JP5220534B2 - Solid base catalyst, method for producing the same, and method for using the same - Google Patents

Description

  The present invention relates to a solid base catalyst, a method for producing the same, and a method using the same, and more particularly to a solid base catalyst obtained by doping a carbon material with nitrogen.

Examples of the reaction catalyzed by a base include a transesterification reaction used for the synthesis of biodiesel fuel and a Knoevenagel reaction which is one of carbon-carbon bond forming reactions. Conventionally, homogeneous catalysts such as alkali hydroxides and amines have been mainly used as base catalysts in these reactions (for example, Patent Document 1).
JP 2007-077347 A

  However, when a homogeneous catalyst is used, for example, it is difficult to separate the catalyst from the product, and there is a problem that contamination of the product occurs.

  In contrast, a heterogeneous catalyst (that is, a solid base catalyst) has an advantage that the catalyst can be easily separated from the product, the product does not contaminate, and the catalyst can be recycled. is there. However, at present, the development of solid base catalysts is not sufficiently advanced.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an unprecedented excellent solid base catalyst, a method for producing the same, and a method for using the same.

  A method according to an embodiment of the present invention for solving the above-described problem is characterized by using a carbon material doped with nitrogen as a solid base catalyst in a chemical reaction. ADVANTAGE OF THE INVENTION According to this invention, the method of using the solid base catalyst which was excellent in the conventional in the chemical reaction catalyzed by a base can be provided.

  In the method, the chemical reaction may be a carbon-carbon bond forming reaction. Furthermore, the carbon-carbon bond forming reaction may be a Kunafenergel reaction or an aldol reaction. Further, the chemical reaction may be a transesterification reaction. In these cases, a carbon-carbon bond forming reaction important in the synthesis of pharmaceuticals and the like and a transesterification reaction important in the synthesis of biodiesel fuel can be effectively performed to obtain a high conversion rate and yield.

  A method for producing a solid base catalyst according to an embodiment of the present invention for solving the above problems includes a heating step of heating a carbon material to increase its temperature, and holding the carbon material at a predetermined increased temperature. A holding step, and a cooling step for cooling the carbon material to lower its temperature, and contacting ammonia gas with the carbon material in the temperature raising step and the holding step, and further in the cooling step The method further comprises contacting the carbon material with ammonia gas to produce a solid base catalyst in which the carbon material is doped with nitrogen. ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the outstanding solid base catalyst which has not existed conventionally can be provided.

  Moreover, in the said manufacturing method, the said predetermined temperature in the said holding process is in the range of 400 degreeC-800 degreeC, and in the said cooling process, until the temperature of the said carbon material falls in the range of 150 degreeC-350 degreeC. During this period, ammonia gas may be brought into contact with the carbon material, and thereafter contact of ammonia gas with the carbon material may be stopped. Moreover, in the said manufacturing method, it is good also as making the said carbon material contact air with ammonia gas. In these cases, a solid base catalyst having particularly high activity can be produced.

  A solid base catalyst according to an embodiment of the present invention for solving the above problems is characterized by being produced by any one of the production methods described above. According to the present invention, an unprecedented excellent solid base catalyst can be provided.

  Further, in any one of the above methods in which a nitrogen-doped carbon material is used as a solid base catalyst in a chemical reaction, the nitrogen-doped carbon material is the solid base catalyst produced by any one of the above production methods. It may be there. In this case, it is possible to provide a method of using an unprecedented excellent solid base catalyst in a chemical reaction catalyzed by a base.

  Below, the solid base catalyst which concerns on one Embodiment of this invention, its manufacturing method, and the method of using this are demonstrated. Note that the present invention is not limited to the present embodiment.

  The solid base catalyst according to the present embodiment (hereinafter referred to as “the present catalyst”) is a heterogeneous carbon catalyst made of a carbon material doped with nitrogen. The carbon material is not particularly limited as long as it can be doped with nitrogen. For example, carbon black such as ketjen black, activated carbon, and carbon fiber can be used. Further, as the carbon material, a carbon material having a special shell-like structure on the order of nanometers (hereinafter referred to as “nanoshell carbon catalyst”) can also be used.

  The nanoshell carbon catalyst is, for example, a compound (for example, an iron complex) containing a transition metal other than a noble metal in a precursor of a thermosetting resin (for example, polyfurfuryl alcohol or phenol resin) (for example, furfuryl alcohol as a monomer). And a cobalt complex) and a nitrogen-containing compound (for example, melamine or phthalocyanine), and the mixture is polymerized by heat treatment to produce the thermosetting resin containing the transition metal-containing compound and the nitrogen-containing compound. It can be obtained by producing and further carbonizing the thermosetting resin by heat treatment.

