JP5888718B2 - Catalytic body and method of chemical reaction of substance using the catalytic body - Google Patents

Description

The present invention relates to a catalyst body useful for applications such as various filters, microreactors, adsorbents or fillers, and a method for chemical reaction of a substance using the catalyst body .

  As conventional catalyst bodies, Patent Documents 1 to 7 describe those in which an anodized film (alumite film) is formed on the surface of an aluminum substrate and the catalyst is supported in the fine pores formed in the film.

  Further, cited references 8 to 12 describe a technique in which a catalyst support layer is attached to a metal substrate and a catalyst is supported on the catalyst support layer.

  In the catalyst body, conventionally, the surface area of a plate-like or foil-like metal material is enlarged to support the catalyst, and the catalyst body is cut into a size suitable for placement in the reaction channel. Therefore, it was arranged in the reaction channel.

  Alternatively, since the catalyst activity depends on the surface area of the catalyst support, conventionally, in order to increase the surface area of the catalyst support, the catalyst support is made fine particles and the catalyst is supported on the catalyst support, as shown in FIG. In addition, the plurality of finely divided catalyst bodies a were filled in the reaction flow path b.

  Conventionally, the catalyst body is heated using a heater or the like to control the temperature, thereby increasing the catalytic activity.

JP 59-59247 A JP-A-2-144154 JP-A-8-246190 JP-A-10-73226 JP 2002-119856 A JP 2007-237090 A JP 2008-126151 A Japanese Patent Laid-Open No. 10-281690 JP-A-8-332394 JP 2007-44574 A Japanese Patent No. 4263268 JP 2008-259968 A

  However, the plate-like or foil-like catalyst body needs to be cut to a size suitable for being arranged in the reaction flow path, so that the cost becomes high. Moreover, since the surface which does not carry | support a catalyst body is exposed by cutting, there existed a fault that the volumetric efficiency (surface area / volume) of the surface area which controls catalyst activity fell.

  In addition, when the reaction flow path b is filled with the finely divided catalyst body a, the flow of the reaction gas in the reaction flow path b is blocked by the filled finely divided catalyst body a, so that the pressure loss is large. There was a drawback.

  Further, since the temperature control of the catalyst body is heated by a heater (not shown) provided outside the reaction channel b, the heat conduction of the reaction system such as the reaction channel b is insufficient, It could not be heated sufficiently, and precise temperature control of the catalyst body was difficult, and for example, it could not be applied to a precise chemical reaction system such as a microreactor.

  The present invention eliminates the above-mentioned drawbacks.

  In the present invention, an aluminum wire (including an aluminum alloy wire; the same shall apply hereinafter) is prepared as a catalyst carrier. Alternatively, a catalyst support is prepared by forming a surface area enlarged shape that enlarges the area of the wire surface on the surface of the aluminum wire.

  Examples of the surface area-enlarged shape include a rugged shape, through or non-through holes, hollow pores (pits), and a porous layer having a spongy structure with continuous fine pores (a spongy structure layer). )

  In addition, the aluminum wire or the aluminum wire formed with the surface area enlarged shape is anodized to form an anodized film (alumite film) on the surface of the aluminum wire to form a catalyst carrier. The aluminum wire may be further hydrated to form an aluminum hydroxide film (hydrated film), which may be fired to form a catalyst carrier.

  Alternatively, the aluminum wire or the aluminum wire formed with the surface area enlarged shape is hydrated to form an aluminum hydroxide film (hydrated film), which is fired to form a catalyst carrier.

  Thereafter, the catalyst is supported on the catalyst carrier to form a catalyst body.

  The wire diameter of the aluminum wire is selected according to the size of the reaction channel, and is preferably 5 μm to 5 mm, particularly preferably 5 μm to 2 mm. In addition, although the cross-sectional shape of the said wire is circular, for example, it does not necessarily need to be a perfect circle. Moreover, the cross-sectional shape of the wire may be elliptical or rectangular other than circular.

  Moreover, the formation method of the said surface area expansion shape is not specifically limited, For example, there exist physical methods, such as the chemical and electrochemical etching process method in an acid solution, vacuum deposition, shot blasting, and machining.

  Moreover, the thickness of the surface area enlarged shape layer formed on the aluminum wire is not particularly limited, but a thickness of 50% or less of the wire diameter is preferable in order to ensure physical strength.

  Further, the uneven shape, the through or non-penetrating hole is formed by a physical, chemical or electrochemical method, and the size and depth thereof are not particularly limited, for example, a size of several mm to several nm, Formed in depth.

