Supported catalyst for hydrogen production through methane cracking as well as preparation method and application of supported catalyst
The M/UZM-35 catalyst was prepared by introducing metal salt precursors into UZM-35 molecular sieve, and the problems of catalyst deactivation and insufficient activity were solved, thereby achieving efficient methane conversion and stable carbon material generation.
Patent Information
- Application Number
- CN202510509995.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-22
- Publication Date
- 2025-08-05
AI Technical Summary
The existing methane catalytic cracking hydrogen production catalysts have problems with inactivation in the carbon deposit problem, and the catalytic activity and stability are insufficient, making it difficult to effectively form high value-added carbon materials.
The metal salt precursor was introduced into the porous UZM-35 molecular sieve by immersion method to prepare an M/UZM-35 supported catalyst. The acid site of the catalyst is adjusted by adjusting the transition metal loading rate to form metal-support interactions and promote the formation of carbon nanotubes and carbon fibers.
The efficient catalytic performance of methane conversion rate ≥85.9% was achieved, and the catalyst had high activity and low energy consumption, and had strong resistance to carbon deposits.
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Figure CN120421031A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the field of hydrogen production, and in particular to an M / UZM-35 supported catalyst for methane cracking to produce hydrogen, a preparation method and applications thereof. Background Art
[0002] Hydrogen, due to its cleanliness, high specific energy density, and diverse sources, is considered one of the most important industrial raw materials and is widely used in organic synthesis, metallurgy, fuel cells, and other fields. Hydrogen production from fossil fuels is currently the most common method of hydrogen production. While coal-based hydrogen production is associated with the production of significant amounts of greenhouse gases, hydrogen production from natural gas is attracting even greater attention.
[0003] Natural gas is primarily composed of methane, which has a high hydrogen-to-carbon ratio by mass and is considered an ideal feedstock for hydrogen production. Currently, the main methods for producing hydrogen from methane include steam reforming, carbon dioxide reforming, partial oxidation reforming, autothermal reforming, and catalytic decomposition of methane. Catalytic cracking of methane can produce high-purity hydrogen while simultaneously generating amorphous carbon, carbon fibers, or carbon nanotubes, without producing carbon dioxide as a byproduct. Therefore, the development of this technology has attracted considerable attention in the industry. The key to hydrogen production from catalytic cracking of methane lies in the catalyst. Commonly used active metals for the catalyst are Ni, Fe, and Co, and supports include MgO, Al2O3, SiO2, and zeolites. Notably, during the catalytic cracking reaction, when the carbon production rate exceeds the diffusion rate of carbon within the active sites of the metal catalyst, the generated carbon will coat the catalyst surface, leading to catalyst deactivation. Therefore, there is an urgent need to develop a high-activity, low-energy-consumption, highly stable, and anti-coking catalyst for catalytic cracking of methane for hydrogen production. Summary of the Invention
[0004] The first technical problem addressed by the present invention is to provide a supported M / UZM-35 catalyst. This supported catalyst possesses metal-support interactions and acid sites, facilitating the formation of high-value-added carbon materials such as carbon nanotubes and carbon fibers. The supported M / UZM-35 catalyst exhibits highly efficient catalytic performance, achieving a methane conversion rate of ≥85.9%.
[0005] The second technical problem addressed by the present invention is to provide a method for preparing an M / UZM-35 supported catalyst. This method uses an impregnation method to introduce a metal salt precursor into the porous UZM-35 molecular sieve for modification. This simple preparation method allows the catalyst's acid sites, and thus its catalytic activity, to be adjusted by adjusting the transition metal loading.
[0006] The third technical problem to be solved by the present invention is to provide an application of an M / UZM-35 supported catalyst in the catalytic cracking of methane to produce hydrogen.
[0007] In order to solve the above-mentioned first technical problem, the technical solution adopted by the present invention is as follows:
[0008] An M / UZM-35 supported catalyst is composed of a UZM-35 carrier and metal Ni and Fe nanoparticles supported on the UZM-35 carrier;
[0009] The loading amount of the metal M nanoparticles is 5.0-30.0 wt.%;
[0010] The UZM-35 carrier is a plate-like structure.
