KR20210065592A - Catalysts for ionic liquid decomposition and manufacturing method thereof and decomposition method of ionic liquid - Google Patents

Abstract

The present invention relates to a catalyst for decomposition of an ionic liquid, which comprises: a porous ceramic structure; and a metal coating layer formed on the porous ceramic structure and comprising a platinum-based metal and copper, a manufacturing method thereof and a decomposition method of an ionic liquid using the same. The catalyst for decomposition of the ionic liquid has a low ionic liquid decomposition initiation temperature and stable heat resistance even at high temperatures.

Description

Catalyst for decomposition of ionic liquid, method for preparing the same, and method for decomposing ionic liquid using the same {CATALYSTS FOR IONIC LIQUID DECOMPOSITION AND MANUFACTURING METHOD THEREOF AND DECOMPOSITION METHOD OF IONIC LIQUID}

The present invention relates to a catalyst for decomposing an ionic liquid, a method for preparing the same, and a method for decomposing an ionic liquid using the same.

_{Hydrazine (N 2} H ₄ ) propellant used in thrusters for attitude control of artificial satellites and thrusters of long-range rocket propulsion engines is a highly toxic substance, and research on alternative substances is being actively conducted worldwide.

Therefore, recently overseas, hydroxylammonium nitrate (NH ₃ OHNO ₃ ), hydrazinium _{nitroformate (N 2} H ₅ C(NO ₂ ) ₃ ) and ammonium dinitroamide (NH ₄ N (NO ₂ ) ₂ ) based on eco-friendly, low-toxic liquid single propellant is being actively developed. Among them, the hydroxyl ammonium nitrate-based propellant is an ionic liquid in an aqueous solution state, does not generate carcinogens or mutagenic substances, and the combustion gas is also close to non-toxic and has environmental-friendly characteristics.

Moreover, the hydroxylammonium nitrate-based propellant has an excellent driving force when applied as a propellant because it has a sufficient amount of oxygen. In addition, since it has a low freezing point and a high density, the physical properties are also very good. In addition, since it has a high solubility in water even at a temperature below the boiling point of water, it has the advantage of lowering the final combustion temperature or heating temperature at the bottom of the thruster by using water as a solvent.

However, hydroxylammonium nitrate-based propellants have difficulty in ignition due to their high moisture content. Accordingly, the propellant must be decomposed by heating to at least 200° C., at this time, the decomposition uses a catalyst, and the lower the heating temperature for initiation, the better the efficiency. In addition, the hydroxyl ammonium nitrate-based propellant should not be vulnerable to such an environment because the temperature at the bottom of the thruster and the temperature of the catalyst bed rise to a high temperature during decomposition through ignition.

Accordingly, in order to use a hydroxyl ammonium nitrate-based propellant, it is essential to use a catalyst that has excellent low-temperature decomposition activity and can withstand high temperatures.

Conventionally, a catalyst in which an oxide of a metal selected from iridium, platinum, rhodium, and palladium, etc. is supported on a support such as alumina as a catalyst material most often used to decompose hydroxylammonium nitrate-based propellants was used.

Such a catalyst has the disadvantage that it is very expensive, and the decomposition efficiency of the propellant is not good.

Therefore, there is a need for the development of a catalyst that is economical and has excellent decomposition activity of ionic liquids and at the same time has excellent heat resistance at high temperatures.

R. Amrousse et al., Combustion and Flame 162 (2015) 2686-2692

It is an object of the present invention to provide a catalyst for decomposition of ionic liquids having excellent low-temperature activity with respect to decomposition of ionic liquids. Specifically, to provide a catalyst for decomposition of an ionic liquid having a low ionic liquid decomposition initiation temperature and stable heat resistance even at high temperatures.

Another object of the present invention is to provide a method for preparing a catalyst for decomposing an ionic liquid that can achieve the above object. Specifically, it is to prepare a catalyst for decomposition of an ionic liquid that does not cause damage or deformation after calcination while also securing price competitiveness.

