JP2000272912A - Production of hydrogenated fullerene using catalyst of nickel supported with active alumina and recovery of hydrogen from hydrogenated fullerene - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for efficiently producing hydrogenated fullerene as a material for hydrogen storage and to provide a method for recovering hydrogen from the hydrogenated fullerene. SOLUTION: A transformation method comprises transforming C60 fullerene into hydrogenated fullerene and vice versa both in the presence of a Ni/Al2O3 catalyst where active alumina is impregnated with nickel to support it. This method for producing hydrogenated fullerene comprises utilizing a transformation reaction in the presence of a Ni/Al2O3 catalyst where active alumina is impregnated with nickel to support it in order to transform C60 fullerene into hydrogenated fullerene C60H36 under a mildly hydrogenating condition at high efficiency and selectivity.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing hydrogenated fullerene and a method for recovering hydrogen from the hydrogenated fullerene. More specifically, the present invention relates to Ni / Al ₂ in which activated alumina is impregnated and supported on nickel. O ₃ by using a conversion reaction of the fullerene with the catalyst, in high efficiency and high selectivity for producing a hydrogen storage material comprising a hydrogenated fullerene by converting C ₆₀ fullerene C ₆₀ H ₃₆ in the process and on the catalyst the hydrogenation fullerene by utilizing a reverse reaction to a method for recovering hydrogen into a C ₆₀ fullerene.

[0002]

[Prior Art] If we regard this century as the “oil age”,
The 21st century is the "age of hydrogen." It is clear from the fire that the depletion of fossil resources such as oil and coal will become a problem in the near future due to the increase in energy consumption. I have to go. In other words, it is no exaggeration to say that companies that control technologies related to the production, transport, storage, and utilization of hydrogen, etc. will survive the 21st century. In the automotive industry, electric vehicles that use both storage batteries and engines have already been put into practical use, but the introduction of fuel cell vehicles that use hydrogen is soon approaching. How to use hydrogen, a clean energy source that does not emit carbon dioxide, which is a cause of global warming, will surely become a central issue in the next-generation high-tech industry.

The present inventors have narrowed the target to "transport and storage of hydrogen" among hydrogen-related technologies, and have been conducting research and development with emphasis on developing a light storage material. As a storage material, a material utilizing the hydrogen embrittlement of a so-called metal compound such as lanthanum nickel hydride (LaNi ₅ H ₆ ) has been well studied. However, since these are metals, at most 1 wt. % Of hydrogen (1.4 wt.% For LaNi ₅ H ₆ ). It is in principle difficult to desire a higher storage rate as long as a metal material is used. On the other hand, the carbon material is constructed only from carbon having a mass number of 12, and if this can be used as a storage material, hydrogen may be stored at a ratio exceeding that of the metal-based material.

There are many examples of producing hydrogenated fullerenes using expensive noble metal catalysts such as Ru and Rh, but very few examples use inexpensive Ni. The only example is the hydrogenation of fullerene using a Ni / diatomaceous earth catalyst prepared by Shigematsu et al. Supporting nickel on diatomaceous earth (K. Shi.
gematsu et al. , ChemistryE
xpress, 8 , p483-486 (1993)).
However, the number of hydrogen added under severe conditions of 100 atm and 180 ° C. is about 30 (C ₆₀ H ₃₀ , m / z
750). Also, the recovery of hydrogenated fullerene per 500 mg of the starting material was at most 167 mg, and the recovery was very poor (about 33%). This is considered to be because the diatomaceous earth used as a carrier considerably adsorbed C ₆₀ fullerene as a starting material and hydrogenated fullerene as a product.

[0005]

Under these circumstances, the present inventors focused on fullerene as a carbon material in view of the above-mentioned prior art, and conducted hydrogenation of fullerene under mild conditions and hydrogenation of the fullerene under mild conditions. As a result of intensive research aimed at establishing a new fullerene conversion method that can efficiently and selectively recover hydrogen from hydrogenated fullerenes and developing excellent hydrogen storage materials, nickel was converted to activated alumina. It has been found that the initial object can be achieved by using the impregnated and supported Ni / Al ₂ O ₃ catalyst, and the present invention has been completed.