[0011] In order to solve the above second technical problem, the technical solution adopted by the present invention is as follows:
[0012] A method for preparing an M / UZM-35 supported catalyst comprises the following steps:
[0013] 1) First, an aluminum source, a silicon source and a template are mixed, and then an aqueous solution of KOH or NaOH is added and stirred at room temperature to obtain a reaction solution; the reaction solution is transferred to an autoclave and heated at 150-180°C for 4-10 days; the solid product is recovered by centrifugation, washed with distilled water, and dried; then calcined in air at 400-600°C for 4-10 hours to remove the organic template; the calcined sample is ion exchanged in an aqueous solution of NH4NO3 at 50-100°C for 1-3 times, each time for 3-7 hours, to obtain NH4 + The sample is in the form of H-type; and then calcined at 400-600 ° C for 4-6 hours to obtain the UZM-35 molecular sieve in the form of H-type;
[0014] 2) dissolving the metal precursor containing M in an appropriate amount of ethanol solvent, adding the H-form UZM-35 molecular sieve obtained in step 1), and stirring to uniformly disperse it;
[0015] 3) removing ethanol using a rotary evaporator and drying in an oven to obtain a sample;
[0016] 4) Grinding the sample obtained in step 3) into powder, weighing the powder into a quartz tube, and reducing it in a mixed atmosphere of hydrogen and argon to obtain the M / UZM-35 supported catalyst.
[0017] Preferably, in step 1), the aluminum source is one or more of aluminum hydroxide, sodium aluminate, aluminum nitrate, aluminum chloride and aluminum isopropoxide; the silicon source is one or more of silicon dioxide, silica sol and tetraethyl orthosilicate; and the template is one or more of methyldipropylammonium hydroxide, tetrapropylammonium hydroxide and tetraethylammonium hydroxide.
[0018] Preferably, in step 1), the stirring time at room temperature is 1-4 hours.
[0019] Preferably, in step 1), the concentration of the aqueous solution of NH4NO3 is 0.8-1.2M.
[0020] Preferably, in step 1), the final composition of the reaction solution is (4-6)DMDPAOH·xK2O·(1-x)Na2O·yAl2O3·(5-20)SiO2·(100-200)H2O, wherein 0≤x≤1 and 0≤y≤1.
[0021] Preferably, in step 2), the stirring time is 1-2 hours; preferably, the metal precursor containing M is selected from one of nickel nitrate, nickel chloride, ferric nitrate and ferric chloride.
[0022] Preferably, in step 3), the operating temperature of the rotary evaporator is 40-70°C; and the drying temperature of the oven is 70-90°C.
[0023] Preferably, in step 4), the heating rate during the reduction treatment is 10-30°C / min, the reduction treatment temperature is 500-800°C, and the reduction treatment time is 3-4 hours; the hydrogen content in the hydrogen and argon mixed atmosphere is 2-20 vol%.
[0024] In order to solve the third technical problem mentioned above, the technical solution adopted by the present invention is as follows:
[0025] The invention discloses an application of an M / UZM-35 supported catalyst in the catalytic cracking of methane to produce hydrogen.
[0026] Preferably, the reaction temperature of the methane catalytic cracking reaction to produce hydrogen is 500-800°C.
[0027] Any range described in the present invention includes the end value and any numerical value between the end values and any sub-range formed by the end value or any numerical value between the end values.
[0028] Unless otherwise specified, all raw materials in the present invention can be purchased commercially, and the equipment used in the present invention can adopt conventional equipment in the relevant field or refer to the existing technology in the relevant field.
[0029] Compared with the prior art, the present invention has the following beneficial effects:
[0030] 1. The M / UZM-35 catalyst prepared by the present invention has metal-support interaction and acid sites, which are conducive to the formation of high-value-added carbon materials such as carbon nanotubes and carbon fibers.
[0031] 2. The present invention adopts an impregnation method to introduce a metal salt precursor into the porous UZM-35 molecular sieve for modification. The preparation method is simple and can adjust the acid site of the catalyst by adjusting the transition metal loading rate, thereby adjusting the catalytic activity of the catalyst.