Another object of the present invention is to provide a method for decomposing an ionic liquid with excellent efficiency using the above-described catalyst for decomposing an ionic liquid.

The catalyst for decomposition of an ionic liquid according to the present invention includes a porous ceramic structure; and a metal coating layer formed on the porous ceramic structure and including a platinum-based metal and copper.

The platinum-based metal according to an embodiment of the present invention may be platinum or iridium.

The porous ceramic structure according to an embodiment of the present invention may be a cordierite monolith.

The supported amount of the platinum-based metal according to an embodiment of the present invention may be 0.1 to 30% by weight, based on the total weight of the catalyst for decomposition of ionic liquids, and the supported amount of copper is based on the total weight of the catalyst for decomposition of ionic liquids , may be 5 to 60% by weight.

Another embodiment according to the present invention is a method for decomposing an ionic liquid by inducing a decomposition reaction by contacting a catalyst for decomposition of an ionic liquid including a metal coating layer including a platinum-based metal and copper on a porous ceramic structure with the ionic liquid is about

The ionic liquid according to an embodiment of the present invention may be a single propellant.

Another embodiment according to the present invention comprises the steps of: a) immersing a porous ceramic structure in a precursor solution containing a platinum-based metal precursor and a copper precursor to form a precursor coating layer; b) forming a metal coating layer by firing the porous ceramic structure on which the precursor coating layer is formed; It relates to a method for producing a catalyst for decomposition of an ionic liquid comprising a.

The firing according to an embodiment of the present invention may be performed at 1,000°C or higher.

The platinum-based metal precursor according to an embodiment of the present invention may be a platinum precursor or an iridium precursor.

The porous ceramic structure according to an embodiment of the present invention may further perform a pretreatment step before step a).

The catalyst for decomposition of an ionic liquid according to the present invention has an advantage in that it has a low decomposition temperature and is excellent in low-temperature decomposition activity and at the same time is excellent in decomposition activity of a high concentration ionic liquid.

In addition, the catalyst for decomposing an ionic liquid according to the present invention has advantages in that it has price competitiveness and heat resistance that can withstand a high temperature environment.

In addition, there is an advantage that the ionic liquid can be decomposed with high efficiency using the catalyst for decomposing the ionic liquid according to the present invention.

1 is an observation of the form of a catalyst for decomposition of an ionic liquid of Example 1 according to an embodiment of the present invention.
Figure 2 is an observation of the form of the catalyst for decomposition of the ionic liquid of Comparative Example 4 according to the Comparative Example of the present invention.

Advantages and features of embodiments of the present invention, and methods of achieving them, will become apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms, and only these embodiments allow the disclosure of the present invention to be complete, and common knowledge in the art to which the present invention pertains 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. Like reference numerals refer to like elements throughout.

In describing the embodiments of the present invention, if it is determined that a detailed description of a well-known function or configuration may unnecessarily obscure the gist of the present invention, the detailed description thereof will be omitted. In addition, the terms to be described later are terms defined in consideration of functions in an embodiment of the present invention, which may vary according to intentions or customs of users and operators. Therefore, the definition should be made based on the content throughout this specification.

As used herein, the term “monolith” refers to a structure in which hollow rod-shaped spaces are connected in a ceramic honeycomb (honeycomb) structure.

As used herein, "cordierite" has _{a chemical formula of 2M g} O·2Al ₂ O ₃ ·5SiO ₂ , and is derived from a ternary system between magnesia (MgO), alumina (Al ₂ O ₃ ) and silica (SiO _{2 ).} is a compound.

To achieve the above object, this invention relates to a catalyst for decomposing an ionic liquid, a method for preparing the same, and a method for decomposing an ionic liquid using the same.

If we explain this invention in detail, it is as follows.

The catalyst for decomposition of an ionic liquid according to the present invention includes a porous ceramic structure; and a metal coating layer formed on the porous ceramic structure and including a platinum-based metal and copper.

