KR102410241B1 - solid acid catalyst of metal oxide for hydrogen production using liquid-phase plasma reaction and solid acid catalyst of metal oxide manufactured thereby - Google Patents

Abstract

The present invention relates to a method for producing a metal oxide solid acid catalyst for hydrogen generation by a liquid phase plasma reaction and a metal oxide solid acid catalyst prepared thereby, and more particularly, to a method for producing a metal oxide solid acid catalyst for hydrogen generation by a liquid phase plasma reaction. The present invention relates to a method for preparing a metal oxide solid acid catalyst capable of increasing hydrogen production efficiency, and to a metal oxide solid acid catalyst prepared thereby.

Description

A method of manufacturing a metal oxide solid acid catalyst for hydrogen production by liquid-phase plasma reaction and a metal oxide solid acid catalyst manufactured thereby thereby}

The present invention relates to a method for producing a metal oxide solid acid catalyst for hydrogen generation by a liquid phase plasma reaction and a metal oxide solid acid catalyst prepared thereby, and more particularly, to a method for producing a metal oxide solid acid catalyst for hydrogen generation by a liquid phase plasma reaction. The present invention relates to a method for preparing a metal oxide solid acid catalyst capable of increasing hydrogen production efficiency, and to a metal oxide solid acid catalyst prepared thereby.

Although modern society has achieved a high degree of industrialization, it is facing serious environmental problems such as acceleration of global warming and climate change due to excessive use of fossil fuels. For this reason, interest in R&D on clean energy manufacturing technology to replace fossil fuels is being drawn. So far, hydrogen energy has been attracting attention as the only viable alternative to solving environmental and energy problems.

Hydrogen energy is attracting attention as a future energy to replace fossil fuels with clean energy. As climate change becomes more serious, ways to reduce the use of fossil fuels that generate carbon dioxide are being sought. For this, it is absolutely necessary to expand the use of hydrogen energy. In order to solve future energy problems, it is very important to secure more efficient hydrogen energy production technology.

In order to use hydrogen as energy, it is important to produce it not only in an economical way but also in a way that minimizes the impact on the environment. Hydrogen production methods are divided into production through fossil fuel reforming, which is a traditional method, and production using renewable methods, biomass and water. Hydrogen production using fossil fuels is possible through thermochemical methods such as wet reforming, autothermal reforming, partial oxidation and gasification. In order to use it as a clean energy source, it is necessary to separately capture carbon dioxide along with hydrogen production.

Hydrogen is firmly recognized as a future clean energy that will replace fossil fuels and solve environmental pollution. However, most of the hydrogen production still depends on steam reforming using fossil fuels or natural gas. This method should solve this problem because carbon dioxide is emitted during the production process.

For this reason, interest in research on hydrogen production processes that do not emit carbon dioxide has recently been attracting attention. Among them, hydrogen production by water electrolysis or photolysis technology can be evaluated as a method of producing clean hydrogen when electrical energy used in the reaction is obtained from renewable energy. However, this method has a limitation in that the hydrogen productivity is low. Therefore, a more environmentally friendly and mass-produced method of hydrogen has become the focus of major research.

Plasma is called the fourth phase and is generated by high voltage discharge by various methods. The strong thermal energy and light energy generated by plasma discharge can cause various chemical reactions. Plasma is typically a plasma generated in a gas phase. It is commonly applied to create fine crystals for thin films and semiconductors. In addition, it is applied in various fields.

On the other hand, the technology of generating plasma directly in the liquid phase and using it is not generalized. Liquid-phase plasma (LPP) is generated by a high voltage that is emitted directly from a liquid reactant. Plasma generated in water by high voltage discharge emits strong and dense ultraviolet and visible light to generate many active species. In addition, it emits thermal energy that instantaneously reaches a high temperature of 1000°C. This thermal energy causes various chemical reactions to occur. Liquid plasma simultaneously induces an electric field, strong ultraviolet rays, high-pressure shock waves, various free radical generation and ozone generation effects. This effect can destroy harmful chemicals and eliminate microorganisms or bacteria in the liquid.