[0032] 3. The present invention has proved that the M / UZM-35 catalyst has high catalytic performance through methane catalytic cracking hydrogen production reaction test, and the methane conversion rate is ≥85.9%. BRIEF DESCRIPTION OF THE DRAWINGS
[0033] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.
[0034] Figure 1 This is a scanning electron microscope image of the UZM-35 carrier prepared in Example 1 of the present invention;
[0035] Figure 2 This is a comparison chart of the performance evaluation of methane catalytic cracking reactions of Ni / UZM-35, 1-Ni / UZM-35, 2-Ni / UZM-35, 3-Ni / UZM-35, 4-Ni / UZM-35, 5-Ni / UZM-35 and 6-Ni / UZM-35 catalysts obtained in Example 1, Comparative Example 7, Comparative Example 8, Comparative Example 9, Comparative Example 10, Comparative Example 11 and Comparative Example 12 of the present invention.
[0036] Figure 3 This is a comparative diagram of the performance evaluation of the Ni / UZM-35 catalyst obtained in Example 1 of the present invention in the catalytic cracking reaction of methane at different temperatures. DETAILED DESCRIPTION
[0037] In order to more clearly illustrate the present invention, the present invention is further described below in conjunction with preferred embodiments and accompanying drawings. Similar components in the accompanying drawings are represented by the same reference numerals. It should be understood by those skilled in the art that the following detailed description is illustrative rather than restrictive and should not be used to limit the scope of protection of the present invention.
[0038] For ease of description, if the descriptions in the present invention involve "first", "second", etc., they are only set for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of such features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the fact that they can be implemented by ordinary technicians in this field. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.
[0039] As one aspect of the present invention, the present invention provides an M / UZM-35 supported catalyst, which is composed of a UZM-35 carrier and metal Ni and / or Fe nanoparticles supported on the UZM-35 carrier;
[0040] The loading amount of the metal M nanoparticles is 5.0-30.0 wt.%;
[0041] The UZM-35 carrier is a plate-like structure.
[0042] As another aspect of the present invention, a method for preparing a M / UZM-35 supported catalyst comprises the following steps:
[0043] 1) First, an aluminum source, a silicon source and a template are mixed, and then an aqueous solution of KOH or NaOH is added and stirred at room temperature to obtain a reaction solution; the reaction solution is transferred to an autoclave and heated at 150-180°C for 4-10 days; the solid product is recovered by centrifugation, washed with distilled water, and dried; then calcined in air at 400-600°C for 4-10 hours to remove the organic template; the calcined sample is ion exchanged in an aqueous solution of NH4NO3 at 50-100°C for 1-3 times, each time for 3-7 hours, to obtain NH4 + The sample is in the form of H-type; and then calcined at 400-600 ° C for 4-6 hours to obtain the UZM-35 molecular sieve in the form of H-type;
[0044] 2) dissolving the metal precursor containing M in an appropriate amount of ethanol solvent, adding the H-form UZM-35 molecular sieve obtained in step 1), and stirring to uniformly disperse it;
[0045] 3) removing ethanol using a rotary evaporator and drying in an oven to obtain a sample;
[0046] 4) Grinding the sample obtained in step 3) into powder, weighing the powder into a quartz tube, and reducing it in a mixed atmosphere of hydrogen and argon to obtain the M / UZM-35 supported catalyst.
[0047] In certain embodiments of the present invention, in step 1), the aluminum source is one or more of aluminum hydroxide, sodium aluminate, aluminum nitrate, aluminum chloride, and aluminum isopropoxide; the silicon source is one or more of silicon dioxide, silica sol, and tetraethyl orthosilicate; and the template is one or more of methyldipropylammonium hydroxide, tetrapropylammonium hydroxide, and tetraethylammonium hydroxide.
[0048] In certain embodiments of the present invention, in step 1), the stirring time at room temperature is 1-4 hours.
[0049] In certain embodiments of the present invention, in step 1), the concentration of the aqueous solution of NH4NO3 is 0.8-1.2M.
[0050] In certain embodiments of the present invention, in step 1), the final composition of the reaction solution is (4-6)DMDPAOH·xK2O·(1-x)Na2O·yAl2O3·(5-20)SiO2·(100-200)H2O, wherein 0≤x≤1 and 0≤y≤1.