The decomposition efficiency of the ionic liquid may be further increased when the decomposition reaction is performed at a low temperature. In particular, ionic liquids are used as propellants in the aerospace field such as rockets. In this case, the propellants reduce the decomposition initiation temperature to lower the heating temperature of the propellant to further improve the use efficiency, and to reduce the temperature increase due to heating. It is important to have tolerable heat resistance.

The catalyst for decomposition of an ionic liquid according to the present invention has a low decomposition initiation temperature, so it has excellent low-temperature decomposition activity, and has heat resistance that can stably withstand high temperatures, thereby being excellent as a propellant.

The catalyst for decomposition of an ionic liquid according to the present invention is a porous ceramic structure; and a metal coating layer formed on the porous ceramic structure and including a platinum-based metal and copper. If it is not a porous ceramic structure or the metal coating layer is also composed of a metal other than platinum-based metal and copper or an oxide thereof, low-temperature decomposition activity and heat resistance cannot be secured at the same time or the improvement is insignificant.

According to an embodiment of the present invention, the porous ceramic structure is a ceramic structure having porosity, and as a specific example, it may be a structure selected from a cordierite-based ceramic structure, a ceramic structure manufactured using ceramic paper, a ceramic foam, and the like. can Preferably, in order to maximize the above-described object of the present invention, the porous ceramic structure may be a cordierite monolith. When the metal coating layer according to the present invention is formed on the porous ceramic structure, the decomposition initiation temperature can be significantly reduced to further improve the decomposition activity at low temperature, and excellent heat resistance at high temperature can be secured.

According to an embodiment of the present invention, the metal coating layer may include a platinum-based metal and copper. Specifically, a platinum-based metal selected from platinum or iridium; and copper; By including both the platinum-based metal and copper, it can be used in a high-temperature environment, and decomposition efficiency can be maximized. Moreover, the catalyst for decomposition of an ionic liquid prepared therefrom has excellent decomposition activity at a low decomposition initiation temperature.

In the past, noble metal catalysts using only platinum-based metals were used, but the production cost was very high, so the productivity and price competitiveness were remarkably low, and the low-temperature decomposition activity was not good because the reduction in the decomposition initiation temperature was insignificant. In addition, when only copper is used, damage and deformation occur in a high-temperature environment, so that it is not suitable as a catalyst for decomposition of ionic liquids.

On the other hand, the catalyst for decomposition of an ionic liquid according to the present invention includes a platinum-based metal; and copper; by simultaneously applying, not only securing productivity and price competitiveness, but also having excellent low-temperature decomposition activity due to the effect of reducing the unexpected decomposition initiation temperature, and at the same time having excellent heat resistance, thereby completing the present invention.

In addition, when a coating layer is formed of, for example, copper oxide (CuO), etc., such as a platinum-based metal and an oxide of copper, a reaction other than the decomposition of the ionic liquid is induced in a high-temperature environment, so that the ionic liquid decomposition selectivity and Since the efficiency is reduced, the catalyst activity is not good, and it is not suitable for use in a high temperature environment, so it is difficult to achieve the above-described effect according to the present invention.

According to an embodiment of the present invention, the metal coating layer may include 0.1 to 40% by weight of a platinum-based metal and 60 to 99.9% by weight of copper based on the total weight. Preferably, it may contain 1 to 35% by weight of a platinum-based metal and 65 to 99% by weight of copper. When the content is as described above, low-temperature decomposition activity and heat resistance can be further improved.

More specifically, when the platinum-based metal is iridium, 0.1 to 40% by weight of iridium and 60 to 99.9% by weight of copper based on the total weight of the metal coating layer may be included, preferably 1 to 20% by weight of iridium and 80% by weight of copper to 99% by weight. More preferably, 1 to 10% by weight of iridium and 90 to 99% by weight of copper may be included. In the case of iridium, even if a small amount is coated, the decomposition initiation temperature can be significantly reduced, and heat resistance can be secured.

