KR102687682B1 - Catalyst for Dehydrogenation Reaction Based on LOHC and Method for Preparing the Same - Google Patents

Abstract

The present invention relates to a catalyst for a dehydrogenation reaction based on a liquid organic hydrogen carrier and a method for manufacturing the same. More specifically, the present invention relates to a liquid organic hydrogen carrier-based catalyst that can efficiently dehydrogenate hydrogen from a liquid organic hydrogen carrier by introducing a Joule heating method. It relates to a catalyst for dehydrogenation reaction and a method for producing the same.

Description

Liquid organic hydrogen carrier-based dehydrogenation reaction catalyst and method for preparing the same {Catalyst for Dehydrogenation Reaction Based on LOHC and Method for Preparing the Same}

The present invention relates to a liquid organic hydrogen carrier-based dehydrogenation reaction catalyst and a manufacturing method thereof. More specifically, the present invention relates to a liquid organic hydrogen carrier-based dehydrogenation reaction catalyst that can efficiently dehydrogenate hydrogen from a liquid organic hydrogen carrier by introducing a Joule heating method. It relates to a catalyst for hydrogen carrier-based dehydrogenation reaction and a method for producing the same.

As environmental pollution problems such as decreasing reserves of fossil fuels, pollutants generated during combustion, and global warming caused by carbon dioxide are becoming more serious, global interest in and demand for the development of alternative energy is explosively increasing.

As alternative energy sources, new and renewable energies such as wind power, tidal power, geothermal energy, hydrogen energy, and solar energy are attracting attention, but each energy source has its own pros and cons. It is difficult to smoothly demand and supply renewable energy due to the instability of energy sources depending on time and the natural environment. Therefore, in order to effectively replace conventional fossil fuels, technology for storing and supplying surplus energy is needed to ensure a stable supply of energy. development is needed.

In this regard, hydrogen energy is (i) the most energy efficient per unit mass, (ii) combustion produces only water and no other harmful by-products, and (iii) water, the main source of hydrogen, is abundant in nature and can be used It is receiving particular attention because it is advantageous in terms of reuse since it is converted to water afterward, and (iv) it is suitable for securing competitiveness in the precision industry and IT industry as a distributed power source that uses hydrogen as fuel.

Moreover, hydrogen can be produced using other renewable energies such as solar energy and wind power, and can be widely applied not only to various energy sources but also to other industrial fields (e.g., various petrochemical fields) at home and abroad. It is emerging as a key energy source of the future.

In general, research and development of hydrogen energy is largely divided into hydrogen manufacturing, transportation (transportation), and storage fields. Hydrogen has excellent energy storage ability compared to mass, but low energy storage ability compared to volume, so hydrogen can be used efficiently. Storage technology is acting as the biggest obstacle to the practical use of hydrogen energy. Therefore, research is being actively conducted on technologies to store as much hydrogen as possible in a storage medium that is as light and compact as possible and to release it efficiently.

Conventionally, a method of compressing hydrogen and storing it in a high-pressure tank was adopted, but this high-pressure storage method has a high risk of hydrogen explosion and is difficult to store in large quantities.

As an alternative to this, research is underway on various inorganic materials and inorganic-organic complexes as materials with hydrogen storage ability, but recently, reversible catalytic hydrogenation using organic materials, specifically liquid organic hydrogen carriers (LOHCs; Liquid Organic Hydrogen Carrier), has been studied. /Hydrogen storage technology by dehydrogenation reaction has been developed (Patent Documents 0001 and 0002).

LOHC technology has the advantages of being able to operate in a low pressure range and easily regenerating stored materials, and also has the advantage of handling and high energy density, which are advantages of liquid fossil fuels, making it possible to replace existing liquid fuel transportation and storage infrastructure. A practical hydrogen storage system capable of efficient transportation and storage can be provided.

In the case of conventional LOHC technology, a dehydrogenation reaction is performed using a catalyst synthesized by impregnating a noble metal catalyst into a support such as alumina or carbon. However, the catalyst prepared in this way has low dispersion of the metal catalyst that occurs in the process of applying the metal to the surface of the support, a decrease in the specific surface area of the catalyst due to agglomeration of the metal catalyst during the reaction, and physical detachment due to low adhesion between the metal catalyst and the support. There are problems such as, and because of this, catalysts manufactured by the impregnation method have low activity and physical durability.

To solve this problem, the development of a new catalyst process is necessary, but research to date has sought to improve the reaction rate through the development of a dehydrogenation reactor rather than the development of a catalyst. This is because the LOHC dehydrogenation reaction is a reaction that requires a large heat of reaction of about 64 kJ/mol H ₂ , and due to the nature of the LOHC dehydrogenation reaction, hydrogen is generated in a volume several tens of times larger than that of LOHC during the reaction, which causes LOHC dehydrogenation. This is because the issue of inhibiting the reaction rate has been highlighted due to limited heat transfer required for the reaction.