[0051] In certain embodiments of the present invention, in step 2), the stirring time is 1-2 hours; and the metal precursor containing M is selected from one of nickel nitrate, nickel chloride, ferric nitrate, and ferric chloride.
[0052] In certain embodiments of the present invention, in step 3), the operating temperature of the rotary evaporator is 40-70°C; and the drying temperature of the oven is 70-90°C.
[0053] In certain embodiments of the present invention, in step 4), the heating rate during the reduction treatment is 10-30°C / min, the reduction treatment temperature is 500-800°C, and the reduction treatment time is 3-4 hours; and the hydrogen content in the hydrogen and argon mixed atmosphere is 2-20 vol%.
[0054] As another aspect of the present invention, the present invention provides an application of an M / UZM-35 supported catalyst in a methane catalytic cracking hydrogen production reaction.
[0055] In certain embodiments of the present invention, the reaction temperature of the methane catalytic cracking reaction to produce hydrogen is 500-800°C.
[0056] Example 1
[0057] A method for preparing a Ni / UZM-35 supported catalyst comprises the following steps:
[0058] 1) First, aluminum hydroxide, silicon dioxide and an aqueous solution of methyldipropylammonium hydroxide (DMDPAOH) are mixed; then, an aqueous solution of KOH or NaOH is added to the mixture; the final composition of the mixture is (4-6)DMDPAOH·xK2O·(1-x)Na2O·yAl2O3·(5-20)SiO2·(100-200)H2O, where x and y vary between 0≤x≤1 and 0≤y≤1, respectively; after stirring at room temperature for 2 hours, the synthesized mixture is placed in an autoclave and heated at 180°C for 7 days; the solid product is recovered by centrifugation and repeatedly washed with distilled water; after drying overnight, it is calcined in air at 550°C for 8 hours to remove organic SDA; the calcined sample is ion-exchanged twice in a 1.0M NH4NO3 aqueous solution at 80°C for 4 hours to obtain NH4 + The sample in the H form was then converted to the H form of UZM-35 by calcining at 550 °C for 4 hours;
[0059] 2) Impregnation method: 99 mg of Ni(NO3)2·6H2O was dissolved in 20 ml of ethanol solvent, 200 mg of the prepared UZM-35 molecular sieve material was added, and the mixture was stirred for 1 hour to uniformly disperse. The ethanol was removed using a rotary evaporator at 50°C, and the mixture was dried in an oven at 80°C.
[0060] 3) The sample obtained in step 2) was ground into a powder, and a certain amount of the powder was weighed into a quartz tube and subjected to a reduction treatment in a mixed atmosphere of hydrogen and argon. The temperature was raised to 600°C at a heating rate of 10°C / min, maintained for 2 hours, and then cooled to room temperature to obtain a Ni / UZM-35 supported catalyst.
[0061] Figure 1 The following is a scanning electron micrograph of the UZM-35 carrier prepared in this example. The scanning electron micrograph shows that the UZM-35 carrier has a plate-like structure.
[0062] Comparative Example 1
[0063] A method for preparing a 1-Ni / UZM-35 supported catalyst comprises the following steps:
[0064] 1) First, pseudo-boehmite, silica and an aqueous solution of methyldipropylammonium hydroxide (DMDPAOH) were mixed; then, an aqueous solution of KOH or NaOH was added to the mixture; after stirring at room temperature for 2 hours, the resulting mixture was placed in an autoclave and heated at 180°C for 7 days; the solid product was recovered by centrifugation and repeatedly washed with distilled water; after drying overnight, it was calcined in air at 550°C for 8 hours to remove the organic template; the calcined sample was ion exchanged twice with a 1.0M NH4NO3 aqueous solution at 80°C for 4 hours to obtain NH4 + The sample in the H form was then converted to the H form of UZM-35 by calcining at 550 °C for 4 hours;
[0065] 2) Impregnation method: 99 mg of Ni(NO3)2·6H2O was dissolved in 20 ml of ethanol solvent, 200 mg of the prepared UZM-35 molecular sieve material was added, and the mixture was stirred for 1 hour to uniformly disperse. The ethanol was removed using a rotary evaporator at 50°C, and the mixture was dried in an oven at 80°C.