  Moreover, the method of creating the hollow-shaped pore (pit) by the said electrochemical method, for example, as shown in FIG. 1, the aluminum wire 1 is used in the solution (for example, hydrochloric acid) bath 2 containing a halogen ion. Electrolytic treatment is performed with direct current to generate hollow pits, and then the electrolytic treatment is performed with direct current in a neutral or acidic solution to enlarge the diameter of the pits.

  The pits of the aluminum wire may be formed obliquely other than being perpendicular to the surface of the aluminum wire.

  The pit diameter formed on the aluminum wire is preferably a minimum pit diameter of 0.1 μm or more and an average pit diameter of 0.3 to 5 μm. In particular, the minimum pit diameter is 0.3 μm or more. The diameter is preferably 0.5 μm or more.

  2 shows an oxide replica having a plurality of pits on the surface of an aluminum wire (an oxide formed by covering an aluminum wire with an oxide for pit observation and then dissolving and removing the aluminum portion). FIG. 3 shows an enlarged SEM photograph of the pit portion of FIG. 2, and 3 shows a plurality of pits formed on the surface of the aluminum wire.

  In addition, as shown in FIG. 4, for example, as shown in FIG. 4, an aluminum wire 1 is electrolytically treated by alternating current in a solution (for example, hydrochloric acid) bath 2 containing halogen ions as shown in FIG. Let me. By this electrolytic treatment, corrosion and film formation are alternately repeated on the surface of the aluminum wire 1 to form a spongy structure layer in which fine pores are connected.

  The thickness of the spongy structure layer formed on the surface of the aluminum wire is not particularly limited. However, when the thickness is less than 1 μm, the decomposition activity decreases. When the thickness is greater than 100 μm, the decomposition activity does not improve and only the pressure loss increases. Therefore, a thickness of 1 to 100 μm from the surface is preferable.

  Further, if the pore size of the spongy structure layer is too large, the amount of catalyst supported decreases, so the average pore size is 1000 nm at the maximum, and 25 to 300 nm is particularly preferable.

  5 shows an SEM photograph of a cross section of the aluminum wire on which the sponge-like structure layer is formed, and FIG. 6 shows an enlarged schematic view of a part of the sponge-like structure layer of FIG. 4 is a spongy structure layer and 5 is a micropore.

  In addition, although the said sponge-like structure layer shows the example of the sponge-like structure layer with which the nano-sized micropore 5 which can carry | support a catalyst was shown, the magnitude | size of the pore of a sponge-like structure layer is especially limited. Alternatively, the micro pores having a size larger than that may be connected.

  The anodizing treatment is for further increasing the surface area of the aluminum wire surface, and is carried out in an acidic electrolytic bath, phosphoric acid, sulfuric acid, oxalic acid, chromic acid, sulfasalicylic acid, pyrophosphoric acid, sulfamic acid, phosphomolybdic acid. , Malonic acid, maleic acid, succinic acid, tartaric acid, phthalic acid, citric acid, itaconic acid, malic acid, glycolic acid, boric acid, etc.

  After the alumite film is formed, the diameter of the formed micropores may be further expanded by pore widening treatment by acid immersion.

  7 shows a schematic diagram of an aluminum wire having an alumite film on the surface in the pit 3 after anodic oxidation, 6 is an alumite film formed on the surface in the pit 3 of the aluminum wire 1, A large number of fine holes formed on the alumite film 6.

  The hydration treatment is for further increasing the surface area of the aluminum wire surface. For example, when an aluminum wire is hydrated, the surface of the aluminum wire, the uneven surface, the surface in the hole A film of aluminum hydroxide is formed on the inner surface of the pits and the surface of the micropores in the sponge-like structure layer. Moreover, a hydration process liquid is not specifically limited, For example, it carries out with 10-100 degreeC water, warm water, or hot water. Moreover, you may add triethanolamine, ammonia, sodium silicate, etc. as a reaction accelerator.

  8 shows an SEM photograph of an enlarged cross section in the vicinity of the pit of the aluminum wire having a hydrated film. 8 is a hydrated film formed on the surface of the pit 3 of the aluminum wire 1, and the hydrated film In FIG. 8, a large number of fine holes are formed.

  The firing treatment further expands the surface area of the aluminum wire by dehydrating moisture in the hydrated film and forming an alumina layer. If the firing temperature is less than 300 ° C., the alumina is not sufficiently produced. Since the substrate is damaged at a temperature higher than 550 ° C. and the surface area is lowered, it is not preferable. Therefore, the temperature is 300 to 550 ° C. for 5 minutes to 3 hours.