[0006]

[MEANS FOR SOLVING THE PROBLEMS]
The present invention comprises the following technical means. (1) Ni / A in which nickel is supported on activated alumina
l_Two O_Three By using a catalyst, C₆₀Fullerene in water
To hydrogenated fullerene or hydrogenated fullerene to C₆₀ Fuller
Fullerene conversion method characterized by converting to fullerene
Law. (2) Ni / A in which activated alumina is impregnated and supported on nickel
l_Two O_Three Utilizing the conversion reaction of fullerene by a catalyst,
High efficiency and high selectivity under mild hydrogenation conditions₆₀H
Laren C₆₀H₃₆Hydrogenation characterized by conversion to
Fullerene manufacturing method. (3) Hydrogen is converted to C using the conversion reaction described in (1) above.₆₀
Hydrogenation into fullerene and hydrogenation Fullerene C₆₀H₃₆To
A method for producing a hydrogen storage material, comprising converting the hydrogen storage material. (4) Ni / A in which activated alumina is impregnated and supported on nickel
l_Two O_ThreeUtilizing the conversion reaction of fullerene by a catalyst,
Hydrogenated fullerene C₆₀H₃₆Dehydrogenation reaction and hydrogenation
Fullerene C₆₀H₃₆To C₆₀Convert to fullerene and hydrogen
How to recover.

[0007]

Next, the present invention will be described in more detail. As described above, the present invention efficiently stores hydrogen (hydrogen storage rate: 4.8 wt%) by converting C ₆₀ fullerene as a carbon material into hydrogenated fullerene, and can easily perform hydrogen storage from the hydrogen storage material. It is characterized in that hydrogen is efficiently recovered by the method. The present inventors have focused on fullerene as a carbon material, very specific materials having at C ₆₀ fullerene spherical molecule composed of 60 carbon atoms was attempted hydrogen storage to it, the unsaturated bonds 30 in the molecule It is. Since the simple method of fullerene extraction from soot was reported by Kretschmer et al. In 1990, the cost has been decreasing year by year.

The present inventors have prepared a supported nickel catalyst using activated alumina, which would hardly adsorb fullerene and hydrogenated fullerene, as a carrier, and hydrogenated fullerene (C ₆₀ → C ₆₀₎ under mild conditions. H ₃₆ ) and the recovery of hydrogen from hydrogenated fullerene (C ₆₀ H ₃₆ → C ₆₀ ).
As a result, 50 atm / 100 ° C or 25 atm / 15
Even under mild conditions such as 0 ° C, high efficiency (about 100
It was prepared C ₆₀ H ₃₆ from C ₆₀ fullerene%) and high selectivity (about 100%). Further, when the produced hydrogenated fullerene was heated and stirred at 150 ° C. under an inert gas atmosphere such as helium under the above-mentioned catalyst, hydrogen was recovered, and C ₆₀ fullerene was not decomposed. Collected.

In the present invention, nickel is used as activated aluminum.
Ni / Al supported by impregnation_Two O_Three The catalyst is nickel nitrate
Activated alumina is impregnated in the aqueous solution, and the water is slowly evaporated.
After emitting, dry in a dryer overnight, then at 500 ℃
NiO / Al after firing for 3 hours_Two O_Three Was prepared. Carry amount
Is 10% by weight of Ni. 5 under hydrogen atmosphere before reaction
Reduction treatment at 00 ° C for 3 hours, Ni / Al_TwoO_ThreeMake
Was. In the above method, hydrogenation conditions include hydrogen pressure
Is 25-75 atm, the reaction temperature is 100-250 ° C,
Illustrative is agitation for 24 hours. This results in an efficiency of about 10
0%, selectivity about 100%, C₆₀Fullerene to C₆₀H
₃₆Can be converted to Further, in the above method,
The conditions for the dehydrogenation reaction are as follows:
Heated to reflux for 3 days. This gives C₆₀H
Hydrogen can be recovered without decomposing the ralen
Wear.