Recently, as disclosed in Korean Patent Registration No. 10-1814128, a technique for generating hydrogen by decomposing water by generating plasma in water in which a photocatalyst is present is known.

The patented technology uses titanium dioxide (TiO ₂ ), which is a kind of metal oxide, as a catalyst.

Since the titanium dioxide catalyst exhibits photocatalytic activity only in ultraviolet light, it is impossible to effectively use plasma that emits ultraviolet light and visible light at the same time. In addition, due to the nature of the photocatalyst, it has no activity at all with respect to thermal energy generated by plasma radiation.

Republic of Korea Patent No. 10-1814128: Hydrogen production method using liquid plasma and photocatalyst

The present invention was created to improve the above problems, and is activated by thermal energy generated in plasma to further increase the production efficiency of hydrogen compared to a photocatalyst, and a method for producing a metal oxide solid acid catalyst and a metal oxide solid prepared thereby It is an object to provide an acid catalyst.

The method for producing a metal oxide solid acid catalyst for hydrogen generation by liquid-phase plasma reaction of the present invention for achieving the above object is a light bulb containing a sodium (Na) source, an aluminum (Al) source, and a silicon (Si) source A first step of synthesizing a solution; a second step of heat-treating the precursor solution in a reaction tank; a third step of removing the supernatant from the contents of the reactor and separating the precipitate; a fourth step of drying the precipitate and calcining to obtain a crystalline powder; a fifth step of adding and stirring the crystalline powder to a mixed solution of ammonium nitrate and aluminum hydroxide in distilled water; and a sixth step of separating the solid product from the mixed solution and calcining to produce a Na-Al-Si-based metal oxide.

The Na-Al-Si-based metal oxide is supported with hydrogen ions.

The first step is a) dissolving sodium hydroxide, sodium aluminate, and colloidal silicic acid in distilled water sequentially to obtain a first solution, b) aging the first solution at room temperature for 12 to 36 hours; c) dissolving tetrapropylammonium bromide in alcohol to obtain a second solution, d) dissolving sodium hydroxide, sodium aluminate, and colloidal silicic acid in distilled water in sequence, and then adding the aged first solution to the third solution and e) mixing the second solution with the third solution to obtain the precursor solution.

In the second step, heat treatment is performed at 90 to 110° C. for 2 to 8 hours.

The fourth step is calcined at 500 to 600° C. for 5 to 15 hours.

The fifth step is stirred for 12 to 36 hours at 50 to 70 ℃.

And the metal oxide solid acid catalyst for hydrogen generation by liquid-phase plasma reaction of the present invention for achieving the above object is a Na-Al-Si-based metal oxide catalyst prepared by the above manufacturing method, and the thermal energy of plasma generated in the liquid activated to produce hydrogen.

As described above, the present invention provides a method for preparing a metal oxide solid acid catalyst to which various types of metals are bonded.

The metal oxide solid acid catalyst of the present invention can generate hydrogen by causing a catalytic decomposition reaction by thermal energy generated by plasma in a liquid. This can increase the hydrogen production efficiency compared to the hydrogen production reaction using a photocatalyst such as titanium dioxide.

Therefore, the present invention can overcome the problem of the titanium dioxide (TiO ₂ ) catalyst, which is activated only by light in the ultraviolet region, and thus can secure a more efficient hydrogen energy production technology.

1 is a configuration diagram schematically showing a liquid phase plasma reactor for generating hydrogen using a metal oxide solid acid catalyst of the present invention;
Figure 2 is a graph showing the X-ray diffraction (X-ray diffraction; XRD) pattern of the metal oxide solid acid catalyst,
3 is a scanning electron microscope (SEM) image of a metal oxide solid acid catalyst;
Figure 4 is a graph showing the energy dispersive X-ray spectroscopy (EDX) results,
5 is a graph showing the nitrogen adsorption isotherm of the metal oxide solid acid catalyst,
6 is a graph showing the ammonia temperature rise desorption curve of the metal oxide solid acid catalyst,
7 is an infrared spectroscopy graph measured after adsorbing pyridine to a metal oxide solid acid catalyst;
8 is a graph showing the generation rate of hydrogen during liquid phase plasma reaction according to the conditions for adding a metal oxide solid acid catalyst, for adding a TiO ₂ catalyst, and for not adding a catalyst.