  This nanoshell carbon catalyst has a nanoshell structure including a hollow shell formed of graphene and having a diameter of about 10 nm. This nanoshell structure is formed by the catalytic action of fine metal particles generated by pyrolysis in the carbonization step by adding a transition metal-containing compound in advance when carbonizing an organic substance as described above.

  And this nanoshell carbon catalyst itself has a basic catalyst activity, for example, even if it does not use a platinum catalyst together, The base catalyst activity improves further especially by incorporating a nitrogen atom or a boron atom.

  Since this catalyst is a heterogeneous catalyst, it can be easily separated from the product, does not cause contamination to the product, and can be recycled. Further, the present catalyst can maintain its basic catalytic activity even at a high temperature of about 400 ° C. by using the nitrogen-doped carbon material itself as the catalyst body, and can also be produced at a relatively low cost.

  The method using a solid base catalyst according to this embodiment (hereinafter referred to as “the present usage method”) is a method of using a carbon material doped with nitrogen as a solid base catalyst in a chemical reaction. That is, in this method of use, the above-described catalyst can be used as a carbon material doped with nitrogen.

  The chemical reaction in this method of use is not particularly limited as long as it is catalyzed by a base and promotes the reaction. For example, it can be a carbon-carbon bond forming reaction or a transesterification reaction.

  Here, formation of a carbon-carbon bond is an important reaction for forming a molecular skeleton in fine chemistry for synthesizing pharmaceuticals and basic chemicals, for example. The transesterification reaction is an important reaction used for synthesizing, for example, biodiesel fuel.

  When the chemical reaction in this method of use is a carbon-carbon bond formation reaction, the carbon-carbon bond formation reaction is, for example, a Kunafener gel reaction (Kunafenergel condensation), an aldol reaction, a Michael reaction ( Michael addition).

  Specifically, in the present method of use, when the present catalyst is used as a solid base catalyst in the Kunafener gel reaction, for example, in the presence of the present catalyst, an active methylene compound and an aldehyde or ketone are heated to a predetermined temperature. Then, the alkene can be obtained as a product by reaction (dehydration condensation) for a predetermined time.

  Further, in this method of use, when the present catalyst is used as a solid base catalyst in a transesterification reaction, for example, in the presence of the present catalyst, fats and oils (triglycerides) such as vegetable fats and oils and lower alcohols such as methanol are used. By reacting at a predetermined temperature for a predetermined time, a fatty acid methyl ester usable as a biodiesel fuel can be obtained as a product.

  The method for producing a solid base catalyst according to the present embodiment (hereinafter referred to as “the present production method”) is a method for producing a solid base catalyst in which a carbon material is doped with nitrogen, and the above-described catalyst is produced. One of the methods.

  The present manufacturing method includes a heating step for heating a carbon material to increase its temperature, a holding step for holding the carbon material at a predetermined elevated temperature (hereinafter referred to as “holding temperature”), and the carbon material. And cooling the temperature to lower its temperature. These steps can be performed, for example, by installing a predetermined reaction vessel holding the carbon material as described above in an electric furnace, and heating and cooling the carbon material in the electric furnace.

  In the temperature raising step, the carbon material is heated at a predetermined temperature raising rate until the temperature reaches the holding temperature. In the holding step, the holding temperature for holding the heated carbon material is not particularly limited as long as it is a preferable temperature for doping the carbon material with nitrogen. For example, the holding temperature may be within a range of 400 ° C to 800 ° C. Preferably, it can be in the range of 500 ° C to 800 ° C, more preferably in the range of 500 ° C to 700 ° C, and particularly preferably in the range of 550 ° C to 650 ° C. it can.

  In addition, the time for holding the carbon material at the holding temperature in the holding step (hereinafter referred to as “holding time”) is not particularly limited as long as it is a preferable time for doping the carbon material with nitrogen. .5 hours to 10 hours, preferably 0.5 hours to 8 hours, more preferably 0.5 hours to 3 hours. it can.

  And in this manufacturing method, while making ammonia gas contact with a carbon material in a temperature rising process and a holding process, and also making ammonia gas contact with the carbon material also in a cooling process, the carbon material is doped with nitrogen. A solid base catalyst is produced. That is, the ammoxidation method in which the carbon material is brought into contact with ammonia gas and nitrogen is doped into the carbon material is also performed in the cooling step in addition to the temperature raising step and the holding step.