Next, carbon as a hydrogen storage material will be described. Hydrogenation to fullerene is about 2300kJ
/ Mol / mol exotherm and progressed relatively easily. On the other hand, hydrogen abstraction from hydrogenated fullerene is a reverse reaction and requires more energy than the opposite. This solid hydrogen compound, which is light and stable in air and has a high storage rate, is more suitable for long-distance transportation and long-term storage than mounting it in places where hydrogen is instantaneously taken out, such as in automobiles and airplanes. Embodiments of the use of the hydrogen storage material of the present invention are as follows. For example, energy obtained in an area rich in natural energy (such as a desert area) is converted into hydrogen and then transported to an energy-intensive area. In the energy-intensive areas, the unloaded hydrogen is unloaded and used for power generation, hydrogen vehicles, and raw materials for the chemical industry. Fullerene can be suitably used for bridging the two. Light and bulky, yet 2 even in an oxygen atmosphere
It is considered to be a very promising hydrogen storage material for long-distance transport if it is not oxidized up to 80 ° C and exists as a solid stably. The hydrogen storage material of the present invention can be used for various purposes.However, the material may be designed after determining what kind of performance material is needed and where, and the range is not particularly limited. .

[0011]

Next, the present invention will be specifically described based on examples.
I will tell. The following examples illustrate preferred examples of the present invention.
The present invention is not limited by the examples.
is not. Example (1) Production of hydrogenated fullerene Fullerene was manufactured by Hoechst C₆₀(Purity about 100%)
Was. The catalyst is activated alumina (Sumitomo Chemical, KHS-46)
10 wt. % Impregnated and used
Was. Stainless steel with inner diameter of 3.9cm and inner volume of 390ml
C in the reaction vessel₆₀ (100 mg) in toluene (200 m
l) is dissolved in a catalyst (Ni / Al_Two O_Three , 2g)
Poured with. Autoclave (high pressure reactor)
After setting the reaction vessel using a torque wrench,
The atmosphere was replaced by bubbling hydrogen (500 ml / min, 15
min). After replacing with hydrogen, set to the specified hydrogen pressure,
After confirming that there was no such problem, the temperature was raised to the target temperature.
The stirrer was rotated at a speed of about 33 times / minute,
Contact was uniform. In this device,
It has a function of bubbling gas-phase hydrogen.
Therefore, hydrogen clogged at the top of the vessel at high pressure
It is guided to the bottom of the container through the ring tube and circulates. reaction
After that, the solvent was removed and the physical properties of the residue were measured by mass (mass spectrometer).
), FT-IR, UV, XRD, TG, DTA, etc.
I checked more.

(2) Recovery of hydrogen from hydrogenated fullerene Further, extraction of hydrogen from hydrogenated fullerene was examined by a reverse reaction using the same catalyst. After producing the hydrogenated fullerene by the procedure of the above (1), the reaction solution was transferred to a three-necked flask together with the catalyst. 15 with Liebig cooling pipe
The mixture was heated under reflux at 0 ° C. for 3 days under a helium atmosphere. After the reaction, the catalyst and the solvent were removed, and the physical properties of the residue were examined with a mass spectrometer.

(3) Results FIG. 1 shows the temperature and the temperature when the hydrogenation reaction was performed at 150 ° C. for 2 hours.
Pressure changes were indicated. Initial hydrogen pressure is 50 kg-f / cm
² The target of 150 ° C. was reached in about one hour.
After reaching, the pressure gradually decreased. After 2 hours, about 6.
A pressure drop of 5 kg-f / cm ² was observed. FIG. 2 shows the visible spectrum before and after the reaction. Although before the reaction is visible absorption due to purple C ₆₀ observed in 450-700 nm, absorption of these after the reaction it is found that considerably weaker. This is probably because the conjugated double bond replaced the CH bond. After removing the solvent with an evaporator, the residue was analyzed with a mass spectrometer. The mass spectrum is shown in FIG. A strong response at m / z 756 was observed. The absence of m / z 720, which indicates the starting material, suggests that C ₆₀ H ₃₆ was produced quite selectively by the hydrogenation reaction. C ₆₀ H ₆₀ (m / z 780), which was assumed to be completely hydrogenated, was not observed.