  The metal having catalytic activity supported on the catalyst carrier is not particularly limited, and examples thereof include known metals, alloys or metal compounds having catalytic activity. For example, platinum metal, platinum metal compound, palladium, rhodium, indium, silver, rhenium, tin, cerium, zirconium, gold, gold alloy, manganese, iron, zinc, copper, nickel, nickel alloy, cobalt, cobalt alloy It is desirable to select from a metal such as ruthenium, a compound such as an oxide or carbonate. Moreover, you may combine these catalyst substances.

  In the method of supporting the catalyst on the catalyst carrier, for example, a metal having catalytic activity is adsorbed on the film or the sponge-like structure layer, and further fixed so as not to be desorbed even when contacted with a substance used for the catalytic reaction.

  Specifically, for example, known methods such as an impregnation method, an electrodeposition method, an ion exchange method, a coprecipitation method, a deposition method, a hydrothermal synthesis method, and a gas phase synthesis method are used. In particular, an impregnation method of immersing in an aqueous solution containing metal ions having catalytic activity is preferable. The aqueous solution used for the impregnation method can be prepared by using a chloride, bromide, ammonium compound, cyanide, alkali metal salt, or a complex compound thereof containing a metal having catalytic activity.

  In addition, a calcination treatment can be performed to fix a metal having catalytic activity.

  Further, as shown in FIG. 9, the plurality of aluminum wires 1 are separated from each other and arranged in parallel, and one end portion and the other end portion of the plurality of wires are fixed by wire fixing frames 9a and 9b. The catalyst body is formed in a reaction channel 10 to which a substance such as a gas that undergoes a chemical reaction such as decomposition is supplied by the catalyst body, and the direction of the wire of the catalyst body is relative to the direction of the reaction channel 10. Arrange them in parallel.

  When the reaction channel of the substance is curved, the plurality of aluminum wires are also curved with the same curvature as the curve of the reaction channel, and the direction of the wire of the catalyst body is relative to the direction of the supply passage. Make sure they are arranged in parallel.

Further, as shown in FIG. 10, the wire fixing frame 9a, 9b and respectively made of metal, the respective frame to each electrode terminal portions 11a, allowed connects 11b, the power supply unit between the electrode terminal portions 11 a, 11 b 12 is connected so that a current flows through the wire 1 and the temperature of the catalyst body can be adjusted by energizing the wire 1.

  In the present invention, since the catalyst body is in the form of a wire, there is a great advantage that a catalyst body excellent in volumetric efficiency can be installed in the reaction channel.

Further, since the wires of the catalyst body are arranged so that their directions are separated from and parallel to the direction of the reaction flow path, there is a great advantage that the pressure loss of the reaction gas can be reduced.

  In addition, since the current is directly supplied to the catalyst body, the temperature of the catalyst body can be precisely controlled. Therefore, for example, a catalyst body suitable for a highly accurate chemical reaction system such as a microreactor can be obtained.

It is explanatory drawing of the apparatus used in order to form the pit of this invention. It is a SEM photograph of the section of the oxide replica which has a pit of the present invention. It is the SEM photograph which expanded the pit part of FIG. It is explanatory drawing of the apparatus used in order to form the sponge-like structure layer of this invention. It is a SEM photograph of the section of the wire made from aluminum which has the spongy structure layer of the present invention. It is the schematic diagram which expanded the one part cross section of the sponge-like structure layer of the wire made from aluminum which has the sponge-like structure layer of this invention. It is a schematic diagram of the wire made from aluminum which has the alumite film | membrane of this invention. It is a SEM photograph of an expanded section of an aluminum wire having a hydrated film of the present invention. It is explanatory drawing of the other Example of the catalyst body of this invention. It is explanatory drawing of other Example of the catalyst body of this invention. It is explanatory drawing of the conventional catalyst body. It is explanatory drawing of the conventional catalyst body. It is explanatory drawing of the catalyst body of this invention. It is explanatory drawing of the conventional catalyst body.

The catalyst body of the present invention includes a plurality of aluminum wires supporting a catalyst and the plurality of aluminum wires arranged in the reaction channel, and separated from each other in parallel to the direction of the reaction channel. The wire fixing frame for fixing the one end and the other end of the plurality of wires is made of metal, and the wire fixing frame for fixing the one end and the other end of the plurality of wires is made of metal, respectively. the power supply terminal portion is connected, the power supply unit between the power source terminal portion is characterized by comprising connected.

  The wire diameter of the aluminum wire is 5 μm or more.

Moreover, the surface area expansion shape which expands the surface area of this wire surface is formed in the said aluminum wire surface, It is characterized by the above-mentioned. Further, the surface area enlarged shape is a concavo-convex shape, a penetrating or non-penetrating hole, a pit, or a spongy structure layer.