In addition, when the platinum-based metal is platinum, it may include 0.1 to 40% by weight of platinum and 60 to 99.9% by weight of copper, preferably 5 to 40% by weight of platinum and 60 to 95% by weight of copper, based on the total weight of the metal coating layer. % by weight. More preferably, 10 to 35% by weight of platinum and 65 to 90% by weight of copper may be included. In the case of platinum, it is possible to secure a large amount of support with excellent adhesion with a small amount of platinum precursor, thereby securing a catalyst with excellent low-temperature decomposition activity efficiency, and at the same time, deformation and damage do not occur even in a high-temperature environment.

According to an embodiment of the present invention, the supported amount of the platinum-based metal may be 0.1 to 30% by weight, preferably 1 to 20% by weight, more preferably based on the total weight of the catalyst for decomposition of the ionic liquid. Preferably, it may be 1 to 15% by weight.

In addition, when the platinum-based metal is iridium, the supported amount may be 0.1 to 30% by weight, preferably 1 to 10% by weight, more preferably 1, based on the total weight of the catalyst for decomposition of the ionic liquid. to 5% by weight.

In addition, when the platinum-based metal is platinum, the supported amount may be 0.1 to 30% by weight, preferably 1 to 20% by weight, more preferably 5 based on the total weight of the catalyst for decomposing the ionic liquid. It may be 15% by weight.

When the metal coating layer is formed with the above-mentioned loading amount, it is possible to secure high heat resistance and at the same time significantly reduce the decomposition heating temperature of the ionic liquid with a remarkably low decomposition initiation temperature, thereby further improving productivity and efficiency.

According to an embodiment of the present invention, the supported amount of copper may be 5 to 60% by weight based on the total weight of the catalyst for decomposition of the ionic liquid. Preferably it may be 10 to 50% by weight, more preferably 25 to 50% by weight. When the metal coating layer is formed in the amount supported, low-temperature decomposition activity and heat resistance can be significantly improved. Moreover, when the platinum-based metal loading amount is simultaneously satisfied, the above-described effect can be maximized.

According to an embodiment of the present invention, the catalyst for decomposition of the ionic liquid may have a decomposition initiation temperature of 70° C. or less. Specifically, it may be 10 to 60 °C, preferably 10 to 55 °C, and more preferably 10 to 50 °C. By having a low decomposition initiation temperature as described above, it is possible to significantly reduce the heating temperature for catalyst decomposition, thereby ensuring excellent productivity. Moreover, it has excellent heat resistance even at high temperatures, so that excellent activity can be expressed in a high temperature environment without reducing efficiency.

According to an embodiment of the present invention, the specific surface area of the catalyst for decomposition of the ionic liquid was measured by the BET (Brunauer-Emmett-Teller) method through nitrogen adsorption and desorption at a liquid nitrogen temperature (-196° C.), and the specific surface area may be 0.1 to 0.8 m ² /g, preferably 0.1 to 0.5 m ² /g, and more preferably 0.1 to 0.25 m ² /g.

According to an embodiment of the present invention, the pore size of the catalyst for decomposition of the ionic liquid was measured by a Porosimeter (Pore 　 master, Quantachrome Co.), and the pore size may be 1 to 100 nm, preferably 1 to 50 nm may be, and more preferably 1 to 10 nm.

When it has the specific surface area and pore size as described above, it may have excellent low-temperature decomposition activity.

Another embodiment according to the present invention is a method for decomposing an ionic liquid by inducing a decomposition reaction by contacting a catalyst for decomposition of an ionic liquid including a metal coating layer including a platinum-based metal and copper on a porous ceramic structure with the ionic liquid is about

In the catalyst for decomposing an ionic liquid according to the present invention, the types and contents of the porous ceramic structure and the metal coating layer described above are omitted.

By inducing a decomposition reaction by contacting the catalyst for decomposition of an ionic liquid according to the present invention to the ionic liquid, decomposition initiation occurs at a remarkably low temperature, so that decomposition activity can be smoothly performed at a low temperature. In addition, damage and deformation do not occur even in a high-temperature environment caused by a temperature increase caused by heating for inducing a reaction, so that a reduction in decomposition efficiency does not occur, and an excellent decomposition effect of an ionic liquid can be expressed.