However, as the LOHC system has been actively demonstrated recently, many reactors that can overcome heat transfer issues have been demonstrated. However, dehydrogenation in the LOHC system is still performed externally due to limitations in catalyst components or durability of the catalyst. Hydrogen is desorbed by heating to activate the catalyst inside the LOHC, so a system that effectively supplies the heat energy required for the LOHC dehydrogenation reaction has not yet been disclosed (Patent Document 0003).

In particular, the liquid organic hydrogen carriers used in LOHC technology have high specific heat, so when heating the liquid organic hydrogen carrier using an external heating method, the entire liquid organic hydrogen carrier must be heated, resulting in large energy consumption and at the same time, dehydrogenation reaction temperature and the liquid organic hydrogen carrier. If the boiling points are similar, there is a problem in that the liquid organic hydrogen carrier vaporizes and the reaction efficiency decreases. In addition, since the dehydrogenation reaction that desorbs hydrogen from the liquid organic hydrogen carrier in which hydrogen is stored is an endothermic reaction, even if sufficient heat energy required for the LOHC dehydrogenation reaction is supplied from the outside, there is a limit to the temperature falling on the surface and inside the catalyst due to the endothermic reaction. There were issues with supplying more external heat than necessary or reducing the efficiency of the catalyst.

Therefore, there is a need to develop an effective technology that saves energy and has high responsiveness by selectively heating only the catalyst in the liquid organic hydrogen carrier-based dehydrogenation reaction.

US Patent No. 7901491 (Publication date: 2009.10.01) Korean Patent No. 2338162 (Announcement Date: 2021.12.10) Korean Patent No. 2332811 (Publication date: 2021.10.07)

The main purpose of the present invention is to solve the above-mentioned problems. In the liquid organic hydrogen carrier-based dehydrogenation reaction, energy is saved by selectively heating only the catalyst, and at the same time, the catalyst is activated with high responsiveness even during the endothermic reaction. The aim is to provide a catalyst for dehydrogenation reaction based on a liquid organic hydrogen carrier that can perform dehydrogenation reaction at a fast reaction rate.

Another object of the present invention is to provide a method for producing a liquid organic hydrogen carrier-based dehydrogenation catalyst that can be manufactured simply at a lower cost compared to conventional dehydrogenation catalysts while maintaining and improving catalytic activity.

In order to achieve the above object, one embodiment of the present invention is a catalyst for a dehydrogenation reaction based on a liquid organic hydrogen carrier that dehydrogenates within the liquid organic hydrogen carrier using Joule heating, where heat generation can occur due to Joule heating. A support made of a material; and a catalytically active metal supported on the support. A catalyst for the dehydrogenation reaction of a liquid organic hydrogen carrier by Joule heating is provided.

In a preferred embodiment of the present invention, the catalytically active metal may be alloyed and supported on the catalyst support by thermal shock.

In a preferred embodiment of the present invention, the catalytically active metal is platinum (Pt), iridium (Ir), osmium (Os), rhodium (Rh), ruthenium (Ru), palladium (Pd), gold (Au), and silver. (Ag), cobalt (Co), iron (Fe), nickel (Ni), manganese (Mn), copper (Cu), scandium (Sc), titanium (Ti), vanadium (V), chromium (Cr), zirconium. (Zr), yttrium (Y), niobium (Nb), molybdenum (Mo), cadmium (Cd), iridium (Ir), tin (Sn), yttrium (Y), and tungsten (W). It can be characterized as above.

In a preferred embodiment of the present invention, the catalytically active metal may be included in an amount of 0.1% by weight to 50% by weight based on the total weight of the catalyst.

In a preferred embodiment of the present invention, the catalyst support may be one or more selected from the group consisting of activated carbon material, carbon fiber, carbon tube, fullerene, carbon black, and carbide series.

In a preferred embodiment of the present invention, the catalyst support is composed of corrugate, plate, monolith, foam, fiber, granule, and mesh. It may be characterized as having a shape selected from the group.

Another embodiment of the present invention is a method for producing a catalyst for a liquid organic hydrogen carrier dehydrogenation reaction that dehydrogenates a liquid organic hydrogen carrier using Joule heating, wherein the catalyst for the liquid organic hydrogen carrier dehydrogenation reaction is formed by Joule heating. A method for producing a catalyst for dehydrogenation reaction based on a liquid organic hydrogen carrier is provided, comprising the step of supporting a catalytically active metal on a support of a material that generates heat.

