KR100985055B1 - Phosphorus-containing transition metal catalyst for hydrogen generation from hydrolysis reaction of ammonia-borane and its preparation method - Google Patents

Abstract

The present invention relates to a transition metal catalyst containing phosphorus and a method for producing the same. More specifically, electroplating of a phosphorus-doped transition metal-phosphorus (P) catalyst having high catalytic efficiency while improving the rate of hydrogen evolution through hydrolysis of ammonia-borane (NH ₃ BH ₃ ) It is produced by the electroless plating method. The transition metal-phosphorus catalyst of the present invention exhibits higher hydrogen evolution rates than precious metal catalysts such as ruthenium (Ru) or platinum (Pt).

The present invention has a high catalytic activity in the hydrolysis reaction of ammonia-borane and thus can replace precious metal catalysts such as platinum or ruthenium, and provide a transition metal catalyst having a simple process and high binding force between the substrate and the catalyst particles. .

Transition Metals, Phosphorus, Ammonia-Borrain, Hydrolysis Reaction, Hydrogen Generation Rate

Description

Transition metal based catalysts including phosphorus for hydrogen generation from hydrolysis of ammonia-borane and manufacturing method

The present invention relates to a transition metal catalyst containing phosphorus and a method for producing the same. More specifically, electroplating of a phosphorus-doped transition metal-phosphorus (P) catalyst having high catalytic efficiency while improving the rate of hydrogen evolution through hydrolysis of ammonia-borane (NH ₃ BH ₃ ) It is produced by the electroless plating method. The transition metal-phosphorus catalyst of the present invention exhibits a higher hydrogen evolution rate than a noble metal catalyst such as ruthenium (Ru) or platinum (Pt), thereby providing a transition metal-phosphorus catalyst and a method of preparing the same.

Currently, hydrogen storage includes gas storage, liquid storage, and solid storage. The dual gas storage method has a problem that the system is large due to the small storage capacity. The liquid hydrogen storage method has a higher storage density (70g / ℓ) than the compressor body storage method, but it is a method of liquefying and storing hydrogen at -235 ℃ below the liquefaction point, which consumes a lot of energy and does not vaporize during storage. Due to the problem of using a large cryogenic vessel, it is not suitable for hydrogen storage in terms of economy. The hydrogen storage alloy, which is a solid storage method, should also be preceded by the development of a hydrogen storage alloy having excellent hydrogen storage capacity and hydrogenation reaction rate. In addition, the study of carbon-based hydride, which is being actively researched in recent years, is a situation in which the reproducibility and reliability of the system are still insufficient.

The prior art related to the present invention is USP 6,683,025 (process for making a hydrogen generation catalyst) is a system for generating hydrogen by reacting boron hydride and water, the boron hydride should be stored in an alkaline solution to store the self-hydrolysis reaction. It is stored safely without causing it. However, since the present invention utilizes a hydrolysis reaction of ammonia borane, hydrogen storage is easier than boron hydride because an alkaline solution is not required for storage. In addition, USP 6,358,488 (method for generation of hydrogen gas) using a noble metal catalyst such as Ru, Pt for hydrogen generation in the boride hydride, in the present invention by adding P to the transition metal such as Co through the electrochemical method ammonia bore Since the transition metal-based catalyst having a high hydrogen generation rate from phosphorus is prepared, the technical configuration is different from the prior art.

A high-performance hydrogen generation system (Transition metal-catalyzed dissociation and hydrolysis, published by Manish Chandra, Qiang Xu), J. Power Source 156 (2006) 190) is described in Pt, Rh, Catalysts prepared using noble metals of Pd, Ag, Au and catalysts using Co, W were prepared and tested for hydrogen evolution in ammonia borane solution. Pt / C catalysts using Pt outperformed the other catalysts with much higher hydrogen evolution rates.

Catalytic activities of non-noble metals for hydrogen generation from aqueous ammonia borane at room temperature, published by Qiang Xu, Mnish Chandra. Power Source 163 (2006) 364) developed low-cost metals such as Co, Ni, Cu, Fe, and Al ₂ O ₃ to develop low-cost catalysts as hydrogen-generating catalysts in ammonia borane. By increasing the surface area of the catalyst, the catalyst using Ni and Co had a much higher hydrogen generation rate than that of Cu and Fe, but the hydrogen generation rate was less than that of precious metals such as Pt, Ph and Ru. These prior arts also differ in technical configuration from the present invention.