According to an embodiment of the present invention, the ionic liquid may be a single propellant used in aerospace fields such as rockets. In a specific example, the single propellant is hydroxylammonium nitrate (NH ₃ OHNO ₃ ), hydrazinium _{nitroformate (N 2} H ₅ C(NO ₂ ) ₃ ) and ammonium dinitroamide (NH ₄ N(NO _{2 )} ) may be any one or a mixture of two or more selected from _{2) and the like.} Preferably, it may be hydroxylammonium nitrate (NH ₃ OHNO ₃ ) capable of maximizing effect expression.

Another embodiment according to the present invention comprises the steps of: a) immersing a porous ceramic structure in a precursor solution containing a platinum-based metal precursor and a copper precursor to form a precursor coating layer; b) forming a metal coating layer by sintering the porous ceramic structure on which the precursor coating layer is formed; relates to a method for producing a catalyst for decomposition of an ionic liquid comprising a.

Step a) according to the present invention is a step of forming a precursor coating layer by immersing the porous ceramic structure in a precursor solution containing a platinum-based metal precursor and a copper precursor. A precursor coating layer may be formed on the porous ceramic structure through step a).

According to an embodiment of the present invention, the precursor solution may include a platinum-based metal precursor, a copper precursor, and a solvent. Preferably, the platinum-based metal precursor may include a platinum precursor or an iridium precursor. The solvent is not particularly limited as long as it can disperse or dissolve the platinum-based metal precursor. For example, it may be the same as the solvent of the ionic liquid for decomposition, specifically water.

Specifically, according to an example, the platinum-based metal precursor is, for example, when the platinum-based metal precursor is platinum, chloroplatinic acid, platinum oxide, platinum bromide, platinum acetylacetonate, platinum dioxide, platinum acetic acid, platinum nitrate, and It may be any one or a mixture of two or more selected from hydrates thereof, but is not limited thereto. In addition, when the platinum-based metal precursor is iridium, it may be any one or a mixture of two or more selected from iridium oxide, iridium nitrate, iridium acetylacetonate, iridium acetic acid, iridic acid chloride, and hydrates thereof, but is limited thereto no.

Specifically, according to an example, the copper precursor is, for example, copper sulfate, copper nitrate, copper chloride, copper bromide, copper carbonate, copper acetylacetonate, copper acetic acid, copper hydroxide, copper oxide, copper dioxide, hydrates thereof, etc. It may be any one or a mixture of two or more selected, but is not limited thereto.

Step b) according to the present invention is a step of forming a metal coating layer by firing the porous ceramic structure on which the precursor coating layer is formed. By performing step b), the precursor coating layer forms a metal coating layer as an active metal, thereby promoting the ionic liquid decomposition reaction, thereby further improving the decomposition efficiency.

According to an embodiment of the present invention, the sintering may be performed at 1,000° C. or higher. Specifically, the sintering may be performed at 1,000 to 1,500 °C, preferably at 1,000 to 1,350 °C, more preferably at 1,100 to 1,300 °C. By calcining at the above temperature, a metal coating layer having high purity of pure metal can be formed, and a catalyst having excellent decomposition selectivity for ionic liquids and significantly improved low-temperature decomposition activity and heat resistance can be provided.

According to an embodiment of the present invention, the sintering may be performed for 1 to 10 hours, but is not limited thereto.

According to an embodiment of the present invention, the step of drying after forming the metal precursor coating layer may be further performed. For example, the drying may be performed at a temperature of 80 to 150° C. for 1 to 10 hours, but is not limited thereto.

According to an embodiment of the present invention, the porous ceramic structure may further perform a pretreatment step before step a). By removing impurities and organic matter through the pretreatment, the adhesion of the metal coating layer can be further improved, and better low-temperature activity and heat resistance can be secured.

Specifically, the pretreatment is not particularly limited in the type of the washing solution, but for example, after each washing using an acid, base, organic solvent or surfactant aqueous solution, drying and calcining at a temperature of 500 to 1,000 ° C. it could be Any one may be used for the washing, and when two or more are used, each washing step may be independently performed in two or more steps. Thereafter, a washing step may be further performed with distilled water or an organic solvent, but the present invention is not limited thereto.