In another preferred embodiment of the present invention, the catalytically active metal is supported by the steps of (a) applying the catalytically active metal to a carbon-containing catalyst support; and (b) applying a thermal shock to the catalyst support on which the catalytically active metal is applied.

In another preferred embodiment of the present invention, the thermal shock in step (b) may be characterized by applying a current of 0.1 A to 30 A and heating to a temperature of 500 ℃ to 2,500 ℃.

In another preferred embodiment of the present invention, the thermal shock in step (b) may be performed 1 to 30 times.

Another embodiment of the present invention is a method for producing hydrogen by dehydrogenation of a liquid organic hydrogen carrier, characterized in that the dehydrogenation reaction is performed by applying an electric current to the catalyst. Provides a method for producing hydrogen.

In another preferred embodiment of the present invention, the temperature of the surface of the catalyst support when the current is applied may be 500°C to 2,500°C.

The catalyst for dehydrogenation reaction based on a liquid organic hydrogen carrier according to the present invention is manufactured by alloying a previously used single-component noble metal-based catalyst with a metal that is relatively easy to obtain and inexpensive through thermal shock, thereby converting the catalyst into active ingredients. A catalyst with excellent durability can be easily manufactured at a low cost without desorption, and the particle structure of the catalytically active metal can be formed and controlled so that the specific surface area of the catalyst is not reduced, thereby improving catalytic activity.

In addition, the catalyst for dehydrogenation reaction based on a liquid organic hydrogen carrier according to the present invention is selectively and uniformly heated through Joule heating in a liquid organic hydrogen carrier with a high specific heat, so it is very advantageous for energy saving and system miniaturization, and is therefore very advantageous for various hydrogen release systems. At the same time, it can prevent the dehydrogenation efficiency of the catalyst from decreasing by suppressing the vaporization of the liquid organic hydrogen carrier, and the catalyst is formulated and present in the liquid organic hydrogen carrier to collect the catalyst in the liquid organic hydrogen carrier and It has the effect of being easy to reuse.

Figure 1 is a schematic diagram of an alloy catalyst for dehydrogenation reaction based on a liquid organic hydrogen carrier according to an embodiment of the present invention.
Figure 2 is a schematic diagram of a method for producing a catalyst for dehydrogenation reaction based on a liquid organic hydrogen carrier according to an embodiment of the present invention.
Figure 3 is a graph showing the results of measuring the dehydrogenation reaction of the liquid organic hydrogen carrier-based dehydrogenation catalyst according to Example 1 and Comparative Example 1 of the present invention.
Figure 4 is a graph showing the results of measuring the dehydrogenation reaction of the liquid organic hydrogen carrier-based dehydrogenation catalyst according to Examples 2 to 4 and Comparative Example 2 of the present invention.

The advantages and features of the present invention and methods for achieving them will become clear by referring to the embodiments described in detail below along with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below and will be implemented in various different forms. These embodiments only serve to ensure that the disclosure of the present invention is complete and that common knowledge in the technical field to which the present invention pertains is not limited. It is provided to fully inform those who have the scope of the invention, and the present invention is only defined by the scope of the claims.

In describing the present invention, if it is determined that a detailed description of related known technologies may unnecessarily obscure the gist of the present invention, the detailed description will be omitted.

When 'includes', 'has', 'consists of', 'consists of', etc. mentioned in the specification are used, other parts may be added unless 'only' is used. When a component is expressed in the singular, the plural is included unless specifically stated otherwise.

Also, in the case of a description of a positional relationship, for example, if the positional relationship between two parts is described as 'on top', 'on the top', 'on the bottom', 'next to', etc., 'right away' Unless ' or 'directly' is used, one or more other parts may be placed between the two parts. In the case of a description of a temporal relationship, for example, if a temporal relationship is described as ‘after’, ‘after’, ‘after’, ‘before’, etc., ‘immediately’ or ‘directly’ Non-consecutive cases may also be included unless ' is used.

Each feature of the various embodiments of the present invention can be combined or combined with each other, partially or entirely, and various technical interconnections and operations are possible, and each embodiment can be implemented independently of each other or together in a related relationship. It may be possible.

In general, the liquid organic hydrogen carrier-based dehydrogenation reaction proceeds in unsaturated hydrocarbon compounds with large sizes and high specific heat, such as benzene, toluene, naphthalene, and biphenyl compounds, so heat transfer in the liquid organic hydrogen carrier-based dehydrogenation reaction and mass transfer are very important. In particular, since the above unsaturated hydrocarbon compounds exist in a liquid state during the dehydrogenation reaction, the importance of heat transfer and mass transfer is more important than in the gas phase reaction, so it is very important to develop a catalyst that facilitates heat transfer and mass transfer. .