  The contact between the carbon material and the ammonia gas can be performed, for example, by circulating ammonia gas through a reactor holding the carbon material in an electric furnace. That is, in this case, not only while the temperature of the carbon material is raised by heating (temperature raising step) and while the carbon material is held at the holding temperature (holding step), but further after cooling, the carbon material While the temperature of the carbon material is decreasing (cooling step), ammonia gas is continuously circulated.

  In this way, in the cooling step, by bringing ammonia gas into contact with the carbon material that is being cooled, the temperature of which is lower than the holding temperature, nitrogen is effectively introduced into the carbon material. High solid base catalyst.

  The period in which the carbon material and ammonia gas are brought into contact in the cooling step is not particularly limited. For example, when the holding temperature in the holding step is within a range of 400 ° C. to 800 ° C., in the cooling step, the carbon material Until the temperature falls within the range of 150 ° C. to 350 ° C., ammonia gas can be brought into contact with the carbon material, and then contact of the ammonia gas with the carbon material can be stopped. That is, in the cooling step, when the temperature of the carbon material decreases from the holding temperature to a range of 150 ° C. to 350 ° C., the contact of the ammonia gas with the carbon material is stopped.

  In this case, the contact between the carbon material and the ammonia gas may be stopped, and the gas to be brought into contact with the carbon material may be switched from ammonia gas to a gas not containing ammonia gas. That is, for example, the contact of ammonia gas with respect to the carbon material is stopped, and at the same time, the contact of gas not containing ammonia gas with respect to the carbon material is started. As the gas not containing ammonia gas, for example, nitrogen or air can be used.

  Further, air can be brought into contact with the carbon material together with ammonia gas. That is, in this case, for example, a mixed gas containing ammonia gas and air in a predetermined ratio is used. This ratio can be appropriately determined according to the processing conditions such as the type of carbon material, the holding temperature, and the holding time. For example, the concentration (volume) of ammonia gas in a mixed gas obtained by mixing ammonia gas and air. %) Can be in the range of 60% to 95%, preferably in the range of 70 to 90%, more preferably in the range of 80 to 90%. By using air in addition to ammonia gas, a more active solid base catalyst can be produced.

  The contact between the ammonia gas and air and the carbon material can be performed in all or some of the temperature raising step, the holding step, and the cooling step. That is, for example, a mixed gas containing ammonia gas and air can be used through the temperature raising step, the holding step, and the cooling step.

  Further, in this case, for example, a mixed gas is used from the temperature raising step to the middle of the cooling step (for example, until the temperature of the carbon material is lowered to a predetermined temperature as described above), and then the mixed gas is converted to ammonia. It is also possible to switch to a gas that does not contain a gas (for example, nitrogen or air). Further, a mixed gas can be used in the temperature raising step, and then ammonia gas can be used from the holding step.

  As described above, in this production method, in what process (for example, the type of carbon material, the holding temperature, the holding time, the concentration of ammonia or air in the gas to be circulated) the carbon material is processed under the conditions. The activity of the solid base catalyst finally obtained can be controlled by the history of conditions.

  Next, specific examples will be described.

[Example 1]
Catalysts were prepared under different treatment conditions by the ammoxidation method, and the performance of the prepared catalysts as solid base catalysts was evaluated.

  First, a catalyst was prepared using a commercially available ketjen black or activated carbon (for column pack, GL Science Co., Ltd.) as a carbon material. In a quartz tube having an outer diameter of 15 mm and an inner diameter of 13 mm, 150 mg of a carbon material was fixed with quartz wool, and the quartz tube was placed in an electric furnace. The electric furnace is closed and a mixed gas obtained by mixing ammonia and compressed air at a predetermined ratio (volume%) is circulated at a total flow rate of 100 mL / min, and the carbon material is heated and held at a predetermined processing temperature for a predetermined time. did. Then, the electric furnace was opened and air-cooled. The carbon material was taken out, weighed, and stored in a sample bottle.

  In FIG. 1, each processing condition and a yield are shown correspondingly. In the left column of FIG. 1, the content of each processing condition is described in the order of “type of carbon material−processing temperature−processing ammonia concentration−processing time”. Here, “KB” indicates that ketjen black is used as the carbon material, and “AC” indicates that activated carbon is used as the carbon material.

  Specifically, for example, the third treatment condition “KB-600 ° C.-90% -1h” from the top of FIG. 1 is a mixed gas (ammonia containing ketjen black at 600 ° C. and 90% ammonia. 90%, air 10%), and kept for 1 hour.