The present invention relates to a transition metal-based catalyst containing phosphorus for hydrogen generation from the hydrolysis reaction of ammonia-borane and a method for producing the same.

Boron hydrides such as NaBH ₄ , LiBH ₄ and KBH ₄ have a very high hydrogen storage density of 10 wt% or more, and are easily transported and transported since they can be stored in a liquid state. Therefore, the fuel cell hydrogen storage system, the fuel storage system for hydrogen vehicles, the driving source of electric vehicles and small electronic devices, etc. can be applied to a variety of applications as the most suitable storage medium for various industrial fields using hydrogen energy. Boron hydride has the property of generating hydrogen through hydrolysis reaction with water (see Scheme (1) below).

NaBH ₄ + 2H ₂ O → NaBO ₂ + 4H ₂ ...... Reaction Scheme (1)

However, boron hydrides also react easily with moisture in the air, which must be stored in highly alkaline solutions with a pH above 13. These high concentrations of alkaline solutions cause severe corrosion to storage containers and are very harmful when in contact with humans. On the other hand, since ammonia-boraine does not react with water to cause a hydrolysis reaction, it can be safely stored in neutral water. In addition, it theoretically has a high hydrogen storage density of 19.6 wt.%, And hydrogen is generated through pyrolysis and hydrolysis reactions. In particular, the hydrolysis reaction (see Scheme (2) below) has a great advantage of generating a large amount of hydrogen at 8.6 wt.% Even at room temperature.

_{NH 3 BH 3 + 2H 2 O} → NH 4 + + BO 2 - + 3H 2 ...... reaction (2)

When hydrogen is generated from ammonia-boraine safely stored in neutral water, hydrogen can be generated through catalysts such as platinum (Pt), rhodium (Rh), and ruthenium (Ru), so it is very easy to control the amount of hydrogen generated. It has one advantage. However, such a noble metal catalyst is not only complicated in manufacturing process and low in economic efficiency, but also has low binding strength with the catalyst support, making it difficult to repeatedly use the catalyst. Therefore, it is necessary to develop a transition metal catalyst having a high catalytic activity for the hydrolysis reaction of ammonia-borane, but no studies on this have been reported.

The present invention has a high activity in the hydrolysis reaction of ammonia-borein, in order to replace a noble metal catalyst such as platinum (Pt) or ruthenium (Ru), a simple process and a high binding strength of the substrate and the catalyst particles An object of the present invention is to provide a catalyst and a method for preparing the same.

The present invention investigates the hydrogen evolution characteristics of the transition metal-phosphorus (P) catalyst containing phosphorus (P) in the transition metal, and analyzes the effect of the catalyst manufacturing process on the composition and catalyst activity of the ammonia-borane. The present invention intends to develop a high performance hydrogen transition metal catalyst having high activity in the hydrolysis reaction.

It is to prepare a transition metal-phosphorus catalyst to which phosphorus is added with high catalytic efficiency while improving the hydrogen generation rate through the hydrolysis reaction of ammonia-borane.

Phosphorus-containing transition metal catalysts capable of generating hydrogen through the hydrolysis reaction of ammonia-borane of the present invention have a higher catalytic activity than conventional noble metal catalysts, and thus can rapidly generate hydrogen in ammonia-borane. have.

In the present invention, in the preparation of the transition metal catalyst containing phosphorus (P) by electroplating, the catalyst support is immersed in the plating solution and the current is applied, and the catalyst support and the catalyst particles can be prepared in large quantities. There is a high bond strength with. The same transition metal catalyst can also be obtained by electroless plating.

The present invention represents a transition metal-phosphorus catalyst containing phosphorus (P) capable of generating hydrogen by hydrolysis reaction of ammonia-borane.

In the transition metal-phosphorus catalyst containing phosphorus (P), the transition metal is cobalt (Co), nickel (Ni), titanium (Ti), vanadium (V), chromium (Cr), manganese (Mn), iron ( Fe), copper (Cu), zinc (Zn) and at least one selected from the group of the compound containing the above metal.

In the transition metal-phosphorus catalyst containing phosphorus (P) above, phosphorus (P) may be contained in an amount of 1 to 20 wt%.

The present invention shows a method for producing a transition metal-phosphorus catalyst containing phosphorus (P) capable of generating hydrogen by hydrolysis reaction of ammonia-borane.