Therefore, the present invention provides a catalyst capable of Joule heating, which can perform a dehydrogenation reaction by selectively heating only the catalyst in a liquid organic hydrogen carrier-based dehydrogenation reaction, and is relatively easy to obtain and inexpensive compared to existing platinum-based catalysts. By alloying and manufacturing through thermal shock, a catalyst with excellent physical durability can be manufactured simply at a low cost, and the particle structure of the catalytically active metal can be formed and controlled so that the specific surface area of the catalyst is not reduced, thereby improving the dehydrogenation reaction. A catalyst for dehydrogenation reaction based on a liquid organic hydrogen carrier that can significantly improve catalytic activity can be provided.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the attached drawings. Figure 1 is a schematic diagram of a catalyst for a liquid organic hydrogen carrier-based dehydrogenation reaction according to an embodiment of the present invention, and Figure 2 is a schematic diagram of a catalyst for a liquid organic hydrogen carrier-based dehydrogenation reaction according to an embodiment of the present invention. This is a schematic diagram.

Referring to FIG. 1, the catalyst 100 for a liquid organic hydrogen carrier-based dehydrogenation reaction according to the present invention is a catalyst for a liquid organic hydrogen carrier-based dehydrogenation reaction that dehydrogenates within a liquid organic hydrogen carrier using Joule heating, Carbon-containing catalyst support (110); and a catalytically active metal 120 bound to the catalyst support.

The catalyst support 110 is a carbon-containing compound capable of Joule heating and can be applied without limitation, for example, activated carbon body, carbon fiber, carbon tube, fullerene, carbon black, and carbide series (tungsten carbide, silicon carbide, titanium carbide, etc.) It may be selected from the group consisting of corrugate, plate, monolith, foam, fiber, granule, and mesh for mass transfer of the catalyst. It may be a shape that becomes

The catalyst support is supported with catalytically active metal 120 alloyed on its outer circumferential surface and/or inner circumferential surface.

At this time, the catalytically active metal includes bimetallic alloy metal or multi-component high-entropy alloys, such as platinum (Pt), iridium (Ir), osmium (Os), Rhodium (Rh), ruthenium (Ru), palladium (Pd), gold (Au), silver (Ag), cobalt (Co), iron (Fe), nickel (Ni), manganese (Mn), copper (Cu), Scandium (Sc), titanium (Ti), vanadium (V), chromium (Cr), zirconium (Zr), yttrium (Y), niobium (Nb), molybdenum (Mo), cadmium (Cd), iridium (Ir), It may be two or more types selected from the group consisting of tin (Sn), yttrium (Y), and tungsten (W).

The catalytically active metal may be supported on the catalyst support in an amount of 0.1% to 50% by weight based on the total weight of the catalyst.

In addition, the liquid organic hydrogen carrier-based dehydrogenation catalyst according to the present invention may contain other metals in addition to the metals described above as catalytically active metals, and may be a binary or ternary catalyst as well as various multi-component metal catalysts.

Meanwhile, the catalytically active metal is alloyed by thermal shock, and in this process, the metal elements are melted and then strongly bound and supported on the catalyst support that supplies the heat source, resulting in high adhesion between the catalytically active metal and the catalyst support. Therefore, even during the dehydrogenation reaction by Joule heating, problems such as physical detachment of the catalytic active metal do not occur, so the catalyst activity does not decrease significantly even after long-term use, and it can be stable.

At this time, the thermal shock is preferably applied at an appropriate voltage and current value according to the resistance value of the catalyst support, and the applied current value can be adjusted to grow catalytically active metals, preferably 0.1 A to 30 A. A current corresponding to can be applied.

The time for applying the power is preferably adjusted within the range of 0.001 seconds to 10 seconds in accordance with the target dispersion degree and the size of the catalytically active metal particles, but may be extended longer if necessary. In addition, the size of the catalytically active metal particles can be adjusted by repeatedly performing thermal shock at specific time intervals ranging from 0.001 to 10 seconds.

At this time, the catalytically active metal supported on the catalyst support may have an average particle size of 0.1 nm to 50 nm, preferably 1 nm to 3 nm. If the average particle size of the catalytically active metal is less than 0.1 nm, it is difficult to expect an effective dehydrogenation reaction because the amount of catalytic alloy elements supported is significantly smaller than that of the catalyst support, and if the amount supported is smaller, a single element catalyst (single element catalyst) Because it is bound to the support in the form of a single element classified as an atom catalyst, its reactivity with LOHC organisms with relatively large molecular weight may be low. On the other hand, if the average particle size of the catalytically active metal exceeds 50 nm, the active surface of the catalyst becomes smaller compared to the amount of catalyst supported, which may reduce catalytic efficiency. As the particles become larger, they may be detached from the surface of the catalyst support during the dehydrogenation reaction. Problems may arise.