Hereinafter, a method for producing a metal oxide solid acid catalyst for hydrogen generation by liquid-phase plasma reaction according to a preferred embodiment of the present invention and a metal oxide solid acid catalyst prepared thereby will be described.

A method for producing a metal oxide solid acid catalyst for hydrogen generation by liquid-phase plasma reaction according to an embodiment of the present invention comprises a first step of synthesizing a precursor solution, a second step of heat-treating the precursor solution in a reaction tank, and The third step of removing the supernatant and separating the precipitate, the fourth step of drying the precipitate and calcining to obtain a crystalline powder, and adding the crystalline powder to a mixed solution in which ammonium nitrate and aluminum hydroxide are dissolved in distilled water and a fifth step of stirring the mixture, and a sixth step of separating the solid product from the mixed solution and calcining to produce a Na-Al-Si-based metal oxide. Let's look at each step in detail.

1. Step 1

In the first step, a precursor solution is synthesized. The precursor solution contains a sodium (Na) source, an aluminum (Al) source, and a silicon (Si) source.

As a sodium (Na) source, sodium hydroxide (NaOH) can be used. And sodium aluminate (NaAlO ₂ ) may be used as an aluminum (Al) source. And colloidal silica may be used as a silicon (Si) source.

Specifically, to synthesize the precursor solution, a) dissolving sodium hydroxide, sodium aluminate, and colloidal silicic acid in distilled water sequentially to obtain a first solution, b) aging the first solution at room temperature for 12 to 36 hours and c) dissolving tetrapropylammonium bromide in alcohol to obtain a second solution, d) dissolving sodium hydroxide, sodium aluminate, and colloidal silicic acid in distilled water in sequence, and then adding the aged first solution to the third obtaining a solution, and e) mixing the third solution with the second solution to obtain a precursor solution.

First, a first solution is prepared.

Sodium hydroxide is poured into distilled water and dissolved by stirring, and then sodium aluminate is injected into the solution and stirred to dissolve it. Then, colloidal silicic acid is injected into this solution and dissolved by stirring. In this way, sodium hydroxide, sodium aluminate, and colloidal silicic acid are sequentially injected and dissolved in distilled water to obtain a first solution.

Next, the first solution is aged. As an example of aging, it may be aged for 12 to 36 hours at room temperature (20 to 30° C.).

Next, a second solution is prepared.

The second solution is obtained by dissolving tetra propyl ammonium bromide in alcohol. As the alcohol, iso-propanol may be used. A second solution obtained by dissolving tetrapropylammonium bromide in alcohol serves as a template.

Next, a third solution is prepared.

A sodium (Na) source, an aluminum (Al) source, and a silicon (Si) source are additionally used to prepare the third solution. For example, sodium hydroxide is injected into distilled water and dissolved by stirring, then sodium aluminate is injected into this solution and dissolved by stirring, then colloidal silicic acid is injected into this solution and stirred to dissolve to obtain an additional solution. Then, the first solution aged in the additional solution is injected and stirred for 30 to 90 minutes to obtain a third solution. The additional solution and the first solution may be mixed in a ratio of 1:0.1 to 0.5 by weight.

Next, a precursor solution is obtained by mixing the second solution with the third solution. The third solution and the second solution may be mixed in a ratio of 1:0.05 to 0.2 by weight.

2. Step 2

The prepared precursor solution is put into a reaction tank and heat-treated.