  In the right column of FIG. 1, the yield (mg) of the carbon material is shown. That is, for example, the third from the top in FIG. 1 shows that the yield when the carbon material was treated under the treatment condition “KB-600 ° C.-90% -1 h” was 148 mg. The decrease in yield means that part of the carbon material burned and disappeared by the heat treatment.

  As shown in FIG. 1, the high yield was obtained even after processing at a high temperature of 400 ° C. or higher, and the advantage of the carbon material that it could be used at a high temperature was confirmed. However, the lower the ammonia concentration, that is, the higher the air concentration, the lower the yield due to the combustion of the carbon material.

  Next, Kunafener gel reaction was performed using the catalyst prepared as described above as a solid base catalyst. 100 mg of catalyst, 9.9 mmol of benzaldehyde, 9.4 mmol of ethyl cyanoacetate, and 4 ml of 1-butanol were weighed and put into a Teflon (registered trademark) inner cylindrical sealed container (reactor) containing a magnetic stirrer. . The reactor was allowed to stand in a warm water bath at 80 ° C. for 20 minutes and then stirred for 1 hour. After the reaction, the reactor was removed from the hot water bath and cooled with cold water. The reaction solution and the catalyst were separated by suction filtration.

  To the separated reaction solution, 1 ml of toluene was added as an internal standard, diluted to 25 ml with 1-butanol, quantified by gas chromatography (GC), and qualitatively analyzed by a gas chromatograph mass spectrometer (GC-MS). The yield of ethyl cyanocinnamate, which is a product in the Kunafenergel reaction, was determined on the basis of ethyl cyanoacetate.

  In FIG. 2, the treatment temperature in the preparation of the catalyst and the conversion rate and yield in the Kunafenergel reaction are shown in correspondence. That is, FIG. 2 shows each treatment condition in the preparation of the catalyst described in the same manner as in FIG. 1, and benzaldehyde (when the catalyst prepared in each treatment condition is used as a solid base catalyst in the Knefenergel reaction) The conversion rate of BA), the conversion rate of ethyl cyanoacetate (ECA), and the yield of the product ethyl cyanocinnamate (ECC) are shown in correspondence.

  Specifically, for example, in the fourth from the top in FIG. 2, as a result of using a catalyst prepared under the treatment condition “KB-600 ° C.-90% -1 h”, the conversion of benzaldehyde is 28.2%. The conversion of ethyl cyanoacetate was 26.1%, and the yield of ethyl cyanocinnamate was 27.0%.

  Further, for example, the third from the bottom in FIG. 2 shows that the conversion of benzaldehyde was 48.3% as a result of using a catalyst prepared under the treatment condition “AC-600 ° C.-90% -1h”. The conversion of ethyl acetate was 48.9%, and the yield of ethyl cyanocinnamate was shown to be 49.6%.

  The conversion rate (%) was calculated as a percentage of the amount consumed by the reaction relative to the amount used for the reaction (9.9 mmol for benzaldehyde).

  Further, the yield (%) was calculated as a value representing the ratio of the actually obtained amount to the theoretically obtainable amount as a percentage.

  In FIG. 3, similarly to FIG. 2, when Ketjen Black is used as the carbon material, the treatment time in the preparation of the catalyst and the conversion rate and yield in the Kunafenergel reaction are shown in correspondence with each other. Further, in FIG. 4, similarly to FIG. 3, the ammonia concentration in the mixed gas circulated as the processing gas in the preparation of the catalyst is shown in correspondence with the conversion rate and yield in the Kunafenergel reaction. For comparison, the yield was 5.3% when a similar Knafenergel reaction was performed without using a catalyst (that is, without catalyst).

  As shown in FIG. 2 to FIG. 4, when a catalyst made of a carbon material doped with nitrogen by an ammoxidation method is used as a solid base catalyst, the conversion rate and yield in the Kunafenergel reaction can be reduced. It was possible to increase significantly compared to. That is, it was confirmed that the carbon material doped with nitrogen as described above exhibits sufficient activity as a solid base catalyst in the Kunafenergel reaction.

  In addition, when activated carbon was used as the carbon material, a solid base catalyst having higher activity was obtained compared to the case where ketjen black was used. In addition, since the aldol reaction also occurred in the process of the Kunefenergel reaction, it was confirmed that the carbon material doped with nitrogen as described above exhibits sufficient activity as a solid base catalyst in the aldol reaction. .

  Further, as shown in FIG. 2, for example, by setting the treatment temperature to around 600 ° C., a solid base catalyst having particularly high activity was obtained. Further, as shown in FIG. 3, the influence of the treatment time on the activity of the solid base catalyst was relatively small. Moreover, as shown in FIG. 4, the solid base catalyst with especially high activity was obtained by making ammonia concentration into the range of 70%-90%. However, as described above, the yield of the carbon material at the time of catalyst preparation tended to decrease due to a decrease in ammonia concentration, that is, an increase in air concentration.