Looking at existing technologies for producing catalysts for dehydrogenation reactions, studies have been attempted to produce nanoparticles through a solution process. However, when produced through a solution process, the particles become larger in size or show uneven distribution during the long heat treatment process, and since the reduction levels of noble metal group elements and transition metal group elements are significantly different from each other, nano-sized alloys are formed without phase separation. Uniformly synthesizing particles was very limited. In particular, when multiple components are included, it is common to see phase separation due to the different bonding forces between different elements. It is difficult to call this a binary crystalline nanoparticle, and it has shown limitations in that it only shows the effect of the interface, not a new effect due to the alloy effect.

Accordingly, the catalyst for dehydrogenation reaction based on a liquid organic hydrogen carrier according to the present invention is manufactured by applying thermal shock through Joule heating to a catalyst support carrying a catalytically active metal, in a short time compared to conventional catalyst preparation methods. A simple method can provide uniform nanoparticle size and dispersion of the catalytically active metal, and the catalyst particle structure can be formed and controlled by controlling the current and time of Joule heating.

In addition, as shown in Figure 1, by applying thermal shock through Joule heating to a catalyst support carrying a catalytically active metal, alloys, intermetallic alloys, and amorphous alloys that are advantageous for the dehydrogenation reaction are produced. A new catalyst can be obtained in the form of (metallic glass).

Hereinafter, the method for producing a catalyst for dehydrogenation reaction based on a liquid organic hydrogen carrier according to the present invention will be described in detail.

The catalyst 100 for a liquid organic hydrogen carrier-based dehydrogenation reaction according to the present invention can be made by first applying a catalytically active metal 120 to a carbon-containing catalyst support 110.

The catalytically active metal can be applied on the catalyst support using a metal precursor 121 such as a salt or complex of the catalytically active metal. At this time, examples of the metal precursor of the catalytically active metal include water-soluble salts, specifically acetate, nitrate, sulfate, carbonate, hydroxide, halide, and hydrates thereof, and examples of the complex include acetylacetonate complex, phosphine complex, etc. It can be exemplified. In particular, nitrate or its hydrate can be used.

As an example, metal precursors of catalytically active metals may be contacted with the catalyst support in the form of a solution dissolved in water or a solvent. In this way, during the loading process, the catalyst support is in contact with the metal precursor solution for a predetermined period of time, and the loading temperature is carried out at room temperature. After the metal precursors are supported, usual follow-up procedures, such as filtration and drying steps to remove moisture or solvent, can be performed, and the drying temperature can be adjusted between 50°C and 120°C. This drying should be understood as exemplary.

At this time, the metal precursors may be mixed and brought into contact with the catalyst support, and the metal precursor of one of the catalytically active metals may be brought into contact with the catalyst support first, and then the metal precursors of the remaining metals may be mixed or brought into contact sequentially.

Thereafter, the catalyst support 110 on which the catalytically active metal 120 is applied is subjected to thermal shock through Joule heating to prepare a catalyst for the dehydrogenation reaction.

The step of applying thermal shock through Joule heating to the catalyst support on which the catalytically active metal is supported is applying a current corresponding to 0.1 A to 30 A under vacuum conditions or a reducing atmosphere injected with an inert gas to apply thermal shock. As a result, under a reducing atmosphere, non-metallic ligands present in an ionic state on the catalyst support are removed, and diffusion and reduction processes of catalytically active metal ions occur simultaneously, thereby inducing crystal nucleation at defect points on the surface of the catalyst support. At this time, when the temperature exceeds a sufficient temperature, various elements are melted and alloyed at high entropy, and when the current supply to the catalyst support is momentarily stopped and the heat source is lost, a quenching effect occurs and catalyst particles are formed. is strongly bound to the support in an alloyed state. When sufficient heat generated by the thermal shock is generated, light is emitted from the carbon-containing catalyst support. The lower the temperature, the darker red the light is, and the higher the temperature, the closer to white light is emitted.

The intensity of the thermal shock was proportional to the amount of power applied to the catalyst support per unit area, and it is desirable to apply appropriate voltage and current values depending on the resistance value of the catalyst support. By adjusting the amount of applied current, voltage value, etc., alloying of the catalytically active metal can be induced. The time to apply power is preferably adjusted within the range of 0.001 seconds to 10 seconds according to the target dispersion degree and particle size, but may be extended further if necessary. Additionally, alloying and particle size can be controlled by repeatedly applying thermal shock at specific time intervals ranging from 0.001 to 10 seconds.

The number of applications of the thermal shock may be repeated from 1 to 30 times in consideration of securing the crystallinity and catalytic activity of the catalytically active metal and process efficiency, but is not limited thereto.