The method for preparing a transition metal-phosphorus catalyst containing phosphorus (P) capable of generating hydrogen by the hydrolysis reaction of ammonia-borane of the present invention is an electroplating solution comprising a transition metal source and a phosphorus (P) source. After having a cathode and an anode on the anode, a transition metal-phosphorus catalyst containing phosphorus (P) capable of generating hydrogen in ammonia-boron may be prepared by applying an electric current and plating.

In the above, the cathode may be copper or nickel, and the anode may be the same as the transition metal catalyst containing phosphorus.

The transition metal source is CoSO ₄ , CoCl ₂ , Co (NO ₃ ) ₂ , NiSO ₄ , NiCl ₂ , Ni (NO ₃ ) ₂ , FeSO ₄ , FeCl ₂ , Fe (NO ₃ ) ₂ , CuSO ₄ , CuCl ₂ , Cu (NO ₃ ) ₂ , CrSO ₄ , CrCl ₂ , Cr (NO ₃ ) ₂ , MnSO ₄ , MnCl ₂ , Mn (NO ₃ ) ₂ , Any one or more selected from ZnSO ₄ , ZnCl ₂ and Zn (NO ₃ ) ₂ may be used.

As the phosphorus (P) source, phosphorus (P) or a compound containing phosphorus (P) may be used.

In the phosphorus-containing transition metal-phosphorus catalyst, phosphorus (P) may be plated by applying a current to contain 1 to 20 wt% of phosphorus-containing transition metal-phosphorus catalyst.

The present invention represents another method for preparing a transition metal-phosphorus catalyst containing phosphorus (P) capable of generating hydrogen by hydrolysis reaction of ammonia-borane.

Another method for preparing a transition metal-phosphorus catalyst containing phosphorus (P) capable of generating hydrogen by the hydrolysis reaction of ammonia-borane of the present invention is a solution containing a transition metal source and a phosphorus (P) source. The transition metal support may be electroless plated to prepare a transition metal-phosphorus catalyst containing phosphorus (P) capable of generating hydrogen in ammonia-borane.

The pH of the electroless plating solution is adjusted to 9 to 14, the plating time is 30 to 90 ℃, the plating time is 20 seconds to 70 minutes by electroless plating to the transition metal containing phosphorus (P)- Phosphorus catalyst can be prepared.

Hereinafter, the present invention will be described in more detail.

The present invention represents a transition metal catalyst containing phosphorus (P) capable of generating hydrogen in ammonia-borane.

The phosphorus-containing transition metal catalyst of the present invention can generate hydrogen from ammonia-borane.

Unlike boron hydride, ammonia-borane does not react with water to cause a hydrolysis reaction, and thus it is not necessary to store it in an alkaline solution (water in which at least one selected from NaOH and KOH is dissolved). Therefore, the transition metal catalyst containing phosphorus of the present invention may generate hydrogen in the ammonia solution, for example, a solution in which water and ammonia are mixed.

In the transition metal catalyst containing phosphorus (P) of the present invention, the transition metal is cobalt (Co), nickel (Ni), titanium (Ti), vanadium (V), chromium (Cr), manganese (Mn), iron (Fe). ), Copper (Cu), zinc (Zn) and any one or more selected from the compound containing the above metal can be used. As an example of the transition metal catalyst containing phosphorus (P) of the present invention, a cobalt (Co) -phosphorus (P) catalyst containing phosphorus, a nickel (Ni) -phosphorus (P) catalyst containing phosphorus, Titanium (Ti) -phosphorus (P) catalyst, vanadium (V) -phosphorus (P) catalyst with phosphorus, chromium (Cr) -phosphorus (P) catalyst with phosphorus, manganese (Mn) with phosphorus ) -Phosphorus (P) catalyst, phosphorus-containing iron (Fe) -phosphorus (P) catalyst, phosphorus-containing copper (Cu) -phosphorus (P) catalyst, phosphorus-containing zinc (Zn) -phosphorus (P) ) Catalyst, phosphorus-containing cobalt-nickel-phosphorus (Co-Ni-P) catalyst, phosphorus-containing cobalt-copper-phosphorus (Co-Cu-P) catalyst, phosphorus-containing cobalt-zinc-phosphorus (Co One or more selected from -Zn-P) catalysts may be used as a catalyst to generate hydrogen from the hydrolysis reaction of ammonia-borane.