[0066] 3) The sample obtained in step 2) was ground into a powder, and a certain amount of the powder was weighed into a quartz tube and subjected to a reduction treatment in a mixed atmosphere of hydrogen and argon. The temperature was increased to 600°C at a heating rate of 10°C / min, maintained for 2 hours, and then cooled to room temperature to obtain a 1-Ni / UZM-35 supported catalyst.
[0067] Comparative Example 2
[0068] A method for preparing a 2-Ni / UZM-35 supported catalyst comprises the following steps:
[0069] 1) First, aluminum hydroxide, silica sol and an aqueous solution of methyldipropylammonium hydroxide (DMDPAOH) were mixed; then, an aqueous solution of KOH or NaOH was added to the mixture; after stirring at room temperature for 2 hours, the resulting mixture was placed in an autoclave and heated at 180°C for 7 days; the solid product was recovered by centrifugation and repeatedly washed with distilled water; after drying overnight, it was calcined in air at 550°C for 8 hours to remove the organic template; the calcined sample was ion exchanged twice with a 1.0M NH4NO3 aqueous solution at 80°C for 4 hours to obtain NH4 + The sample in the H form was then converted to the H form of UZM-35 by calcining at 550 °C for 4 hours;
[0070] 2) Impregnation method: 99 mg of Ni(NO3)2·6H2O was dissolved in 20 ml of ethanol solvent, 200 mg of the prepared UZM-35 molecular sieve material was added, and the mixture was stirred for 1 hour to uniformly disperse. The ethanol was removed using a rotary evaporator at 50°C, and the mixture was dried in an oven at 80°C.
[0071] 3) The sample obtained in step 2) was ground into a powder, and a certain amount of the powder was weighed into a quartz tube and reduced in a mixed atmosphere of hydrogen and argon. The temperature was raised to 600°C at a heating rate of 10°C / min, maintained for 2 hours, and then cooled to room temperature to obtain a 2-Ni / UZM-35 supported catalyst.
[0072] Comparative Example 3
[0073] A method for preparing a 3-Ni / UZM-35 supported catalyst comprises the following steps:
[0074] 1) First, aluminum hydroxide, silicon dioxide and an aqueous solution of hexadecyltrimethylammonium bromide were mixed; then, an aqueous solution of KOH or NaOH was added to the mixture; after stirring at room temperature for 2 hours, the resulting mixture was placed in an autoclave and heated at 180°C for 7 days; the solid product was recovered by centrifugation and repeatedly washed with distilled water; after drying overnight, it was calcined in air at 550°C for 8 hours to remove the organic template; the calcined sample was ion exchanged twice with a 1.0M NH4NO3 aqueous solution at 80°C for 4 hours to obtain NH4 + The sample in the H form was then converted to the H form of UZM-35 by calcining at 550 °C for 4 hours;
[0075] 2) Impregnation method: 99 mg of Ni(NO3)2·6H2O was dissolved in 20 ml of ethanol solvent, 200 mg of the prepared UZM-35 molecular sieve material was added, and the mixture was stirred for 1 hour to uniformly disperse. The ethanol was removed using a rotary evaporator at 50°C, and the mixture was dried in an oven at 80°C.
[0076] 3) The sample obtained in step 2) was ground into a powder, and a certain amount of the powder was weighed into a quartz tube and subjected to a reduction treatment in a mixed atmosphere of hydrogen and argon. The temperature was raised to 600°C at a heating rate of 10°C / min, maintained for 2 hours, and then cooled to room temperature to obtain a 3-Ni / UZM-35 supported catalyst.