The catalyst for the liquid organic hydrogen carrier-based dehydrogenation reaction according to the present invention prepared as described above is manufactured by alloying the previously used platinum-based catalyst with a metal that is relatively easy to obtain and inexpensive by thermal shock. A highly durable catalyst without desorption of active metals can be manufactured simply at low cost, and the particle structure of the catalyst can be formed and controlled so that catalytic activity and specific surface area per mass of catalyst metal are not reduced, thereby improving catalytic activity. there is.

In addition, the catalyst for dehydrogenation reaction based on a liquid organic hydrogen carrier according to the present invention is applied to a hydrogen emission system that generates and emits hydrogen for use in fuel cells and hydrogen combustion devices such as automobiles and various electronic products, using hot air or electric heaters. Unlike the external heating method used, heating through Joule heating not only allows the catalyst to be selectively heated, but also the heating intensity of the catalyst can be easily adjusted by adjusting the voltage and amount of current applied to the catalyst.

In addition, the present invention is a method for producing hydrogen by dehydrogenation of a liquid organic hydrogen carrier, characterized in that the dehydrogenation reaction is performed within the liquid organic hydrogen carrier by applying an electric current to the catalyst according to the present invention. A method for producing hydrogen by dehydrogenation is provided.

In another preferred embodiment of the present invention, the temperature of the surface of the catalyst support by applying the current may be set to 500°C to 2,500°C. If the temperature is less than 500°C, dehydrogenation may be incomplete because the ligands in the catalytically active metal precursor may not be completely removed or melted and cannot be synthesized, and if it exceeds 2,500°C, sintering of the catalytically active metal element may occur. ) effect can cause the particle size to become relatively large or damage the catalyst support, which can be a factor in reducing catalyst activity.

Hereinafter, the present invention will be described in more detail through experimental examples and examples. However, the following examples are for illustrative purposes only, and the scope of the present invention is not limited to these examples.

<Example 1>

0.189 g of the metal precursor hexachloroplatinic acid (H ₂ PtCl ₆ ·xH ₂ O) was dissolved in water and then impregnated into a carbon monolith, which was a catalyst support. Afterwards, calcination was performed at 350°C for 1 hour in an argon (Ar) atmosphere, and then reduced at 450°C for 1 hour in a hydrogen atmosphere to produce platinum carbon with 3 wt% of catalytically active metal (Pt) supported on the total weight. A monolith (Pt carbon monolith) was prepared.

<Example 2>

To synthesize 1:1 Pt and Cu alloy catalyst particles PtCu, 0.0102 g of Pt precursor [tetraamine platinum nitrate (H ₁₂ N ₆ O ₆ Pt)] and 0.0033 g of Cu precursor [copper acetate (CuCO ₂ CH ₃ )] g was mixed with 0.3 g of DI water to obtain a precursor solution, and 0.3 g of the aqueous solution in which the obtained precursor was dissolved was placed on a 1 cm × 4.8 cm activated carbon fiber (ACF) sheet catalyst support using a micropitpet. It was applied evenly over the entire area. The activated carbon fiber support coated with the above mixture was dried in an oven at 110° C. for 1 hour, then placed in a thermal shock chamber capable of applying voltage to both ends, and then Ar was flowed to maintain a reducing atmosphere. Afterwards, thermal shock was performed for 0.5 seconds at 160 V and 12 A to prepare a dehydrogenation catalyst (PtCu/ACF) containing 13.5% by weight of the catalytically active metal PtCu mixture based on the total weight of the catalyst.

<Example 3>

To synthesize PtPd, a 1:1 alloy catalyst particle of Pt and Pd, 0.0102 g of Pt precursor [tetraamine platinum nitrate (H ₁₂ N ₆ O ₆ Pt)] and 0.0102 g of Pd precursor [palladium nitrate hydrate (N ₂ O ₆ Pd) )] 0.0155 g was mixed with 0.3 g of DI water to obtain a precursor solution, and 0.3 g of the aqueous solution in which the obtained precursor was dissolved was spread on an activated carbon fiber (ACF) sheet catalyst support with a size of 1 cm × 4.8 cm. It was evenly applied to the entire area using a micropitpet. The activated carbon fiber support to which the mixture was applied was dried in an oven at 110°C for 1 hour, then placed in a thermal shock chamber capable of applying voltage to both ends, and then Ar was passed through it to maintain a reducing atmosphere. Afterwards, thermal shock was performed for 0.5 seconds at 160 V and 12 A to prepare a dehydrogenation catalyst (PtCu/ACF) containing 25.8% by weight of the catalytically active metal PtPd mixture based on the total weight of the catalyst.