[0014] FT-IR of the product, UV, results of examining the XRD spectrum, C ₆₀ is 1426.1,1180.
The product shows 2912.9, 2847.4, 1625., while exhibiting IR absorption at 2,573.7, 525.5 cm ^-1 .
7, 1457.0, 1384.6, and 668.2 cm ^-1 . This was consistent with the IR spectrum of C ₆₀ H ₃₆ obtained by Hauffler et al. In a Birch reduction. Also,
C ₆₀ whereas shows the UV absorption at 223,257,329,377Nm, the product showed an absorption only 220 nm.
Since the butadiene type π-π absorption is around here, it is considered that the conjugated double bond property was also lost by hydrogenation. By the way, this UV spectrum is also Ha
consistent with that reported by Ufler et al.
The XRD spectrum also coincided with the pattern of C ₆₀ H ₃₆ of the body-centered cubic lattice (bcc). Above, mass and I
From the results of R, UV and XRD, C ₆₀ H
₃₆ were found to be selectively generated.

From the change in visible absorption (600 nm) in FIG.
₆₀ apparent conversions can be calculated. On the other hand, the apparent yield (φ) was determined from the ratio of product (mg) / reactant (mg). FIG. 4 shows the relationship between the conversion and the yield over time. After several hours, the conversion reached almost 100%. The yield is also close to 100%. The conversion of toluene, a solvent, to methylcyclohexane was determined by gas chromatography. As a result, it was found that the conversion and the pressure decrease increased with time over time. This suggests that the main factor of the pressure decrease is due to hydrogenation of the solvent toluene.

As a result of examining the temperature effect in the hydrogenation reaction, a large number of mass peaks containing the reactant C ₆₀ were observed at 50 and 100 ° C. Particularly at the reaction at 50 ° C., considerable unreacted C ₆₀ was recovered. This may be the result of low activity and low selectivity due to the low temperature reaction. At 150 ° C. or higher, C ₆₀ H ₃₆ was selectively produced as shown in FIG.
By the way, even at 250 ° C., only C ₆₀ H ₃₆ was recognized,
No formation of C ₆₀ H ₆₀ was observed. As a result of examining the relationship between the pressure decrease and the hydrogenation of toluene, it seems that there is also a strong correlation between the two. In addition, the pressure is 25-75k
According to the results obtained when g-f / cm ² was changed, no appropriate pressure effect was observed within this pressure range.

In this embodiment, the temperature (150-250)
℃) ・ Pressure (25-75kg-f / cm ² ) range
Neither the formation of C ₆₀ H ₆₀ nor the decomposition of hydrogenated fullerene was observed. The high selective production of C ₆₀ H ₃₆ are observed, C ₆₀ H ₃₆ is considered to be because structurally most distortion is smaller in the hydrogenation fullerene. The hydrogen storage rate of C ₆₀ H ₃₆ is 4.8 wt. %. This value is much larger than that of the lanthanum-nickel-based metal (1.4 wt.%), And is expected to be used as a hydrogen storage material.

TG-DTA was performed to examine the thermal stability of hydrogenated fullerene in air. FIG. 5 shows the results of TG-DTA of C ₆₀ H ₃₆ in air. 28
Exothermic peaks were observed at 0 ° C and 400 ° C. In the former, the weight increased, and in the latter, the weight decreased. Each C
It believed to be due to partial oxidation and combustion of ₆₀ H _36. Calculation from the molar ratio suggested that C ₆₀ H ₃₆ O _4.8 was produced by partial oxidation. It is unknown at this time whether the partially oxidized compound is present as an epoxide, but if C ₆₀ H ₃₆ has 12 isolated double bonds and if epoxidation occurs, About 1
It is calculated that the double bond of / 3 is epoxidized.