A conventional autoclave may be used as the reactor. After adding the precursor solution, the reactor is sealed and aged at room temperature for one day. Then, the reaction tank is heated and reacted by heat treatment at 90 to 110° C. for 2 to 8 hours.

3. Step 3

The supernatant is removed from the contents of the reactor and the precipitate is separated.

To this end, when the second step is completed, the heating of the reactor is stopped and left in the reactor for one day so that the generated solids can be precipitated. After standing for one day, the supernatant of the reaction tank can be removed and the precipitate from the lower layer can be separated. At this time, the precipitate has a gel form.

In order to wash the precipitate with distilled water, the supernatant is removed, the precipitate remaining in the reaction tank is filled with distilled water, stirred for 3 to 7 hours, left still for 6 to 12 hours, and then the supernatant is removed again. Then, the reaction tank may be filled with distilled water again, stirred for 3 to 7 hours, allowed to stand for 6 to 12 hours, and then the precipitate may be finally separated and collected.

4. Step 4

The collected precipitate is dried in an oven and calcined to obtain a crystalline powder.

Drying can be carried out in an electric furnace. For example, the dried precipitate may be put into an electric furnace and calcined at 500 to 600° C. for 5 to 15 hours.

Organic matter and by-products are removed by burning through calcination, and a crystalline powder can be obtained. The crystalline powder is a Na-Al-Si-based metal oxide in which Na, Al, and Si are bonded.

5. Step 5

Prepare a mixed solution by dissolving ammonium nitrate and aluminum hydroxide in distilled water. Then, the crystalline powder is added to the mixed solution and stirred at 50 to 70° C. for one day.

Ammonium nitrate is used to replace cations in the crystalline powder with hydrogen ions, and aluminum hydroxide is used to increase the aluminum content of the crystalline powder.

6. Step 6

In the fifth step, the stirred solution is filtered to separate the solid product in the mixed solution.

The separated solid product is washed with distilled water, dried in an oven, and then put into an electric furnace and calcined. For example, the dried solid product may be calcined at 500 to 600° C. for 5 to 15 hours. After sintering is completed, it is cooled slowly and then pulverized to finally obtain a Na-Al-Si-based metal oxide in powder form. This Na-Al-Si-based metal oxide in powder form is a solid acid catalyst of the present invention. Such a Na-Al-Si-based metal oxide may be represented by the following chemical formula.

Na _α Al _β Si _γ O _δ

In the above formula, based on α = 1, β = 0.1 to 3.2, γ = 0.3 to 5, and δ = 20 to 100.

In particular, the Na-Al-Si-based metal oxide on which hydrogen ions are supported can be expressed as follows.

H ⁺ /Na _α Al _β Si _γ O _δ

The metal oxide solid acid catalyst of the present invention prepared as described above is activated by thermal energy generated by liquid-phase plasma radiation to decompose liquid-phase reactants, so that hydrogen generation efficiency can be increased through plasma reaction. Liquid-phase plasma reactions that generate high-energy plasmas in liquids can generate thermal energy in liquids with various active species.

An example of a liquid phase plasma reactor for generating hydrogen using the metal oxide solid acid catalyst of the present invention is shown in FIG. 1 .

Referring to FIG. 1 , the liquid-phase plasma reactor includes a cylindrical reactor 10 , a cooling tank 20 for circulating the liquid in the reactor 10 to maintain a constant temperature, and a pair of electrodes installed in the reactor 10 . 30 and a power supply (bipolar pulse power supply) 35 for supplying power to the electrode 30 .

The electrode 30 is made of a tungsten material, and the outside of the electrode 30 is covered with an insulator made of a ceramic material. The distance between the two electrodes 30 may be maintained at about 0.2 to 0.5 mm.

When power is supplied to the electrode 30 through the power supply 35, plasma is generated in the liquid by electric discharge. In order to prevent the temperature rise of the liquid when plasma is generated by electric discharge, it is preferable to circulate the liquid to the cooling tank 20 using a circulation pump to maintain the temperature of the liquid at 18 to 25°C. The reactor 10 and the cooling tank 20 are connected by circulation lines 11 and 13 .