<Example 4>

To synthesize Pt, Pd, Cu, Ci and Co alloy catalyst particles PtPdCuNiCi of 1:1:1:1, 0.0041 g of Pt precursor [tetraamine platinum nitrate (H ₁₂ N ₆ O ₆ Pt)], 0.0041 g of Pd precursor [ Palladium nitrate hydrate (N ₂ O ₆ Pd)] 0.0062 g, Cu precursor [copper acetate (CuCO ₂ CH ₃ )] 0.0013 g, Ni precursor [nickel nitrate hexahydrate (Ni(NO ₃ ) ₂ .6H ₂ O) ] 0.0032 g and 0.0032 g of Co precursor [cobalt nitrate hexahydrate (Co(NO ₃ ) ₂ ·6H ₂ O)] were mixed with 0.3 g of DI water to obtain a precursor solution, and 0.3 g of an aqueous solution in which the obtained precursor was dissolved was mixed. was evenly applied to the entire surface of an activated carbon fiber (ACF) sheet catalyst support measuring 1 cm × 4.8 cm using a micropitpet. The activated carbon fiber catalyst support coated with the above mixture was dried in an oven at 110° C. for 1 hour, placed in a thermal shock chamber capable of applying voltage to both ends, and then Ar was flowed to maintain a reducing atmosphere. Afterwards, thermal shock was performed for 0.5 seconds at 160 V and 12 A to prepare a dehydrogenation catalyst (PtPdCuNiCo/ACF) containing 18% by weight of the catalytically active metal PtPdCuNiCo mixture based on the total weight of the catalyst.

<Comparative Example 1>

0.189 g of hexachloroplatinic acid (H ₂ PtCl ₆ ·xH ₂ O) was dissolved in 1.62 ml of DI water, and then 3 g of gamma-alumina (gamma-Al ₂ O ₃ ) powder was impregnated with the aqueous solution (incipient wetness impregnation). . Afterwards, it was treated in a sonicator for 30 minutes and dried at 110°C for 12 hours. Afterwards, it was calcined at 350°C for 1 hour in an air atmosphere, and then reduced at 450°C for 1 hour in a hydrogen atmosphere to produce a dehydrogenation catalyst (Pt/Al ₂ O ₃ ) containing 3 wt% of Pt based on the total weight of the catalyst. was manufactured.

<Comparative Example 2>

0.0102 g of Pt precursor [tetraamine platinum nitrate (H ₁₂ N ₆ O ₆ Pt)] was mixed with 0.3 g of DI water to obtain a precursor solution, and 0.3 g of the aqueous solution in which the obtained precursor was dissolved was mixed in a 1 cm × 4.8 cm It was evenly applied to the entire surface of an activated carbon fiber (ACF) sheet catalyst support using a micropitpet. The activated carbon fiber catalyst support to which the above mixture was applied was dried in an oven at 110°C for 1 hour, then placed in a thermal shock chamber capable of applying voltage to both ends, and then Ar was flowed to maintain a reducing atmosphere. . Afterwards, the process was performed at 160 V and 12 A for 0.5 seconds to prepare a dehydrogenation catalyst (Pt/ACF) containing 10.2% by weight of the catalytically active metal Pt mixture based on the total weight of the catalyst.

<Experimental Example 1>

Two metal wires were connected to the catalyst platinum carbon monolith (Pt carbon monolith) prepared in Example 1 using carbon paste. This was charged into a glass cylindrical reactor, and then 4 g (13.79 mmol) of H18-dibenzyltoluene (perhydro dibenzyltoluene) as a reactant was injected. After applying direct current to the metal wire connected to the catalyst through the power supply, the temperature of the catalyst module was controlled to 300°C using a control module and heated for 2 hours to perform a dehydrogenation reaction. After the reaction, the amount of hydrogen released according to the reaction time was measured and shown in Figure 3.

Meanwhile, 350 mg of the Pt/Al ₂ O ₃ powder catalyst prepared in Comparative Example 1 was introduced into a glass cylindrical reactor. Afterwards, 4 g (13.79 mmol) of H18-dibenzyltoluene (perhydro dibenzyltoluene), a H ₂ -rich LOHC reactant, was injected, and a heating mantle suitable for a cylindrical reactor was installed and heated to 300°C. At this time, the dehydrogenation conversion rate and dehydrogenation reaction activity according to temperature and time were measured, respectively, and are shown in Figure 3.

As shown in Figure 3, it was confirmed that the catalyst of Example 1 could generate a greater amount of hydrogen during the same time with the same amount of catalyst compared to Comparative Example 1, which is a general dehydrogenation catalyst. This results in the fact that the system that activates the catalyst by selectively heating it by Joule heating inside the liquid organic hydrogen carrier (Example 1) is more effective than the case where heat is supplied from the outside in the endothermic dehydrogenation reaction (Comparative Example 1). represents.