  Moreover, the film by the anodizing process is formed in the surface of the said aluminum wire.

  The surface of the aluminum wire is characterized in that a film that has been hydrated after being anodized is formed.

  Further, the surface of the aluminum wire is characterized in that a film that is hydrated after anodizing and then fired is formed.

  Moreover, the film | membrane by the hydration process is formed in the surface of the said aluminum wire.

  The surface of the aluminum wire is characterized in that a film baked after being hydrated is formed.

  Moreover, the manufacturing method of the catalyst carrier includes a first step of forming a surface area expanding shape for expanding the surface area of the wire surface on the surface of the aluminum wire, and a second step of anodizing the aluminum wire. It is characterized by becoming.

  Moreover, the manufacturing method of the catalyst carrier includes a first step of forming on the surface of the aluminum wire a surface area expanding shape for expanding the surface area of the wire surface, and a second step of hydrating the aluminum wire. And a third step of firing the aluminum wire.

  In the catalyst body of the present invention, the catalyst is supported on the catalyst carrier.

  The catalyst body of the present invention further includes a fixing means for fixing the plurality of aluminum wires in parallel with each other.

  The catalyst body of the present invention is characterized in that the aluminum wire is further provided with energization means for energizing the wire.

  In the chemical reaction method for a substance of the present invention, the plurality of aluminum wires are arranged in parallel to the supply direction of the substance that is chemically reacted by the catalyst body, and the substance is supplied to the catalyst body. The substance is chemically reacted.

  The method for chemical reaction of a substance of the present invention is characterized in that the aluminum wire is energized, the substance is supplied to the catalyst body, and the substance is chemically reacted.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in full detail, this invention is not limited by this.

  (Comparative Example 1)

  A plate-shaped catalyst body is cut to form a catalyst body having a length L and a cross-sectional shape of a square having a side 2R as shown in FIG. 11, and a plurality of the catalyst bodies as shown in FIG. It was placed in the reaction channel of the substance. In FIG. 11, the A surface is a cut surface, and the B surface is a non-cut surface. The effective surface area per unit volume (surface area / volume carrying the catalyst) of this catalyst body is (2 × 2R × L) / (2R × 2R × L) = 1 / R.

  The catalyst body is formed by etching the surface of the aluminum plate to form an enlarged surface area, and the aluminum plate is anodized for 16 hours in an aqueous solution having a bath temperature of 20 ° C. and an oxalic acid concentration of 5 wt%. Next, it was calcined at 350 ° C. for 1 hour, then hydrated at 80 ° C. for 2 hours, and calcined at 500 ° C. for 3 hours to form.

As shown in FIG. 13, the wire was cut and a plurality of catalyst bodies made of wires having a length of L and a radius of R were arranged in the substance supply flow path as shown in FIG. In FIG. 13, the A surface is a cut surface, and the B surface is a non-cut surface. The effective surface area (surface area / volume carrying the catalyst) per unit volume of the catalyst body is (2πR × L) / (πR ² × L) = 2 / R. The catalyst body was molded in the same manner as in Comparative Example 1.

  From the above results, the effective surface area of the cut plate-shaped catalyst body was 1 / R, the effective surface area of the wire-shaped catalyst body was 2 / R, and the present invention had a larger effective surface area and was superior. It turned out to be performance.

DESCRIPTION OF SYMBOLS 1 Aluminum wire 2 Bath 3 Pit 4 Sponge-like structure layer 5 Fine hole 6 Anodized film 7 Fine hole 8 Hydrated film 9 Wire fixing frame 10 Reaction flow path 11 Electrode terminal part 12 Power supply part

Claims (5)

A plurality of aluminum wires carrying a catalyst disposed in the reaction channel;
The plurality of aluminum wires are separated from each other and are parallel to the direction of the reaction flow path, and comprise a wire fixing frame that fixes one end and the other end of the plurality of wires,
Wherein the plurality of wire fixing frame for fixing the one end and the other end of the wire respectively made of metal, this to each frame the power supply terminal portion are connected, that the power unit is connected between the power source terminal portion Characteristic catalyst body.   The catalyst body according to claim 1, wherein a wire diameter of the aluminum wire is 5 μm or more.   3. The catalyst body according to claim 1, wherein the surface of the aluminum wire is formed with a surface area expansion shape that expands the surface area of the wire surface. 4.   4. The catalyst body according to claim 3, wherein the surface area enlarged shape is an uneven shape, a through or non-through hole, a pit, or a spongy structure layer. The substance to be chemically reacted by the catalyst body is supplied to the catalyst body described in any one of claims 1 to 4, a chemical reaction method of a substance, characterized in Rukoto react chemically with the substance.

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