[0077] Comparative Example 4
[0078] A method for preparing a 4-Ni / UZM-35 supported catalyst comprises the following steps:
[0079] 1) First, aluminum hydroxide, silicon dioxide and an aqueous solution of methyldipropylammonium hydroxide (DMDPAOH) were mixed; then, an aqueous solution of KOH or NaOH was added to the mixture; after stirring at room temperature for 0.5 hours, the resulting mixture was placed in an autoclave and heated at 180°C for 7 days; the solid product was recovered by centrifugation and repeatedly washed with distilled water; after drying overnight, it was calcined in air at 550°C for 8 hours to remove the organic template; the calcined sample was ion exchanged twice with a 1.0M NH4NO3 aqueous solution at 80°C for 4 hours to obtain NH4 + The sample in the H form was then converted to the H form of UZM-35 by calcining at 550 °C for 4 hours;
[0080] 2) Impregnation method: 99 mg of Ni(NO3)2·6H2O was dissolved in 20 ml of ethanol solvent, 200 mg of the prepared UZM-35 molecular sieve material was added, and the mixture was stirred for 1 hour to uniformly disperse. The ethanol was removed using a rotary evaporator at 50°C, and the mixture was dried in an oven at 80°C.
[0081] 3) The sample obtained in step 2) was ground into a powder, and a certain amount of the powder was weighed into a quartz tube and subjected to a reduction treatment in a mixed atmosphere of hydrogen and argon. The temperature was raised to 600°C at a heating rate of 10°C / min, maintained for 2 hours, and then cooled to room temperature to obtain a 4-Ni / UZM-35 supported catalyst.
[0082] Comparative Example 5
[0083] A method for preparing a 5-Ni / UZM-35 supported catalyst comprises the following steps:
[0084] 1) First, aluminum hydroxide, silicon dioxide and an aqueous solution of methyldipropylammonium hydroxide (DMDPAOH) were mixed; then, an aqueous solution of KOH or NaOH was added to the mixture; after stirring at room temperature for 2 hours, the resulting mixture was placed in an autoclave and heated at 180°C for 7 days; the solid product was recovered by centrifugation and repeatedly washed with distilled water; after drying overnight, it was calcined in air at 550°C for 8 hours to remove the organic template; the calcined sample was ion exchanged twice in a 0.3M NH4NO3 aqueous solution at 80°C for 4 hours to obtain NH4 + The sample in the H form was then converted to the H form of UZM-35 by calcining at 550 °C for 4 hours;
[0085] 2) Impregnation method: 99 mg of Ni(NO3)2·6H2O was dissolved in 20 ml of ethanol solvent, 200 mg of the prepared UZM-35 molecular sieve material was added, and the mixture was stirred for 1 hour to uniformly disperse. The ethanol was removed using a rotary evaporator at 50°C, and the mixture was dried in an oven at 80°C.
[0086] 3) The sample obtained in step 2) was ground into a powder, and a certain amount of the powder was weighed into a quartz tube and reduced in a mixed atmosphere of hydrogen and argon. The temperature was raised to 600°C at a heating rate of 10°C / min, maintained for 2 hours, and then cooled to room temperature to obtain a 5-Ni / UZM-35 supported catalyst.
[0087] Comparative Example 6
[0088] A method for preparing a 6-Ni / UZM-35 supported catalyst comprises the following steps:
[0089] 1) First, aluminum hydroxide, silicon dioxide and an aqueous solution of methyldipropylammonium hydroxide (DMDPAOH) were mixed; then, an aqueous solution of KOH or NaOH was added to the mixture; after stirring at room temperature for 2 hours, the resulting mixture was placed in an autoclave and heated at 180°C for 7 days; the solid product was recovered by centrifugation and repeatedly washed with distilled water; after drying overnight, it was calcined in air at 550°C for 8 hours to remove the organic template; the calcined sample was ion exchanged twice with a 1.0M NH4NO3 aqueous solution at 80°C for 4 hours to obtain NH4 + The sample in the H form was then converted to the H form of UZM-35 by calcining at 550 °C for 4 hours;
[0090] 2) Impregnation method: 99 mg of Ni(NO3)2·6H2O was dissolved in 20 ml of ethanol solvent, 200 mg of the prepared UZM-35 molecular sieve material was added, and the mixture was stirred for 1 hour to uniformly disperse. The ethanol was removed using a rotary evaporator at 50°C, and the mixture was dried in an oven at 80°C.
[0091] 3) The sample obtained in step 2) was ground into a powder, and a certain amount of the powder was weighed into a quartz tube and reduced in a mixed atmosphere of hydrogen and argon. The temperature was raised to 300° C. at a heating rate of 2° C. / min, maintained for 2 hours, and then cooled to room temperature to obtain a 6-Ni / UZM-35 supported catalyst.