When power is supplied, it is preferable to supply power as a pulse (pulse width 3 to 5 μs) rather than continuously supplying power to the electrodes. When power is supplied as a pulse, it is possible to reduce the dissolution of electrode components by inhibiting the melting of the electrode exposed to the suspension.

Conditions of power supplied to the electrode to generate plasma may be a voltage of 230 to 250V, a pulse width of 3 to 5 ㎲, and a frequency of 25 to 30KHz.

And in the liquid-phase plasma reactor shown in FIG. 1, a flow controller (MFC) 45 for introducing nitrogen gas stored in the nitrogen tank 40 into the reactor in order to analyze the gas product generated inside the reactor 10, and the reactor A gas chromatograph (GC) 50 for analyzing the gas flowing out from 10 is installed.

The metal oxide solid acid catalyst of the present invention is added to the liquid accommodated in the reactor. For example, 0.001 to 1 part by weight of the metal oxide solid acid catalyst is added with respect to 100 parts by weight of the liquid and stirred to uniformly disperse the catalyst in the liquid. Water or a hydrocarbon compound may be used as the liquid for generating hydrogen.

When plasma is generated in a liquid to which a metal oxide solid acid catalyst is added, various active species (H·, OH·, O·, H ₂ O ₂ , O ₂ ⁻ , O ₃ , etc.) are generated, and these active species are hydrogen promotes the creation In addition, when plasma is generated, the metal oxide solid acid catalyst is activated by high-temperature thermal energy to increase the hydrogen production efficiency.

Hereinafter, the present invention will be described with reference to an experimental example. However, the following experimental examples are for explaining the present invention in detail, and the scope of the present invention is not limited to the following experimental examples.

(Preparation of metal oxide solid acid catalyst)

0.22 mol of sodium hydroxide was injected into 200 mL of distilled water and dissolved by stirring, then 0.04 mol of sodium aluminate was injected into this solution and dissolved by stirring, and 0.26 mol of colloidal silicic acid (SiO ₂ concentration 40wt%) was added to this solution. The first solution was obtained by pouring and stirring to dissolve. The first solution was aged at 25° C. for 24 hours.

Then, 0.03 mol of tetrapropylammonium bromide was injected into 100 mL of iso-propanol to obtain a second solution.

Then, 0.43 mol of sodium hydroxide was injected into 500 mL of distilled water and dissolved by stirring. Then, 0.23 mol of sodium aluminate was injected into this solution and dissolved by stirring, and then 0.12 mol of colloidal silicic acid (SiO ₂ concentration 40wt%) in this solution. After injecting and stirring, the aged first solution was added thereto and stirred for 1 hour to obtain a third solution.

Then, after mixing the second solution with the third solution, it was put into an autoclave, aged at 25° C. for 24 hours, and then heated to 100° C. and heat-treated for 5 hours. Then, the heating of the reactor was stopped, left still for one day, the supernatant was removed, filled with distilled water, stirred for 5 hours, left still for 10 hours, then the supernatant was removed again, filled with distilled water, stirred for 5 hours, and then stirred for 5 hours for 10 hours After standing for a while, the precipitate was separated and collected. The toweled precipitate was put in an oven, dried at 120°C for two days, and then calcined in an electric furnace at 550°C for 10 hours to obtain a crystalline powder.

A crystalline powder was added to a stirred mixture of 0.5 mol of ammonium nitrate and 0.1 mol of aluminum hydroxide in 500 mL of distilled water, stirred at 60° C. for one day, and then filtered to separate a solid product. The solid product was washed with distilled water, put in an oven, dried at 120° C. for two days, and then calcined in an electric furnace at 550° C. for 10 hours, cooled slowly, and then pulverized to prepare a powdery metal oxide solid acid catalyst.