According to an embodiment of the present invention, the porous ceramic structure may use a surface coated with an active metal in order to realize a more improved effect, but is not limited thereto.

The catalyst for decomposition of an ionic liquid according to the present invention has a significantly low decomposition initiation temperature, and thus has excellent low-temperature decomposition activity, and has heat resistance that exhibits effects without deformation and efficiency reduction even in a high-temperature environment. It is excellent as a catalyst for decomposition of propellants.

Hereinafter, the present invention will be specifically described by way of Examples and Comparative Examples. The examples below are only for helping understanding of the present invention, and the scope of the present invention is not limited by the examples below.

[Method of measuring physical properties]

1) Decomposition onset temperature

Add 0.3 g of catalyst for decomposition of ionic liquid into the reactor made of SUS 316. Thereafter, 100 μl of a 70 wt% aqueous solution of hydroxylammonium nitrate is wetted using a micropipette. At the same time, the upper part of the reactor was combined, and the temperature of the internal catalyst layer, the temperature and pressure of the gas phase were measured 100 times per second. At this time, the temperature was increased from room temperature to 200°C at a temperature increase rate of 10°C/min. The point where the catalyst temperature starts to rise due to strong exotherm during decomposition of the 70 wt% hydroxylammonium nitrate aqueous solution was described as the decomposition initiation temperature.

2) Measurement of loading amount

After finely pulverizing the metal-supported catalyst for decomposition of ionic liquids on a cordierite monolith support to make a powder, X-ray fluorescence analysis (SPEX SamplePrep 3635 X-Press, SPEX Sample Prep Group, USA) was performed to determine the amount of metal supported Confirmed.

[Example 1]

A cylindrical cordierite monolith having a diameter of 1 cm and a height of 1 cm was immersed in 500 ml of a molar concentration of 1 M aqueous sodium hydroxide solution, washed through a sonicate for 15 minutes, and then dried in an oven at 110 ° C. After drying, the cordierite monolith was immersed in 500 ml of an aqueous solution of 0.5 M hydrochloric acid with a molar concentration, and then washed through a sonicate for 15 minutes, and then dried in an oven at 110°C. Thereafter, the cordierite monolith was immersed in 500 ml of distilled water, washed through a sonicate for 15 minutes, and then dried in an oven at 110°C. After that, it was calcined at 900°C for 12 hours. After sintering, the cordierite monolith was immersed in 500 ml of toluene, washed through a sonicate for 15 minutes, and then dried in an oven at 110°C. This was repeated twice. Finally, the cordierite monolith was immersed in a molar concentration of 0.1 M aqueous acetyltrimethylammonium bromide solution, washed for 5 hours, and dried in an oven at 110° C. for pretreatment.

Copper nitrate (Cu(NO ₃ ) ₂ ·H ₂ O) 0.55 g and chloroplatinic acid (H ₂ PtCl ₆ ·6H ₂ O) 0.080 g were added to 500 ml of distilled water and dissolved to prepare a precursor solution. After that, 5 pretreated cordierite monoliths (0.3 g, 1 cm in diameter, 1 cm in height cylindrical, specific surface area 0.83 m ² /g, pore size 124.2 nm) were immersed in the precursor solution, and then 70 under reduced pressure. It was heated at ℃ for 6 hours. After heating, in order to evaporate distilled water in the precursor solution, it was dried at 100° C. for 4 hours. The drying process was repeated twice. Thereafter, the dried cordierite monolith was calcined at 1,200° C. for 4 hours to prepare a Pt-Cu catalyst in which a platinum-copper metal coating layer was formed on the cordierite monolith. It was confirmed that the cordierite monolith form of the prepared catalyst was maintained without damage and deformation, as shown in FIG. 1 .