  Next, a transesterification reaction was performed using the catalyst as a solid base catalyst. 100 mg of a catalyst, 10 mmol of ethyl acetate, and 200 mmol of methanol were weighed and put into a Teflon (registered trademark) inner cylindrical sealed container (reactor) having a volume of 100 mL containing a magnetic stirrer. The reactor was allowed to stand in an oil bath at 140 ° C. for 25 minutes and then stirred for 4 hours. After the reaction, the reactor was removed from the oil bath and cooled with cold water. 1 ml of toluene was placed in the reactor as an internal standard, diluted to 25 ml with methanol, and filtered. The filtrate was collected, quantified by GC, and qualitatively analyzed by GC-MS.

  FIG. 5 shows the treatment temperature in the preparation of the catalyst and the yield in the transesterification reaction in correspondence with each other. That is, FIG. 5 shows each treatment condition in the preparation of the catalyst described in the same manner as in FIG. 1, and ethyl acetate (EA) when the catalyst prepared in each treatment condition is used as a solid base catalyst for the transesterification reaction. , The yield of methyl acetate (MA), one of the products, and the yield of ethanol (EtOH), one of the products, are shown in correspondence.

  Specifically, for example, in the third from the top in FIG. 5, as a result of using a catalyst prepared under the treatment condition “KB-600 ° C.-90% -1 h”, the conversion rate of ethyl acetate was 28.8%. The yield of methyl acetate was 32.6% and the yield of ethanol was 31.4%. In addition, the yield of methyl acetate when performing the same transesterification reaction without a catalyst was 10.6%.

  As shown in FIG. 5, by using a catalyst made of a carbon material doped with nitrogen by an ammoxidation method as a solid base catalyst, the conversion rate and yield in the transesterification reaction are greatly increased compared to the case of no catalyst. It was possible to increase. That is, it was confirmed that the carbon material doped with nitrogen as described above exhibits sufficient activity as a solid base catalyst in the transesterification reaction.

[Example 2]
By the ammoxidation method, five types of catalysts were prepared under different treatment conditions in the absence of air, and the performance of the prepared catalysts as a solid base catalyst in the Kunafener gel reaction was evaluated. Ketjen black was used as the carbon material.

  In a quartz tube having an outer diameter of 15 mm and an inner diameter of 13 mm, 150 mg of a carbon material was fixed with quartz wool, and the quartz tube was placed in an electric furnace. The electric furnace was closed, the processing gas was allowed to flow at a flow rate of 100 mL / min, and the carbon material was heated. By this heating, the temperature of the carbon material was increased from room temperature to 500 ° C. at a temperature increase rate of 10 ° C./min, and further increased from 500 ° C. to 600 ° C. at a temperature increase rate of 5 ° C./min. Process). And the carbon material was hold | maintained at 600 degreeC for 1 hour (holding process). Then, the carbon material was cooled and the temperature was lowered (cooling step).

  In Example 2, the carbon material was processed according to five types of schedules I to V as shown in FIG. In FIG. 6, the horizontal axis indicates the time (processing time) (minutes) after the start of heating, and the vertical axis indicates the temperature (° C.) of the carbon material at each processing time.

As shown in FIG. 6, the heating time was from 0 (zero) minutes to 70 minutes, the holding step was from 70 minutes to 130 minutes, and the cooling step was from 130 minutes. Further, in FIG. 6, for each of the five types of schedules I to V, a period in which ammonia (NH ₃ ) is circulated and a period in which nitrogen (N ₂ ) is circulated are indicated by double-headed arrows, respectively. .

  That is, in the first schedule (schedule I), nitrogen (100% nitrogen) was circulated through all steps of the temperature raising step, the holding step, and the cooling step.

  In the second schedule (schedule II), ammonia (ammonia 100%) was circulated through the temperature raising step and the holding step, and then nitrogen was circulated through the cooling step. That is, simultaneously with the start of the cooling process (that is, at the timing when the temperature starts to decrease from 600 ° C.), the gas to be circulated was switched from ammonia to nitrogen, and then nitrogen was circulated.

  In the third schedule (schedule III) and the fourth schedule (schedule IV), ammonia is circulated through the temperature raising process and the holding process until the middle of the cooling process, and then nitrogen is circulated in the latter half of the cooling process. It was. That is, in the schedule III, ammonia is continuously circulated until the temperature falls to 300 ° C. in the cooling process, and when the temperature reaches 300 ° C., the gas to be circulated is switched from ammonia to nitrogen. Circulated.