In the present invention, the transition metal catalyst containing phosphorus (P) contains 1 to 20 wt.% Of phosphorus (P). When the phosphorus content is less than 1wt.% In the transition metal catalyst containing phosphorus (P) of the present invention, the improvement of hydrogen generation from ammonia-boron is insignificant compared to the ordinary transition metal catalyst, and phosphorus (P) is contained. If the content of phosphorus in the transition metal catalyst is more than 20wt%, there is a fear that the hydrogen generation from the ammonia-borane is reduced by the excess phosphorus (P) content. Therefore, the transition metal catalyst containing phosphorus (P) of the present invention preferably contains 1 to 20 wt% of phosphorus (P).

The transition metal catalyst containing phosphorus (P) capable of generating hydrogen in the ammonia-borane of the present invention can be prepared using electroplating or electroless plating.

In the present invention, when preparing a transition metal catalyst containing phosphorus (P) by using electroplating, it is possible to mass-produce the catalyst support by immersing the catalyst support in a plating solution and applying a current to the catalyst support. There is an advantage of high bonding strength with the catalyst particles.

When the electroless plating is used in the present invention, mass production is possible as in the above electroplating, the bonding force between the catalyst support and the catalyst particles is high, and in particular, even when the catalyst support is an insulator, plating is possible.

An example of preparation of a transition metal catalyst containing phosphorus (P) capable of generating hydrogen in the ammonia-borane of the present invention using electroplating is as follows.

First, the support of the transition metal catalyst containing phosphorus (P) is pretreated, washed, electroplated, washed, and then dried.

The support of the transition metal catalyst may be a metal, a porous material, a polymer (polymer). In this case, copper (Cu) or nickel (Ni) may be used as one example of the metal, and nickel foam or copper foam may be used as one example of the porous material. As an example of the polymer, an ion exchange resin can be used.

In the above, the support of the transition metal catalyst may be pretreated before electroplating to remove impurities from the surface of the support. As an example of such a pretreatment, when the support is used as copper, a pretreatment is performed for 30 to 90 seconds, preferably 60 seconds, with 10 wt% sulfuric acid (H ₂ SO ₄ ) to remove impurities from the copper surface.

The support of the transition metal catalyst subjected to the pretreatment above is washed with purified water and electroplated.

Electroplating may use the same transition metal as the transition metal catalyst as the anode by using the support of the transition metal catalyst as a reduction electrode. For example, in the case of the cobalt-phosphorus catalyst in which the transition metal catalyst to be manufactured contains phosphorus, cobalt may be used as the anode. In the case of the nickel-phosphorus catalyst in which the transition metal catalyst to be manufactured contains phosphorus, the anode is nickel. Can be used. In addition to these, a noble metal such as platinum (Pt) can be used as the anode.

In the preparation of the transition metal catalyst containing phosphorus using the electroplating can be prepared by using a constant current method. At this time, the reduction current density during electroplating using the constant current method is 0.01A / cm ² ~ 10A / cm ² and the plating time is 20 seconds ~ 70 minutes, preferably 0.01A / cm ² ~ 1A / cm ² By plating for 300 seconds to 3600 seconds (60 minutes), a transition metal catalyst containing 1 to 20 wt% of phosphorus (P) can be prepared.

In preparing the transition metal catalyst containing phosphorus using electroplating as the source of the transition metal (co) as cobalt (Co), nickel (Ni), titanium (Ti), vanadium (V), chromium (Cr), manganese Any one or more selected from (Mn), iron (Fe), copper (Cu), zinc (Zn), and the compound containing the above metal can be used. CoSO as an example of such a transition metal source₄, CoCl₂, Co (NO₃)₂, NiSO₄, NiCl₂, Ni (NO₃)₂, FeSO₄, FeCl₂, Fe (NO₃)₂, CuSO₄, CuCl₂, Cu (NO₃)₂, CrSO₄, CrCl₂, Cr (NO₃)₂, MnSO₄, MnCl₂, Mn (NO₃)₂, ZnSO₄, ZnCl₂, Zn (NO₃)₂Any one or more selected from among them can be used. The content of the transition metal may be selectively used depending on the transition metal catalyst containing phosphorus to be prepared. For example, when the phosphorus-containing transition metal catalyst is prepared by using electroplating, the content of the transition metal source may be used in an amount of 0.01 to 2 mol (mole) per 1 liter (L) of the electroplating solution.