[Example 2]

Example 1 a precursor solution in a copper nitrate _{(Cu (NO 3) 2 ·} H 2 O) 0.60g and chloroplatinic acid _{(H 2 PtCl 6 · 6H 2} O) dissolved in distilled water, 0.040g 500㎖ by Pt-Cu catalyst The same procedure was performed except that

[Example 3]

Example 1 a precursor solution in a copper nitrate _{(Cu (NO 3) 2 ·} H 2 O) 0.55g and chloroplatinic acid _{(H 2 PtCl 6 · 6H 2} O) dissolved in 0.10g of distilled water was 500㎖ Pt-Cu catalyst The same procedure was performed except that

[Example 4]

The precursor solution in Example 1 was dissolved in 500 ml of distilled water by dissolving _{0.72 g of a copper nitrate (Cu(NO 3} ) ₂ ·H ₂ O) precursor and 0.092 g of a chlorinated iridic acid (H ₂ Cl ₆ Ir·H _{2 O) precursor in 500 ml of distilled water.} The same procedure was carried out except that the Ir-Cu catalyst was prepared.

[Example 5]

In Example 1, the precursor solution was dissolved in 500 ml of distilled water by dissolving _{0.70 g of a copper nitrate (Cu(NO 3} ) ₂ ·H ₂ O) precursor and 0.10 g of a chlorinated iridic acid (H ₂ Cl ₆ Ir·H _{2 O) precursor in 500 ml of distilled water.} The same procedure was carried out except that the Ir-Cu catalyst was prepared.

[Example 6]

In Example 1, the precursor solution was dissolved in copper nitrate (Cu(NO ₃ ) ₂ ·H ₂ O) precursor 0.62 g and chlorinated iridic acid (H ₂ Cl ₆ Ir·H ₂ O) precursor 0.20 g in 500 ml of distilled water. The same procedure was carried out except that the Ir-Cu catalyst was prepared.

[Example 7]

The precursor solution in Example 1 was prepared by dissolving _{0.75 g of a copper nitrate (Cu(NO 3} ) ₂ ·H ₂ O) precursor and 0.08 g of a chlorinated iridic acid (H ₂ Cl ₆ Ir·H ₂ O) precursor in 500 ml of distilled water. The same procedure was carried out except that the Ir-Cu catalyst was prepared.

[Comparative Example 1]

The same procedure was performed except that in Example 1, only the pre-treated cordierite monolith was used without being immersed in the precursor solution.

[Comparative Example 2]

The same procedure was performed except that in Example 1, a nickel foam, not a cordierite monolith, was used.

[Comparative Example 3]

The precursor solution in Example 1 was carried out in the same manner as in Example 1, except that an Ir catalyst was prepared by dissolving 1.02 g of an iridic _{acid chloride (H 2} Cl ₆ Ir·H _{2 O) precursor in 500 ml of distilled water.}

[Comparative Example 4]

In Example 1, the precursor solution was prepared in the same manner except that a Pt catalyst was prepared by dissolving 0.78 g of a _{chloroplatinic acid (H 2} PtCl ₆ .6H _{2 O) precursor in 500 ml of distilled water.}

[Comparative Example 5]

In Example 1, the copper nitrate (Cu(NO ₃ ) ₂ ·H ₂ O) precursor was dissolved in 0.81 g of distilled water in 500 ml of distilled water to prepare a Cu catalyst in the same manner as in Example 1. At this time, it was confirmed that the shape of the cordierite monolith was deformed and collapsed as shown in FIG. 2 , and when the decomposition initiation temperature of the aqueous hydroxylammonium nitrate solution was measured, no decomposition reaction occurred.

Table 1 shows the results of the decomposition initiation temperature and the XRF component analysis of the ionic liquid propellant measured using the catalyst for decomposition of the ionic liquid according to Examples 1 to 7 and Comparative Examples 1 to 5 of the present invention.