  In Schedule IV, ammonia is continuously circulated until the temperature drops to 100 ° C. in the cooling process, and when the temperature reaches 100 ° C., the gas to be circulated is switched from ammonia to nitrogen, and then the nitrogen is changed. Circulated.

  In the fifth schedule (schedule V), ammonia was circulated through all the steps of the temperature raising step, the holding step, and the cooling step. That is, in the cooling process, ammonia was circulated until the temperature dropped to around room temperature.

  Then, the electric furnace was opened and air-cooled. And the carbon material was taken out at the temperature of 80 degrees C or less, and was preserve | saved in the sample bottle. In this way, five types of catalysts prepared with different treatment schedules I to V were obtained. Then, the Kunefener gel reaction using each of the five types of catalysts thus prepared as a solid base catalyst was carried out in the same manner as in Example 1 described above.

  FIG. 7 shows each treatment schedule in correspondence with the yield in the Kunafenergel reaction. That is, FIG. 7 shows the yield of each product schedule and ethyl cyanocinnamate (ECC), which is a product when the catalyst prepared in each process schedule is used as a solid base catalyst for the Kunafenergel reaction. The rate is shown correspondingly.

  From the results shown in FIG. 7, the yields when using the catalysts obtained according to schedules II to V using ammonia as the treatment gas were higher than those obtained according to schedule I using only nitrogen.

  In addition, in the case of using the catalyst obtained according to schedules III to V in which ammonia was circulated not only in the temperature raising step and the holding step, but also in the yield step, ammonia was circulated only in the temperature raising step and the holding step. Higher than the catalyst obtained according to Schedule II. Further, the longer the time during which ammonia was circulated in the cooling step, the higher the yield was obtained.

  In addition, similar to the above schedule II, the catalyst is used for the same Knafenergel reaction prepared by a schedule in which ammonia is circulated through the temperature raising process and the holding process and then air (100% air) is circulated through the cooling process. The yield was 13.5%, which was equivalent to the results of Schedule II and Schedule III shown in FIG.

  In addition, the schedule II is modified, and a mixed gas of ammonia and compressed air (ammonia 90%, air 10%) is circulated in the temperature raising process until reaching 600 ° C. (ammonia flow rate 90 mL / min, air flow rate) 10 mL / min), and then in the holding step, ammonia (100% ammonia) was circulated, and then the catalyst was used for the same Knafenergel reaction, prepared according to a schedule in which nitrogen (100% nitrogen) was circulated through the cooling step. The yield was 21.7%, an increase over that for Schedule II shown in FIG.

  Thus, a catalyst with higher activity could be prepared by pretreating the carbon material with air in the temperature raising step. That is, by using air as part of the processing gas in the preparation of the catalyst, an increase in catalytic activity was obtained that only increased the yield of the Kunefener gel reaction.

[Example 3]
In the presence of air, three types of catalysts were prepared under different treatment conditions by an ammoxidation method, and the performance of the prepared catalysts as a solid base catalyst in the Knefenergel reaction was evaluated. Ketjen black was used as the carbon material.

  In a quartz tube having an outer diameter of 15 mm and an inner diameter of 13 mm, 150 mg of a carbon material was fixed with quartz wool, and the quartz tube was placed in an electric furnace. The electric furnace is closed and a mixed gas of ammonia and compressed air (ammonia 90%, air 10%) is circulated at a total flow rate of 100 mL / min (ammonia flow rate 90 mL / min, air flow rate 10 mL / min), and the carbon material is heated. did. By this heating, the temperature of the carbon material was increased from room temperature to 500 ° C. at a temperature increase rate of 10 ° C./min, and further increased from 500 ° C. to 600 ° C. at a temperature increase rate of 5 ° C./min. Process). And the carbon material was hold | maintained at 600 degreeC for 1 hour (holding process). Then, the carbon material was cooled and the temperature was lowered (cooling step).

  In Example 3, the carbon material was treated according to three types of schedules VI to VIII as shown in FIG. In FIG. 8, the horizontal axis indicates the time (processing time) (minutes) after the start of heating, and the vertical axis indicates the temperature (° C.) of the carbon material at each processing time.