In the above-described production of phosphorus-containing transition metal catalyst using electroplating, phosphorus (P) may be used as a source of phosphorus or phosphorus-containing compounds. One example of such a phosphorus source may be any one or more selected from NaH ₂ PO ₂ H ₂ O, H ₃ PO ₃ , and H ₃ PO ₄ . The content of the phosphorus source may be selectively used depending on the transition metal catalyst containing phosphorus to be prepared. For example, when preparing a transition metal catalyst containing phosphorus using electroplating, the content of phosphorus source may be used in an amount of 0.01 to 2 mol (mole) per 1 liter (L) of the electroplating solution.

When preparing a transition metal catalyst containing phosphorus using the electroplating in the above, additives other than the transition metal source and phosphorus source may be used. These additives allow the plating of the transition metal containing phosphorus to proceed uniformly, and act as a buffer to suppress rapid pH changes during plating. In the above additives, 0.01 to 4 moles may be used per 1 liter (L) of the electroplating solution. As an example of the additive in the present invention, any one or more selected from C ₆ H ₅ Na ₃ O ₇ · 2H ₂ O, (NH ₄ ) ₂ SO ₄ , H ₃ BO _3, NH ₂ CH ₂ COOH can be used. At this time C ₆ H ₅ Na ₃ O ₇ .2H ₂ O may be used in an amount of 0.01 to 2 moles per 1 liter (L) of the electroplating solution, and (NH ₄ ) ₂ SO ₄ may be 0.01 to 1 liter of the electroplating solution. to 2 can be used to drive, it is possible to use 0.01 to 2 mole of the H ₃ BO ₃ in the electroplating solution 1 liters (L), for the NH ₂ CH ₂ COOH to the electroplating solution 1 liters (L) 0.01~ 2 moles can be used. In the present invention, when two or more of the above additives are used, the total content of the additives in the electroplating solution may be used such that 4 mol, preferably 2 mol or less, per 1 liter (L) of the electroplating solution.

An example of preparation of a transition metal catalyst containing phosphorus (P) capable of generating hydrogen in the ammonia-borane of the present invention using an electroless plating is as follows.

First, the support of the transition metal catalyst containing phosphorus is cleaned by pretreatment, electroless plated, and then washed and dried.

The support of the transition metal catalyst may be a metal, a porous material, a polymer (polymer). In this case, copper or nickel may be used as one example of the metal, and nickel foam or copper foam may be used as one example of the porous material. One example of the polymer may be an ion exchange resin.

In the above, the support of the transition metal catalyst may be pretreated before electroless plating to remove impurities from the surface of the support. As an example of such pretreatment, when the support is used as copper, a pretreatment is performed for 60 seconds with 10 wt% sulfuric acid to remove impurities on the copper surface.

The support of the transition metal catalyst pretreated above was washed with purified water, immersed in 1 g / L SnCl ₂ + 1 cc / L HCl solution for 3 minutes, and in 0.1 g / L PdCl ₂ +1 cc / LHCl solution for 2 minutes. Perform plating.

In the electroless plating, the phosphorus source described below serves as a reducing agent, and the electroless plating proceeds. In this case, the phosphorus source may serve as a reducing agent by appropriately adjusting pH and temperature. In order for the phosphorus source to act as a reducing agent in the electroless plating of the present invention, the pH of the electroless plating solution is adjusted to 9 to 14, the plating temperature is 30 to 90 ° C., and the plating time is 20 seconds to 70 minutes. Preferably, the pH of the electroless plating solution is 10 to 13, and the transition metal containing 1 to 20 wt% of phosphorus (P) is subjected to electroless plating at a temperature of 50 to 80 ° C. for 45 seconds to 3600 seconds (60 minutes). Catalysts can be prepared.

As the source of the transition metal in the production of the transition metal catalyst containing phosphorus using the electroless plating, cobalt (Co), nickel (Ni), titanium (Ti), vanadium (V), chromium (Cr), and manganese ( Mn), iron (Fe), copper (Cu), zinc (Zn) and any one or more selected from the compound containing the above metal can be used. Examples of such transition metal sources are CoSO ₄ , CoCl ₂ , Co (NO ₃ ) ₂ , NiSO ₄ , NiCl ₂ , Ni (NO ₃ ) ₂ , FeSO ₄ , FeCl ₂ , Fe (NO ₃ ) ₂ , CuSO ₄ , CuCl ₂ , Cu (NO ₃ ) ₂ , CrSO ₄ , CrCl ₂ , Cr (NO ₃ ) ₂ , MnSO ₄ , MnCl ₂ , Mn (NO ₃ ) ₂ , Any one or more selected from ZnSO ₄ , ZnCl ₂ , Zn (NO ₃ ) ₂ may be used. The content of the transition metal source may be selectively used depending on the transition metal catalyst containing phosphorus to be prepared. For example, when preparing a transition metal catalyst containing phosphorus using electroless plating, the content of the transition metal source may be used in an amount of 0.01 to 2 mol (mole) based on 1 liter (L) of the electroless plating solution.