Metal loading (wt%) porous ceramic
structure type decomposition
onset temperature
(℃) Copper iridium platinum Example 1 37.9 - 12.6 cordierite
monolith 53.8 Example 2 35.2 - 15.2 cordierite
monolith 57.2 Example 3 38.1 - 9.1 cordierite
monolith 56.3 Example 4 43.4 0.4 - cordierite
monolith 55.5 Example 5 33.4 2.4 - cordierite
monolith 49.1 Example 6 43.4 4.9 - cordierite
monolith 51.1 Example 7 24.5 0.2 - cordierite
monolith 56.9 Comparative Example 1 - - - cordierite
monolith 76.0 Comparative Example 2 33.1 - 7.3 Nickel Foam 61.0 Comparative Example 3 - 5.1 - cordierite
monolith 72.4 Comparative Example 4 - - 15.8 cordierite
monolith 72.9 Comparative Example 5 27.8 - - cordierite
monolith -

As shown in Table 1, when hydroxylammonium nitrate, which is an ionic liquid, was decomposed using the catalyst for decomposition of an ionic liquid according to the present invention, it was confirmed that the decomposition initiation temperature was significantly lowered and the low-temperature decomposition activity was excellent. . In addition, it has heat resistance that does not cause damage or deformation even when fired at high temperatures, and exhibits excellent physical properties without reducing decomposition efficiency. In addition, as in Comparative Example 2, when a metal coating layer is formed on a metal foam rather than a porous ceramic structure, Even when carried out under the same conditions as in Example 1, it was confirmed that the effect of reducing the metal loading amount and the decomposition initiation temperature was insignificant.

In addition, as in Comparative Examples 3 and 4, when the metal coating layer containing only the platinum-based metal was formed, it was confirmed that the reduction in the decomposition initiation temperature hardly occurred, and as in Comparative Example 5, the metal coating layer containing only copper In this case, as shown in FIG. 2 , the catalyst pores were clogged and distorted, and the shape was deformed, and decomposition of the ionic liquid did not occur, making it difficult to use as a catalyst for decomposing the ionic liquid.

In the present invention, as described above been described by the specific details and exemplary embodiments and the drawing, which only be provided to assist the overall understanding of the present invention, the present invention is not limited to the embodiment of the present invention If you grow up with common knowledge in the field you belong to, various modifications and variations are possible from these descriptions.

Therefore, the idea according to this invention should not be limited to the described embodiments and should not be defined, and not only the claims described later, but also all the variations in the claims that are equivalent to or equivalent to the claimed ones. will be.

Claims (10)

porous ceramic structure; and
a metal coating layer formed on the porous ceramic structure and including a platinum-based metal and copper;
A catalyst for decomposition of an ionic liquid comprising a. The method of claim 1,
The platinum-based metal is platinum or iridium, a catalyst for decomposition of an ionic liquid. The method of claim 1,
The porous ceramic structure is a cordierite monolith catalyst for decomposition of an ionic liquid. The method of claim 1,
The supported amount of the platinum-based metal is 0.1 to 30% by weight based on the total weight of the catalyst for decomposition of the ionic liquid,
The supported amount of copper is 5 to 60% by weight based on the total weight of the catalyst for decomposing the ionic liquid. A method for decomposing an ionic liquid by inducing a decomposition reaction by contacting a catalyst for decomposition of an ionic liquid comprising a metal coating layer including a platinum-based metal and copper on a porous ceramic structure with the ionic liquid. 6. The method of claim 5,
wherein the ionic liquid is a single propellant. a) forming a precursor coating layer by immersing the porous ceramic structure in a precursor solution containing a platinum-based metal precursor and a copper precursor;
b) forming a metal coating layer by firing the porous ceramic structure on which the precursor coating layer is formed;
A method for producing a catalyst for decomposition of an ionic liquid comprising a. 8. The method of claim 7,
The method for producing a catalyst for decomposition of an ionic liquid is that the calcination is carried out at 1,000 ° C. 8. The method of claim 7,
The platinum-based metal precursor is a method for producing a catalyst for decomposition of an ionic liquid, which is a platinum precursor or an iridium precursor. 8. The method of claim 7,
The porous ceramic structure is a method for producing a catalyst for decomposition of an ionic liquid to further perform a pretreatment step before step a).

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