As shown in FIG. 8, the heating time was from 0 (zero) minutes to 70 minutes, the holding step was from 70 minutes to 130 minutes, and the cooling step was from 130 minutes. Further, in FIG. 8, for each of the three types of schedules VI to VIII, a period in which a mixed gas (ammonia 90%, air 10%) of ammonia (NH ₃ ) and compressed air (Air) was circulated, and compression A period in which air (air 100%) is circulated is indicated by a double-headed arrow. The switching from the mixed gas to air was performed by stopping the circulation of ammonia and increasing the flow rate of air to a flow rate of 50 mL / min.

  That is, in the sixth schedule (schedule VI), the mixed gas was circulated through the temperature raising process and the holding process, and then the air was circulated through the cooling process. That is, simultaneously with the start of the cooling step (at the timing when the temperature starts to decrease from 600 ° C.), the gas to be circulated was switched from the mixed gas to air, and then the air was circulated.

  In the seventh schedule (schedule VII) and the eighth schedule (schedule VIII), the mixed gas is circulated through the temperature raising process and the holding process to the middle of the cooling process, and then the air is circulated in the latter half of the cooling process. I let you. That is, in the schedule VII, the mixed gas is continuously circulated until the temperature falls to 300 ° C. in the cooling process, and the gas to be circulated is switched from the mixed gas to air at the timing when the temperature reaches 300 ° C. Air was circulated.

  Further, in the schedule VIII, the mixed gas is continuously circulated until the temperature decreases to 100 ° C. in the cooling step, and the gas to be circulated is switched from the mixed gas to air at the timing when the temperature reaches 100 ° C. Air was circulated.

  Then, the electric furnace was opened and air-cooled. And the carbon material was taken out at the temperature of 80 degrees C or less, and was preserve | saved in the sample bottle. Thus, three types of catalysts prepared with different processing schedules VI to VIII were obtained. Then, the Knefenergel reaction using each of the three types of catalysts thus prepared as a solid base catalyst was carried out in the same manner as in Example 1 described above.

  FIG. 9 shows each treatment schedule in correspondence with the yield in the Kunafenergel reaction. That is, FIG. 9 shows the yield of each product schedule and the product ethyl cyanocinnamate (ECC) when the catalyst prepared in each process schedule is used as a solid base catalyst for the Kunafenergel reaction. The rate is shown correspondingly.

  From the results shown in FIG. 9, the yields when using the catalysts obtained according to the schedules VII and VIII in which the mixed gas was circulated not only in the temperature raising step and the holding step but also in the cooling step are both It was higher than the catalyst obtained according to the schedule VI in which the mixed gas was circulated only in the process. Further, the longer the time during which the mixed gas was circulated in the cooling step, the higher the yield was obtained.

  However, when a desorption test by a temperature programmed desorption (TPD) was performed, desorption of ammonia was measured at around 150 ° C. to 300 ° C. for the catalyst obtained according to Schedule VIII. From this, it was considered that the high yield by the catalyst obtained according to the schedule VIII shown in FIG. 9 includes the effect of ammonia adsorbed on the carbon material.

  On the other hand, no desorption phenomenon was observed in the range of at least 150 ° C. to 400 ° C. for the catalyst prepared according to schedule VII in which the mixed gas was switched to air at the time of 300 ° C. in the cooling step.

  Further, when a similar desorption test was performed on the catalyst prepared according to Schedule III in Example 2 described above, no desorption phenomenon was observed in the range of at least 150 ° C to 400 ° C.

[Example 4]
Using a nanoshell carbon catalyst as the carbon material, a catalyst was prepared by an ammoxidation method, and the performance of the prepared catalyst as a solid base catalyst in the Knaevener gel reaction was evaluated.

  The nanoshell carbon catalyst as a carbon material was prepared as follows. That is, first, 3.275 g of a phenol resin (PSK-2320, manufactured by Gunei Chemical Industry Co., Ltd.) was dissolved in 300 mL of acetone. Thereafter, 1.0 g of phthalocyanine iron (manufactured by Tokyo Chemical Industry Co., Ltd.) was added to this solution, and the mixture was subjected to ultrasonic waves for 30 minutes to obtain an amber solution. Next, this amber solution was set in an evaporator and the solvent was removed. Then, it vacuum-dried at 80 degreeC and obtained the iron compound addition phenol.

  Next, carbonization treatment was performed. That is, first, the iron compound-added phenol obtained by the above-described method is put in a quartz tube, purged with nitrogen gas for 20 minutes in an elliptical reflection type infrared gold image furnace, and from room temperature to 900 ° C. over 1.5 hours. The temperature rose. Thereafter, the quartz tube was held at 900 ° C. for 1 hour. Thus, the carbonization process of the iron compound addition phenol was performed.