When preparing a transition metal catalyst containing phosphorus by using electroless plating, phosphorus or a compound containing phosphorus may be used as the source of phosphorus. One example of such a phosphorus source may be any one or more selected from NaH ₂ PO ₂ H ₂ O, H ₃ PO ₃ , and H ₃ PO ₄ . The content of the phosphorus source may be selectively used depending on the transition metal catalyst containing phosphorus to be prepared. For example, when preparing a transition metal catalyst containing phosphorus using electroless plating, the content of phosphorus source may be 0.01 to 2 mol based on 1 liter of the electroless plating solution.

When preparing a transition metal catalyst containing phosphorus using the electroless plating method, an additive other than the transition metal source and phosphorus source may be used. These additives allow the plating of the transition metal containing phosphorus to proceed uniformly, and act as a buffer to suppress rapid pH changes during plating. In the above additives, 0.01 to 4 moles may be used per 1 liter of electroless plating solution. As an example of the additive in the present invention, any one or more selected from C ₆ H ₅ Na ₃ O ₇ · 2H ₂ O, (NH ₄ ) ₂ SO ₄ , H ₃ BO _3, NH ₂ CH ₂ COOH can be used. At this time 0.01 to 2 moles of C ₆ H ₅ Na ₃ O ₇ .2H ₂ O may be used per 1 liter of the electroless plating solution, and (NH ₄ ) ₂ SO ₄ may be 0.01 to 1 liter (L) of the electroless plating solution. to 2 mol (mole) can be used, even if the electroless H ₃ BO ₃ may be used from 0.01 to 2 mol with respect to the gold solution 1 liters, NH ₂ CH ₂ COOH by electroless plating with respect to the gold solution 1 liters 0.01 to 2 mol Can be used. In the present invention, when two or more of the above additives are used, the total content of the additives in the electroless plating solution may be 4 mol, preferably 2 mol or less, per 1 liter of the electroless plating solution.

Hereinafter, the contents of the present invention will be described in detail through comparative examples and examples. However, these are intended to explain the present invention in more detail, and the scope of the present invention is not limited thereto.

Comparative Example 1

In order to compare the hydrogen evolution characteristics of the cobalt-phosphorus catalyst with the noble metal catalyst, a platinum (Pt) catalyst supported on a commercially available activated carbon was used. The weight ratio of platinum (Pt) catalyst supported on activated carbon is 10 wt.%.

Comparative Example 2

In order to compare the hydrogen evolution characteristics of the cobalt-phosphorus catalyst with the noble metal catalyst, a ruthenium (Ru) catalyst supported on commercially available alumina (Al ₂ O ₃ ) was used. The ruthenium (Ru) catalyst weighs 10 mg except the weight of the supporting alumina (Al ₂ O ₃ ).

≪ Example 1 >

The electroplating was carried out in the composition of Table 1 below to prepare a cobalt-in catalyst.

Copper was used as the cathode and cobalt-phosphorus catalyst was prepared by the constant current method using cobalt as the anode. At this time, the reduction current density was 0.05A / cm ² and the plating time was electroplated to 300 seconds to prepare a cobalt-in catalyst.

The cobalt source used CoCl ₂ .6H ₂ O and the phosphorus source used NaH ₂ PO ₂ · H ₂ O in the preparation of the cobalt-phosphorus catalyst.

Table 1. Cobalt-Phoss Catalyst Composition

Furtherance density CoCl ₂ · 6H ₂ O 0.1M NaH ₂ PO ₂ · H ₂ O 0.8M NH ₂ CH ₂ COOHH ₂ O 0.6M Water 1 liter (L)

<Example 2>

Electroless plating was carried out in the composition of Table 1 to prepare a cobalt-in catalyst.

In order to accelerate the plating, the pH of 12.5 was adjusted by adding 0.8 mol NaOH to 1 L of the composition shown in Table 1. Copper was used as the cathode, the plating temperature was 60 ℃, the plating time was 8 minutes to prepare a cobalt-phosphorus catalyst.