<Experimental Example 2>

The catalysts prepared in Examples 2 to 4 and Comparative Example 2 were respectively charged into a glass cylindrical reactor, and then 4 g (13.79 mmol) of H18-dibenzyltoluene (perhydro dibenzyltoluene) as a reactant was injected. A heating mantle suitable for the cylindrical reactor was installed and heated at 300°C for 8 hours. At this time, the dehydrogenation conversion rate and dehydrogenation reaction activity according to temperature and time were measured, respectively, and are shown in Figure 4.

As shown in Figure 4, the catalyst group in Examples 2 to 4, in which Pt is alloyed with more than one type, shows a higher dehydrogenation reaction under the same reaction conditions than the Pt/ACF consisting of only a single Pt element, which is Comparative Example 2, and the alloy catalyst It was confirmed that it was effective in releasing hydrogen. The amount of Pt used in manufacturing in Examples 2 to 4 was the same as the amount of Pt used in manufacturing in Comparative Example 2, but it was found that when Pt was alloyed with different types of elements, the dehydrogenation reaction was improved, and through this, the value It was confirmed that there is a groundbreaking inventive step that can reduce the amount of expensive precious metal catalyst and increase dehydrogenation activity.

The present invention has been described above with reference to the accompanying drawings and examples, but these are merely illustrative, and those skilled in the art will recognize that various modifications and other equivalent embodiments are possible therefrom. You will understand. Therefore, the scope of technical protection of the present invention should be determined by the claims below.

100: Catalyst for dehydrogenation reaction based on liquid organic hydrogen carrier
110: catalyst support
120: Catalytically active metal

Claims (12)

A catalyst for the dehydrogenation reaction of a liquid organic hydrogen carrier, which is dehydrogenated in the liquid organic hydrogen carrier using Joule heating,
A support made of a material that can generate heat by string heating; and
It includes a catalytically active metal supported on the support,
The catalytically active metal includes any one of copper (Cu) and palladium (Pd), and platinum (Pt), and is alloyed and supported on a catalyst support by thermal shock. Catalyst for dehydrogenation reaction of hydrogen carriers.
delete delete According to paragraph 1,
A catalyst for the dehydrogenation reaction of a liquid organic hydrogen carrier by Joule heating, characterized in that the catalytically active metal is contained in an amount of 0.1% by weight to 50% by weight based on the total weight of the catalyst.
According to paragraph 1,
A catalyst for the dehydrogenation reaction of a liquid organic hydrogen carrier by Joule heating, characterized in that the support is at least one selected from the group consisting of activated carbon, carbon fiber, carbon tube, fullerene, carbon black, and carbide series.
According to paragraph 1,
The support is characterized in that it has a shape selected from the group consisting of corrugate, plate, monolith, foam, fiber, granule, and mesh. Catalyst for dehydrogenation of liquid organic hydrogen carriers by Joule heating.
In the method for producing a catalyst for a liquid organic hydrogen carrier dehydrogenation reaction that dehydrogenates a liquid organic hydrogen carrier using Joule heating,
The catalyst for the liquid organic hydrogen carrier dehydrogenation reaction is supported by alloying a catalytically active metal including either copper (Cu), palladium (Pd), or platinum (Pt) on a support of a material that generates heat by Joule heating. A method for producing a catalyst for the dehydrogenation reaction of a liquid organic hydrogen carrier, comprising the step of:
In clause 7,
The catalytically active metal is supported
(a) applying a catalytically active metal to a carbon-containing catalyst support; and
(b) applying a thermal shock to the catalyst support coated with the catalytically active metal; A method for producing a catalyst for a dehydrogenation reaction based on a liquid organic hydrogen carrier, comprising:
According to clause 8,
The thermal shock in step (b) is performed by applying a current of 0.1 A to 30 A and heating to a temperature of 500 ℃ to 2,500 ℃. A method for producing a catalyst for dehydrogenation reaction based on a liquid organic hydrogen carrier.
According to clause 8,
A method for producing a catalyst for dehydrogenation reaction based on a liquid organic hydrogen carrier, characterized in that the thermal shock in step (b) is performed 1 to 30 times.
In a method for producing hydrogen by dehydrogenation of a liquid organic hydrogen carrier,
A method for producing hydrogen by dehydrogenation of a liquid organic hydrogen carrier, characterized in that the dehydrogenation reaction is performed by applying an electric current to the catalyst of any one of claims 1 to 6.
According to clause 11,
A method of producing hydrogen by dehydrogenation of a liquid organic hydrogen carrier, characterized in that the temperature of the surface of the support by applying the current is 500 ℃ to 2,500 ℃.