TG in C ₆₀ H ₃₆ helium atmosphere
FIG. 6 shows the results of -DTA. C ₆₀ H under helium
Of course, partial oxidation and combustion of ₃₆ did not occur, but it was found that decomposition of C ₆₀ H ₃₆ started at about 420 ° C. TPD of C ₆₀ H ₃₆ under helium (Temperatur
The result of e-Programmed Degradation also supports the result of TG-DTA. That is, the strained C ₆₀ H ₃₆
Was found to be thermally unstable and self-decompose at around 420 ° C. On the other hand, C ₆₀ does not decompose under helium,
It was also found that sublimation started around 00 ° C.

Hydrogen desorption is also important for hydrogen storage materials. The fullerene hydrogenated with Ni / Al ₂ O ₃ was then dehydrogenated using a reverse reaction. The hydrogenated fullerene solution was transferred together with the catalyst to a three-necked flask equipped with a Liebig condenser, and was placed in a helium atmosphere for 150 days a day.
FIG. 7 shows a mass spectrum after the mixture was heated and refluxed at ℃.
Peak of C ₆₀ H ₃₆ is While much smaller in FIG. 3, it can be seen that the peak of C ₆₀ has emerged greater.
This suggests that the reverse reaction, dehydrogenation, was gradually progressing due to the catalytic reaction.

(4) Usefulness of hydrogenated fullerene C ₆₀ H _{36 as} a hydrogen storage material 5 wt. % -Rh / Al ₂ O ₃ hydrogenated fullerenes with a (FIG. 8), and dehydrogenation using the reverse reaction. The hydrogenated fullerene solution was transferred together with the catalyst to a three-necked flask equipped with a Liebig condenser, and heated and refluxed at 150 ° C. for 3 days under a helium stream.
Shown in It can be seen that the peaks of C ₆₀ H ₃₆ and C ₆₀ H ₁₈ are considerably smaller while the peaks of C ₆₀ are larger. This suggests that the dehydrogenation reaction gradually progressed on the Rh catalyst. Further, the same hydrogenated fullerene was used as a dichlorodicyanobenzoquinone (DDQ, m / z 227).
FIG. 10 shows a mass spectrum when the reaction (heating under reflux) was performed at 0 ° C. for 30 minutes. The peaks of C ₆₀ H ₃₆ and C ₆₀ H 18 almost disappeared, and the recovery of C ₆₀ as a raw material was observed.
On the other hand, dichlorodicyanobenzoquinone receives two hydrogens and receives dichlorodicyanodihydrobenzene (DH
B, m / z 229). That is, by using dichlorodicyanobenzoquinone as mediators, suggesting that can facilitate the extraction of hydrogen from C _60. These results indicate that the hydrogenated fullerene is useful as a hydrogen storage material.

[0022]

As described above in detail, the present invention utilizes a fullerene conversion reaction by a Ni / Al ₂ O ₃ catalyst in which nickel is impregnated and supported on activated alumina, thereby achieving high efficiency under mild hydrogenation conditions. High selectivity with C ₆₀ fullerene
₆₀ H ₃₆ preparation of hydrogenated fullerene and converting to a method for producing a hydrogen storage material, characterized by converting hydrogen and hydrogen was introduced into the C ₆₀ fullerene hydride fullerene C ₆₀ H _36, A dehydrogenation reaction of hydrogenated fullerene C ₆₀ H ₃₆ is performed by utilizing a conversion reaction of fullerene by a Ni / Al ₂ O ₃ catalyst in which nickel is impregnated and supported on activated alumina, and hydrogenated fullerene C ₆₀ H ₃₆ is converted to C ₆₀ fullerene. The present invention relates to a method for converting and recovering hydrogen. According to the present invention, 1) a hydrogenated fullerene useful as a hydrogen storage material can be produced with high efficiency and high selectivity. 2)
Hydrogen can be efficiently recovered from the hydrogenated fullerene. 3) A method for converting fullerene can be provided. 4) An excellent hydrogen storage material having high hydrogen storage can be provided. Special effects such as the ability to provide storage and utilization techniques can be achieved.