The cobalt source used CoCl ₂ .6H ₂ O and the phosphorus source used NaH ₂ PO ₂ · H ₂ O in the preparation of the cobalt-phosphorus catalyst.

<Test Example 1>

The platinum / carbon catalyst of Comparative Example 1, the ruthenium catalyst of Comparative Example 2, in the above (2wt% NH ₃ BH ₃ + water) solution (NH ₃ BH ₃ weight: 2 g, water weight: 98 g) at 30 ° C Hydrogen was generated by immersing the cobalt-in catalysts prepared in Examples 1 and 2, and the hydrogen evolution rate was measured through a gas flow meter, and the results are shown in FIG.

The catalyst material weights of all the above catalysts are all equal to 10 mg.

1, hydrogen evolution rates of the platinum catalyst (▼), the ruthenium catalyst (▲), the electroplated cobalt-phosphorus catalyst (■), and the electroless plated cobalt-phosphorus catalyst (●) were 20.1 ml / min.g, respectively. -catalysts, 5.95 ml / min.g-catalysts, 37.5 ml / min.g-catalysts, 14.3 ml / min.g-catalysts. The ruthenium catalyst showed very low catalytic efficiency for the hydrolysis reaction of ammonia-borane, but the electroplated cobalt-phosphate catalyst showed about 6.3 times higher hydrogen generation rate than ruthenium catalyst and 1.8 times higher than platinum catalyst. The electroplated cobalt-phosphorus catalyst showed higher hydrogen evolution rate than ruthenium but slightly lower than platinum.

From this, it was confirmed that the transition metal catalyst to which phosphorus was added, particularly cobalt-phosphorus, had high catalytic activity in the ammonia-borane hydrolysis reaction.

<Test Example 2>

Figure 2 shows the effect of ammonia-borane solution temperature on the hydrogen evolution rate when using an electroplated cobalt (Co) -phosphorus (P) catalyst.

Copper was used as a composition and a reducing electrode of Table 1 of Example 1, and a cobalt-in catalyst was prepared by a constant current method using cobalt as an anode. At this time, the reduction current density was 0.05A / cm ² and the time was 5 minutes to prepare a cobalt-phosphorus catalyst.

The hydrogen evolution rate was measured by immersing the cobalt-phosphate catalyst prepared above in a 2.wt% NH ₃ BH ₃ + water solution at 30 ° C., and the temperature of the ammonia-borane solution increased from 30 ° C. to 50 ° C. The mean hydrogen evolution rate increased from 22.1 ml / min.g-catalysts to 38.4 ml / min.g-catalysts. From the graph of FIG. 3, the activation energy was measured, and found to be 21.6 kJ / mol. This is similar to the activation energy of existing noble metal catalysts.

<Test Example 3>

Figure 4 shows the effect of ammonia-borane solution temperature on the hydrogen evolution rate when using an electroplated cobalt (Co) -phosphorus (P) catalyst.

In order to accelerate the plating, the pH of 12.5 was adjusted by adding 0.8 mol NaOH to 1 L of the composition of Table 1. Copper was used as the cathode, the plating temperature was 60 ℃, the plating time was 8 minutes to prepare a cobalt-in catalyst.

The hydrogen evolution rate was measured by immersing the cobalt-phosphate catalyst prepared above in a 2.wt% NH ₃ BH ₃ + water solution at 30 ° C., and the temperature of the ammonia-borane solution increased from 30 ° C. to 50 ° C. The mean hydrogen evolution rate increased from 14.1 ml / min.g-catalysts to 31.1 ml / min.g-catalysts. From this, the graph of FIG. 5 was drawn, and the activation energy was measured. As a result, it was found to be 29.5 kJ / mol. This is slightly larger than the activation energy of conventional noble metal catalysts.

From the above results, it can be seen that the cobalt catalyst to which phosphorus is added has higher hydrogen generation characteristics than the cobalt catalyst. Phosphorus added titanium (Ti), vanadium (V), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn) Alloy system such as Co-Ni-P, Co-Cu-P, Co-Zn-P, etc. can also be applied as a hydrogen generating catalyst through hydrolysis reaction of ammonia-borane.

As described above, the present invention has been described with reference to preferred embodiments and test examples, but a person skilled in the art will appreciate that the present invention is within the scope without departing from the spirit and construction of the present invention as set forth in the following claims. It will be understood that various modifications and changes can be made.