<Experimental Example 1: X-ray diffraction analysis>

2 shows the results of X-ray diffraction analysis of the metal oxide solid acid catalyst. From the fact that the intensity of the characteristic peak of the XRD pattern was large and the peak was sharply formed, it was found that the catalyst had a good crystalline structure.

<Experimental Example 2: Scanning Electron Microscope (SEM) Image and Energy Dispersive X-ray Spectroscopy (EDX) Analysis >

3 shows a scanning electron microscope (SEM) image of the metal oxide solid acid catalyst. The crystals of the metal oxide solid acid catalyst had a hexagonal shape. The size of the crystals was small and uniform, about 0.5 μm. The surface of the crystal was smooth and evenly dispersed without agglomeration.

4 is an energy dispersive X-ray spectroscopy (EDX) analysis result measured to confirm the elemental composition of the metal oxide solid acid catalyst. The main metal components of the metal oxide solid acid catalyst were Si and Al, and these metal elements were combined with oxygen to form crystalline aluminosilicate. Crystalline aluminosilicate has regular pores and has adsorption and molecular sieve functions. In addition, crystalline aluminosilicate is a solid acid material that exhibits acidity depending on the content of Al and H ⁺ ions.

<Experimental Example 3: Nitrogen adsorption isotherm analysis>

5 shows the nitrogen adsorption isotherm of the metal oxide solid acid catalyst. 5, 'ADS' is an adsorption curve, and 'DES' is a desorption curve.

Referring to FIG. 5 , the nitrogen adsorption isotherm shows a typical form of an adsorption isotherm of a porous material having micropores. The adsorption isotherm of the metal oxide solid acid catalyst showed a large amount of adsorption and confirmed that the material had a micropore structure in which small pores were evenly distributed. The BET surface area obtained from the nitrogen adsorption isotherm result was very large as 708.0 m ² /g.

<Experimental Example 4: Ammonia elevated temperature desorption characteristics analysis>

6 shows the ammonia temperature programmed desorption (NH ₃ -TPD) curve of the metal oxide solid acid catalyst.

Referring to FIG. 6 , the NH ₃ -TPD curve of the metal oxide solid acid catalyst showed only one peak, which seems to indicate that the desorption of the physisorbed ammonia and the desorption of the chemisorbed ammonia overlap. The amount of acid sites measured from the elevated temperature desorption curve of ammonia was measured to be about 3.5 mmol/g. Since the strong acid strength and many acid sites of the metal oxide solid acid catalyst act as catalyst active sites in the plasma decomposition reaction, it was expected to be advantageous for the decomposition reaction.

<Experimental Example 5: Infrared Spectroscopy Experiment>

7 shows an infrared spectroscopy spectrum measured after adsorbing pyridine to a metal oxide solid acid catalyst. The hydrogen ion exchanged solid acid catalyst becomes acidic. The acidity of the solid acid catalyst can be measured by the ammonia desorption method, but the type of acid site cannot be distinguished. Using the fact that the absorption band of the pyridine adsorbed to the acid site differs depending on the type of the acid site, the type of the acid site was determined from the infrared spectrum of the pyridine adsorbed to the solid acid catalyst.

Among the infrared absorption bands of pyridine adsorbed to the acid site of the solid acid catalyst, the absorption band at 1440 to 1450 cm ^-1 indicates very strong hydrogen bonding, and the absorption band at 1485 to 1490 cm ^-1 indicates weak hydrogen bonding, and at 1580 to 1600 cm ^-1 The resulting absorption band is caused by strongly hydrogen-bonded pyridines. This is because pyridine is adsorbed and appears when the surface of the solid acid catalyst is made of hydrogen bonding, so when such an infrared absorption band is detected, it is disproved that the surface of the solid acid catalyst is hydrogen bonded.

As can be seen in FIG. 7 , infrared absorption bands appeared at 1447 cm ^-1 and 1485 cm ^-1 . The band at 1447 cm ^-1 shows very strong hydrogen bonding pyridine, and the absorption band at 1485 cm ^-1 shows weak hydrogen bonding as well. Therefore, it is suggested that hydrogen ions are located on the surface of the solid acid catalyst, which is caused by hydrogen ion exchange.

