3) using a metal salt solution impregnation method to load at least two metals on the platinum-based carrier to obtain a platinum-based catalyst; (4) activating the molybdenum-based catalyst to obtain an activated molybdenum-based catalyst.

5. The preparation method according to claim 4, wherein The metal salt solution impregnation method comprises: Dissolving at least two metal salts in deionized water after exhaust gas and deoxygenation to obtain at least two metal salt solutions; At least two metals contained in the at least two metal salt solutions are simultaneously loaded on the platinum-based carrier to obtain a platinum-based catalyst.

6. The preparation method according to claim 4, wherein The metal salt solution impregnation method comprises: Dissolving at least two metal salts in deionized water after exhaust gas and deoxygenation to obtain at least two metal salt solutions; sequentially loading at least two metals contained in the at least two metal salt solutions on the platinum-based carrier; After being activated and passivated, the platinum-based catalyst obtained by the first loading is subjected to the next loading until the at least two metals are fully loaded on the platinum-based carrier to obtain a platinum-based catalyst.

7. The preparation method according to claim 5 or 6, wherein: The loading steps include: The one or at least two metal salt solutions are added to the molybdenum-based carrier suspension, the atmosphere in the reaction container is evacuated, and stirring is continued for 0.5h to 4h to obtain a catalyst precursor solution. The catalyst precursor solution is subjected to rotary evaporation to remove liquid to obtain a molybdenum-based catalyst.

8. The preparation method according to any one of claims 4 to 6, wherein The concentration of the molybdenum-based carrier suspension is 2 mg / mL-40 mg / mL, and the concentration of metal ions in the metal salt solution is 0.1 mg / mL-20 mg / mL.

9. The preparation method according to any one of claims 4 to 6, wherein The activation conditions are: activation at 400°C-700°C for 0.5h-4h in a 5-25% CH4 / H2 atmosphere; the passivation conditions are: the activated molybdenum-based catalyst is cooled to room temperature in a 5-25% CH4 / H2 atmosphere, and then passivated in a 0.2-1% O2 / Ar atmosphere for 6h-24h.

10. Use of the molybdenum-based catalyst according to any one of claims 1 to 3 in the selective reforming of ethanol to produce hydrogen.