1 shows an electroplated cobalt (Co) -phosphorus (P) catalyst, an electroplated cobalt (Co) -phosphorus (P) catalyst, 10 wt.% Platinum / carbon (10 wt.% Pt / C), ruthenium (Ru ) Is a graph showing the effect of the catalyst on the hydrogen evolution characteristics of ammonia-borane (NH ₃ BH ₃ ).

Figure 2 is a graph showing the hydrogen evolution rate according to the effect of ammonia-borane (NH ₃ BH ₃ ) solution temperature when using an electroplated cobalt (Co) -phosphorus (P) catalyst.

3 is a graph for obtaining activation energy of an electroplated cobalt (Co) -phosphorus (P) catalyst using the results of FIG. 2.

Figure 4 is a graph showing the hydrogen evolution rate according to the effect of ammonia-borane (NH ₃ BH ₃ ) solution temperature when using an electroplated cobalt (Co) -phosphorus (P) catalyst.

FIG. 5 is a graph for obtaining activation energy of an electroplated cobalt (Co) -phosphorus (P) catalyst using the results of FIG. 4.

6 is a scanning electron micrograph showing the surface shape of the electroplated cobalt (Co) -phosphorus (P) catalyst.

FIG. 7 is a scanning electron micrograph showing the surface shape of an electroplated cobalt (Co) -phosphorus (P) catalyst.

Claims (13)

A transition metal-phosphorus catalyst containing 1 to 20 wt% of phosphorus (P) capable of generating hydrogen by a hydrolysis reaction of ammonia-borane (H ₃ N-BH ₃ ). In the transition metal-phosphorus catalyst, the transition metal is cobalt (Co), nickel (Ni), titanium (Ti), vanadium (V), chromium (Cr), manganese (Mn), iron (Fe), copper (Cu) or At least one selected from zinc (Zn). delete delete After providing a reduction electrode and an anode in an electroplating solution including a transition metal source and a phosphorus (P) source, phosphorus capable of generating hydrogen by ammonia-borane hydrolysis reaction is plated by applying current. A method for producing a catalyst having a transition metal-containing P) of 1 to 20 wt%. The method of claim 4, wherein the cathode is copper or nickel, and the anode is the same as the transition metal catalyst containing phosphorus. The method of claim 4, wherein the transition metal source is CoSO ₄ , CoCl ₂ , Co (NO ₃ ) ₂ , NiSO ₄ , NiCl ₂ , Ni (NO ₃ ) ₂ , FeSO ₄ , FeCl ₂ , Fe (NO ₃ ) ₂ , CuSO ₄ , CuCl ₂ , Cu (NO ₃ ) ₂ , CrSO ₄ , CrCl ₂ , Cr (NO ₃ ) ₂ , MnSO ₄ , MnCl ₂ , Mn (NO ₃ ) ₂ , ZnSO ₄ , ZnCl ₂ Or Zn (NO ₃ ) _2. A process for producing a transition metal-phosphorus catalyst, characterized in that at least one selected from. The method of claim 4, wherein the phosphorus (P) source is phosphorus (P) or a compound containing phosphorus (P). delete 1 to 20 wt% of phosphorus (P) capable of generating hydrogen by hydrolysis of ammonia-borane by electroplating after washing the transition metal support in a solution containing a transition metal source and a phosphorus (P) source Process for preparing a transition metal-phosphorus catalyst containing%. 10. The method according to claim 9, wherein the pH of the electroless plating solution is adjusted to 9 to 14, the plating temperature is 30 to 90 ℃, the plating time is characterized in that the electroless plating for 20 seconds to 70 minutes Process for producing a transition metal-phosphorus catalyst containing P). 10. The method for preparing a transition metal-phosphorus catalyst containing phosphorus (P) according to claim 9, wherein the transition metal support is any one selected from a metal, a porous material and a polymer. The method of claim 9, wherein the additive during plating is used at least any one selected from C ₆ H ₅ Na ₃ O ₇ 2H ₂ O, (NH ₄ ) ₂ SO ₄ , H ₃ BO ₃ or NH ₂ CH ₂ COOH. Process for producing a transition metal-phosphorus catalyst containing phosphorus (P). The process for producing a transition metal-phosphorus catalyst containing phosphorus (P) according to claim 12, wherein the additive is used in an amount of 0.01 to 4 moles per 1 liter of the electroplating solution.

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