<Experimental Example 6: Hydrogen Generation Experiment>

A hydrogen production experiment was performed using the liquid-phase plasma reactor of FIG. 1 .

A suspension in which 0.3 g of a metal oxide solid acid catalyst was added and dispersed in 200 mL of an ethanol aqueous solution having a concentration of 10 wt% was injected into the reactor, and then discharged for 60 minutes under the conditions of a voltage of 240 V, a frequency of 25 kHz, and a pulse width of 6 μs to generate plasma.

In addition, TiO ₂ (P25, Degussa) catalyst was added and the experiment was carried out under the condition that the catalyst was not added, respectively.

8 shows the hydrogen production rate according to the metal oxide solid acid catalyst addition condition, the TiO ₂ catalyst is added, and the catalyst is not added.

Referring to FIG. 8 , it was confirmed that a small amount of hydrogen was generated by the liquid phase plasma reaction even if no catalyst was added. This is because, even in the absence of a catalyst, various active species (H·, OH·, O·, H ₂ O ₂ , O ₂ ⁻ , O ₃ , etc.) are generated in solution by plasma, and these react with reactants to cause hydrogen production . In addition, the strong energy of plasma appears to be the result of direct decomposition of water.

When a commercially used TiO ₂ catalyst was added, it was found that the hydrogen production rate was slightly increased. On the other hand, when the metal oxide solid acid catalyst was added, the hydrogen production rate was significantly increased compared to the case where the TiO ₂ catalyst was added.

As mentioned above, although the present invention has been described with reference to one embodiment, it will be understood that this is only an example, and that those skilled in the art may make various modifications and equivalent embodiments therefrom. Accordingly, the true protection scope of the present invention should be defined only by the appended claims.

10: reactor 20: cooling bath
30: electrode 35: power supply

Claims (7)

A first step of synthesizing a precursor solution containing a sodium (Na) source, an aluminum (Al) source, and a silicon (Si) source;
a second step of heat-treating the precursor solution in a reaction tank;
a third step of removing the supernatant from the contents of the reactor and separating the precipitate;
a fourth step of drying the precipitate and calcining to obtain a crystalline powder;
a fifth step of adding and stirring the crystalline powder to a mixed solution of ammonium nitrate and aluminum hydroxide in distilled water;
A method for producing a metal oxide solid acid catalyst for hydrogen production by liquid-phase plasma reaction, comprising: a sixth step of separating a solid product from the mixed solution and calcining to produce a Na-Al-Si-based metal oxide . The method of claim 1, wherein the Na-Al-Si-based metal oxide has hydrogen ions supported thereon. The method of claim 1, wherein the first step comprises: a) dissolving sodium hydroxide, sodium aluminate, and colloidal silicic acid in distilled water sequentially to obtain a first solution; b) the first solution is heated at room temperature for 12 to 36 hours. Aging for a while, c) dissolving tetrapropylammonium bromide in alcohol to obtain a second solution, d) dissolving sodium hydroxide, sodium aluminate, and colloidal silicic acid in distilled water in sequence, and then aging the first solution Metal oxide for hydrogen generation by liquid-phase plasma reaction, characterized in that it comprises the steps of obtaining a third solution by adding and e) mixing the second solution with the third solution to obtain the precursor solution A method for preparing a solid acid catalyst. The method of claim 1, wherein the second step is heat treatment at 90 to 110° C. for 2 to 8 hours. The method of claim 1, wherein the fourth step is calcined at 500 to 600° C. for 5 to 15 hours. The method of claim 1, wherein in the fifth step, stirring is performed at 50 to 70° C. for 12 to 36 hours. As a Na-Al-Si-based metal oxide catalyst prepared by the method of any one of claims 1 to 6, it is activated by thermal energy of plasma generated in a liquid to generate hydrogen. Metal oxide solid acid catalyst for hydrogen production by

Images