[0092] Example 2
[0093] Application of a Ni / UZM-35 supported catalyst in the catalytic cracking of methane to produce hydrogen.
[0094] The catalyst prepared in Example 1 was applied to a methane catalytic cracking reaction, and the steps were as follows:
[0095] 1) Take a quartz tube, load it with 20 mg of catalyst, plug both ends with an appropriate amount of quartz wool, and place the quartz tube horizontally in a tube furnace;
[0096] 2) High-purity H2 was introduced and the temperature was raised to 600°C at a heating rate of 10°C / min, and the temperature was maintained for 2 hours. Then, N2 was replaced and the temperature was raised to the required temperature to start the reaction;
[0097] 3) After the temperature stabilizes, switch to the feed gas CH4 at a gas flow rate of 40 mL / min;
[0098] 4) Connect to an online gas chromatograph and collect data after the reaction starts;
[0099] 5) After the reaction is completed, stop heating and replace the feed gas with high-purity N2 until the temperature drops to the specified temperature. Then take out the reaction tube and the catalyst sample after the reaction for characterization analysis.
[0100] After testing, see Figure 2 As shown, the Ni / UZM-35 catalyst of the present invention has high catalytic performance, and the methane conversion rate is ≥85.9%. Therefore, it can be seen that the catalyst has excellent catalytic performance.
[0101] Comparative Example 7
[0102] The catalyst prepared in Comparative Example 1 was applied to a methane catalytic cracking reaction, and the application process was the same as in Example 2.
[0103] See also Figure 2 As shown, after the catalyst of Comparative Example 1 is used, the methane conversion rate is up to 75.6%.
[0104] It can be seen from this that the catalytic performance of the catalyst used in this comparative example is significantly lower than that of Example 2.
[0105] Comparative Example 8
[0106] The catalyst prepared in Comparative Example 2 was applied to a methane catalytic cracking reaction, and the process was the same as in Example 2.
[0107] See also Figure 2 As shown, after the catalyst of Comparative Example 2 is used, the methane conversion rate is as high as 76.7%.
[0108] It can be seen from this that the catalytic performance of the catalyst used in this comparative example is significantly lower than that of Example 2.
[0109] Comparative Example 9
[0110] The catalyst prepared in Comparative Example 3 was applied to a methane catalytic cracking reaction, and the process was the same as in Example 2.
[0111] See also Figure 2 As shown, after the catalyst of Comparative Example 3 is used, the methane conversion rate is up to 50.7%.
[0112] It can be seen from this that the catalytic performance of the catalyst used in this comparative example is significantly lower than that of Example 2.
[0113] Comparative Example 10
[0114] The catalyst prepared in Comparative Example 4 was applied to a methane catalytic cracking reaction, and the process was the same as in Example 2.
[0115] See also Figure 2 As shown, after the catalyst of Comparative Example 4 is used, the methane conversion rate is as high as 83.7%.
[0116] It can be seen from this that the catalytic performance of the catalyst used in this comparative example is significantly lower than that of Example 2.
[0117] Comparative Example 11
[0118] The catalyst prepared in Comparative Example 5 was applied to a methane catalytic cracking reaction, and the process was the same as in Example 2.
[0119] See also Figure 2 As shown, after the catalyst of Comparative Example 5 is used, the methane conversion rate is as high as 84.8%.
[0120] It can be seen from this that the catalytic performance of the catalyst used in this comparative example is significantly lower than that of Example 2.
[0121] Comparative Example 12
[0122] The catalyst prepared in Comparative Example 6 was applied to a methane catalytic cracking reaction, and the process was the same as in Example 2.
[0123] See also Figure 2As shown, after the catalyst of Comparative Example 6 is used, the methane conversion rate is as high as 76.2%.
[0124] It can be seen from this that the catalytic performance of the catalyst used in this comparative example is significantly lower than that of Example 2.
[0125] Comparative Example 13
[0126] Example 2 was repeated except that the reaction temperature was 350°C.
[0127] See also Figure 3 As shown, when the reaction temperature is 350° C., the methane conversion rate is the highest at 45.3%. The catalytic performance of the catalyst is significantly lower than that of Example 2.