[Brief description of the drawings]

FIG. 1 shows changes in temperature and pressure when a hydrogenation reaction is performed at 150 ° C.

FIG. 2 shows the visible spectrum before and after the reaction.

FIG. 3 shows a mass spectrum.

FIG. 4 shows the relationship between conversion and yield over time.

FIG. 5 shows the results of TG-DTA.

FIG. 6 shows a result of TG-DTA in a helium atmosphere.

FIG. 7 shows a mass spectrum of dehydrogenated fullerene by Ni / Al ₂ O ₃ .

FIG. 8 shows a mass spectrum of hydrogenated fullerene.

FIG. 9 shows a mass spectrum after heating and refluxing the hydrogenated fullerene.

FIG. 10 shows a mass spectrum obtained by dehydrogenation with DDQ.

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[Procedure amendment]

[Submission date] March 1, 2000 (200.3.1)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claims

[Correction method] Change

[Correction contents]

[Claims]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0006

[Correction method] Change

[Correction contents]

[0006]

The present invention for solving the above-mentioned problems comprises the following technical means. (1) Ni / A in which nickel is supported on activated alumina
By using l ₂ O ₃ catalyst, the conversion method of fullerene and converting the C ₆₀ fullerene or hydrogenation fullerene hydride fullerene C ₆₀ fullerene. (2) Ni / A in which activated alumina is impregnated and supported on nickel
Utilizing the conversion reaction of fullerene by l ₂ O ₃ catalyst ,
Preparation of hydrogenated fullerene and converting the C ₆₀ fullerene C ₆₀ H _36. (3) Hydrogen is converted to C ₆₀ using the conversion reaction described in (1) above.
A method for producing a hydrogen storage material, comprising introducing hydrogen into fullerene to convert hydrogen into hydrogenated fullerene C ₆₀ H ₃₆ . (4) Ni / A in which activated alumina is impregnated and supported on nickel
Utilizing the conversion reaction of fullerene by l ₂ O ₃ catalyst,
How do dehydrogenation of hydrogenated fullerene C ₆₀ H _36, to convert the hydrogenated fullerene C ₆₀ H ₃₆ to C ₆₀ fullerene and hydrogen, it is recovered.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) // C07B 61/00 300 B01J 23/74 321M 321Z F term (Reference) 4G040 AA42 4G046 CA02 CB08 4G069 AA03 BA01A BA01B BB02A BB02B BC68A BC68B CB02 CB07 DA08 FB14 4H006 AA02 AC11 BA09 BA21 BA30 BA55 BE20 4H039 CA40 CB10

Claims (4)

[Claims] 1. Use of a Ni / Al ₂ O ₃ catalyst in which nickel is impregnated and supported on activated alumina to convert C ₆₀ fullerene to hydrogenated fullerene or hydrogenated fullerene to C
_A method for converting fullerenes, which comprises converting to ₆₀ fullerenes. _2. A method for converting C ₆₀ fullerene into C ₆₀ H with high efficiency and high selectivity under mild hydrogenation conditions by utilizing the conversion reaction of fullerene by a Ni / Al ₂ O ₃ catalyst in which nickel is impregnated on activated alumina. _A method for producing hydrogenated fullerene, which is converted to ₃₆ . 3. The conversion reaction according to claim 1, wherein hydrogen is introduced into C ₆₀ fullerene and hydrogen is converted into hydrogenated fullerene C _60.
Method for producing a hydrogen storage material, characterized by converting the H _36. 4. Utilizing the conversion reaction of the fullerene by Ni / Al ₂ O ₃ catalyst impregnated supported on activated alumina nickel performs dehydrogenation of hydrogenated fullerene C ₆₀ H _36, hydrogenated fullerene C ₆₀ H converts the ₃₆ to C ₆₀ fullerene and hydrogen, a method of recovering.