  Further pulverization was performed. That is, the iron compound-added phenol subjected to carbonization treatment as described above was set together with a 1.5 mm diameter zirconia ball in a planetary ball mill (P-7, manufactured by Fritsch Japan Co., Ltd.). And it grind | pulverized for 90 minutes at the rotational speed of 800 rpm. Thereafter, the pulverized iron compound-added phenol was taken out of the planetary ball mill and passed through a sieve having an aperture of 106 μm. What passed through this sieve was used as a nanoshell carbon catalyst.

  Next, 150 mg of the nanoshell carbon catalyst prepared as described above was fixed with quartz wool in a quartz tube having an outer diameter of 15 mm and an inner diameter of 13 mm, and the quartz tube was placed in an electric furnace. The electric furnace was closed and a mixed gas containing 90% by volume ammonia gas and 10% by volume compressed air was circulated at a total flow rate of 100 mL / min, and the nanoshell carbon catalyst was heated and held at a holding temperature of 600 ° C. for 1 hour. . Then, the electric furnace was opened and air-cooled. The nanoshell carbon catalyst was then removed and stored in a sample bottle.

  And the Kune-Fenergel reaction which used the catalyst prepared by doping nitrogen to a nanoshell carbon catalyst in this way as a solid base catalyst was performed like the above-mentioned Example 1, and the yield was measured.

  As a result, the yield of ethyl cyanocinnamate was 21.3%. That is, as described above, since the yield in the case of performing without a catalyst was 5.3%, by using a nanoshell carbon catalyst into which nitrogen was introduced by an ammoxidation method as a solid base catalyst, The yield in the Nefenagel reaction could be increased significantly.

It is explanatory drawing which shows the example about the relationship between the process conditions in the manufacturing method of the solid base catalyst which concerns on one Embodiment of this invention, and the yield of a carbon material. It is explanatory drawing which shows the example about the relationship between the processing temperature in the manufacturing method of the solid base catalyst which concerns on one Embodiment of this invention, and the conversion rate and yield in a Kunafenergel reaction. It is explanatory drawing which shows the example about the relationship between the processing time in the manufacturing method of the solid base catalyst which concerns on one Embodiment of this invention, and the conversion rate and yield in a Kunafenergel reaction. It is explanatory drawing which shows the example about the relationship between the ammonia concentration in the process gas in the manufacturing method of the solid base catalyst which concerns on one Embodiment of this invention, and the conversion rate and yield in a Kunafenergel reaction. It is explanatory drawing which shows the example about the relationship between the processing temperature in the manufacturing method of the solid base catalyst which concerns on one Embodiment of this invention, and the conversion rate and yield in transesterification. It is explanatory drawing which shows an example of the process schedule in the manufacturing method of the solid base catalyst which concerns on one Embodiment of this invention. It is explanatory drawing which shows the example about the relationship between the process schedule shown in FIG. 6, and the yield in Kunefenergel reaction. It is explanatory drawing which shows the other example of the processing schedule in the manufacturing method of the solid base catalyst which concerns on one Embodiment of this invention. It is explanatory drawing which shows the example about the relationship between the process schedule shown in FIG. 8, and the yield in Kunafenergel reaction.

Claims (8)

A heating step of heating the carbon material to increase its temperature;
A holding step of holding the carbon material at an elevated predetermined temperature;
A cooling step of cooling the carbon material to reduce its temperature;
Including
A solid base catalyst in which ammonia gas is brought into contact with the carbon material in the temperature raising step and the holding step, and further, ammonia gas is brought into contact with the carbon material in the cooling step, and the carbon material is doped with nitrogen. A process for producing a solid base catalyst, characterized by comprising: The predetermined temperature in the holding step is in a range of 400 ° C to 800 ° C,
In the cooling step, ammonia gas is brought into contact with the carbon material until the temperature of the carbon material falls within a range of 150 ° C. to 350 ° C., and then contact of the ammonia gas with the carbon material is stopped. A process for producing a solid base catalyst according to claim 1 . Process for the preparation of solid base catalysts according to claim 1 or 2, characterized in that contacting the air with ammonia gas in the carbon material. Solid base catalyst which is characterized by being manufactured by the manufacturing method according to any of claims 1 to 3. The solid base catalysts described in 請 Motomeko 4, how you characterized by using as a solid base catalyst in a chemical reaction. The method according to claim 5 , wherein the chemical reaction is a carbon-carbon bond forming reaction. The method according to claim 6 , wherein the carbon-carbon bond forming reaction is a Kunafenergel reaction or an aldol reaction. The method according to claim 5 , wherein the chemical reaction is a transesterification reaction.

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