[0128] It can be seen from this that in the catalyst preparation method steps of the present application, the reaction temperature has a huge impact on the performance of the catalyst.
[0129] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention and are not intended to limit the embodiments of the present invention. Those skilled in the art will appreciate that other variations or modifications based on the above description are possible. It is not possible to enumerate all embodiments here. Any obvious variations or modifications arising from the technical solution of the present invention remain within the scope of protection of the present invention.
Claims
1. A M / UZM-35 supported catalyst, characterized in that It is composed of UZM-35 carrier and metal Ni, Fe and other nanoparticles loaded on the UZM-35 carrier; The loading amount of the metal nanoparticles is 5.0-30.0 wt.%; The UZM-35 carrier is a plate-like structure.
2. A method for preparing a M / UZM-35 supported catalyst as claimed in claim 1, characterized in that: The steps include: 1) Mixing an aluminum source, a silicon source, and a template, then adding an aqueous solution of KOH or NaOH, stirring at room temperature to obtain a reaction solution; transferring the reaction solution into an autoclave, heating at 150-180°C for 4-10 days; recovering the solid product by centrifugation, washing it with distilled water, and drying it; then calcining it in air at 400-600°C for 4-10 hours; ion-exchanging the calcined sample in an aqueous solution of NH4NO3 at 50-100°C for 1-3 times, each time for 3-7 hours, to obtain NH4 + The sample is in the form of H-type; and then calcined at 400-600 ° C for 4-6 hours to obtain the UZM-35 molecular sieve in the form of H-type; 2) dissolving the metal precursor containing M in an appropriate amount of ethanol solvent, adding the H-form UZM-35 molecular sieve obtained in step 1), and stirring to uniformly disperse it; 3) removing ethanol using a rotary evaporator and drying in an oven to obtain a sample; 4) Grinding the sample obtained in step 3) into powder, weighing the powder into a quartz tube, and reducing it in a mixed atmosphere of hydrogen and argon to obtain the M / UZM-35 supported catalyst.
3. The method for preparing the M / UZM-35 supported catalyst according to claim 2, wherein: In step 1), the aluminum source is one or more of aluminum hydroxide, sodium aluminate, aluminum nitrate, aluminum chloride and aluminum isopropoxide; the silicon source is one or more of silicon dioxide, silica sol and tetraethyl orthosilicate; and the template is one or more of methyldipropylammonium hydroxide, tetrapropylammonium hydroxide and tetraethylammonium hydroxide.
4. The method for preparing the M / UZM-35 supported catalyst according to claim 2, wherein: In step 1), the stirring time at room temperature is 1-4 hours.
5. The method for preparing the M / UZM-35 supported catalyst according to claim 2, wherein: In step 1), the concentration of the aqueous solution of NH4NO3 is 0.8-1.2M.
6. The method for preparing the M / UZM-35 supported catalyst according to claim 2, wherein: In step 1), the final composition of the reaction solution is (4-6)DMDPAOH·xK2O·(1-x)Na2O·yAl2O3·(5-20)SiO2·(100-200)H2O, wherein 0≤x≤1 and 0≤y≤1.
7. The method for preparing the M / UZM-35 supported catalyst according to claim 2, wherein: In step 2), the stirring time is 1-2 hours; preferably, the metal precursor containing M is selected from one of nickel nitrate, nickel chloride, ferric nitrate and ferric chloride.
8. The method for preparing the M / UZM-35 supported catalyst according to claim 2, wherein: In step 3), the operating temperature of the rotary evaporator is 40-70°C; the drying temperature of the oven is 70-90°C.
9. The method for preparing the M / UZM-35 supported catalyst according to claim 2, wherein: In step 4), the heating rate during the reduction treatment is 10-30°C / min, the reduction treatment temperature is 500-800°C, and the reduction treatment time is 3-4 hours; the hydrogen content in the hydrogen and argon mixed atmosphere is 2-20 vol%.
10. Application of a M / UZM-35 supported catalyst in the catalytic cracking of methane to produce hydrogen; Preferably, the reaction temperature of the methane catalytic cracking reaction to produce hydrogen is 500-800°C.