Patent Application
20160067699
The disclosure of Japanese Patent Application enumerated below including specification, drawings and claims is incorporated herein by reference in its entirety: No. 2014-182367 filed on Sep. 8, 2014.
1. Field of the Invention
The invention relates to a catalyst structure including a catalyst layer and a manufacturing technology thereof.
2. Description of the Related Art
In the chemical industry, various catalysts are used to accelerate a reaction rate of a specific chemical reaction. For example, in JP2005-66463A, a plurality of active sites are formed by preparing sol-like or paste-like discharge liquids containing active species (catalyst particles) of a plurality of catalysts different from each other and discharging each discharge liquid to a surface of a glass substrate or a metal substrate from an ink jet nozzle in sequence to laminate the active species.
In a catalyst used in the chemical industry, catalyst particles such as metal like gold or platinum, alloy, metal oxide, metal hydroxide or the like are supported on a catalyst support. This catalyst support is not actively involved in a catalyst reaction, but interfaces between the catalyst support and the catalyst particles function as reaction sites or active sites of the catalyst reaction. Thus, a technology to improve a specific surface area (=surface area per unit mass or surface area per unit volume) is desired to enhance a catalyst function.
However, in the above invention described in JP2005-66463A, the glass substrate or the metal substrate functions as the catalyst support and a catalyst structure is configured by supporting the active species (catalyst particles) on the surface of the catalyst support. Thus, there has been a certain limit to the improvement of the specific surface area in the invention described in JP2005-66463A.
The invention was developed in view of the above problem and aims to provide a catalyst structure having an excellent catalyst function and a technology to manufacture the catalyst structure.
According to a first aspect of the invention is a catalyst structure, and comprises a catalyst layer in which a plurality of supported catalysts each including a particulate catalyst support and catalyst particles having a smaller diameter than the catalyst support and supported in a dispersed manner on a surface of the catalyst support are bound by a binder.
According to a second aspect of the invention is a catalyst structure manufacturing method to manufacture a catalyst structure including a catalyst layer, and comprises: a preparation step of preparing a fluid material by mixing supported catalyst including a particulate catalyst support and catalyst particles having a smaller diameter than the catalyst support and supported in a dispersed manner on a surface of the catalyst support, a binder and a liquid containing water or a solvent; and a catalyst layer formation step of forming the catalyst layer by the fluid material.
According to a third aspect of the invention is a catalyst structure manufacturing apparatus to manufacture a catalyst structure including a catalyst layer, and comprises: a discharge nozzle part to discharge a fluid material that is includes a supported catalyst including a particulate catalyst support and catalyst particles having a smaller diameter than the catalyst support and supported in a dispersed manner on a surface of the catalyst support, a binder, a liquid containing water or a solvent; and a moving mechanism to relatively move a base material or a manufacturing jig with respect to the discharge nozzle part; wherein the fluid material is discharged from the discharge nozzle part toward a principal surface of the base material or a flat surface of the manufacturing jig while the base material or the manufacturing jig is relatively moved with respect to the discharge nozzle part by the moving mechanism so that the fluid material is applied onto the principal surface of the base material or the flat surface of the manufacturing jig.
According to the catalyst structure, the catalyst structure manufacturing method and apparatus according to the invention, the catalyst layer as a constituent element of the catalyst structure is formed by binding the plurality of supported catalysts each including the particulate catalyst support and the catalyst particles having a smaller diameter than the catalyst support and supported in a dispersed manner on the surface of the catalyst support by the binder. Thus, a specific surface area can be drastically improved and a catalyst function can be enhanced as compared with the catalyst structure described in JP2005-66463A, i.e. a catalyst structure in which a fine domain (area formed by catalyst particles) is formed on a catalyst support (substrate) having a shape substantially equal to a final shape of the catalyst structure.
The above and further objects and novel features of the invention will more fully appear from the following detailed description when the same is read in connection with the accompanying drawing. It is to be expressly understood, however, that the drawing is for purpose of illustration only and is not intended as a definition of the limits of the invention.
In this manufacturing apparatus MA, a stage moving mechanism 2 is provided on a base B and a stage 3 to hold the base material 11 is movable in an X-Y plane shown in
The stage moving mechanism 2 includes an X-direction moving mechanism 21 to move the stage 3 in an X direction and a Y-direction moving mechanism 22 to move the stage 3 in a Y direction from the bottom. The X-direction moving mechanism 21 is structured such that a ball screw 212 is connected to a motor 211 and a nut 213 fixed to the Y-direction moving mechanism 22 is engaged with the ball screw 212. A guide rail 214 is fixed above the ball screw 212. When the motor 211 rotates, the Y-direction moving mechanism 22 smoothly moves in the X direction along the guide rail 214 together with the nut 213.
The Y-direction moving mechanism 22 also includes a motor 221, a ball screw mechanism (not shown in the figure) and a guide rail 224. When the motor 221 rotates, the stage 3 is moved in the Y direction along the guide rail 224 by the ball screw mechanism. By the above configuration, a relative moving direction of the head part 5 with respect to the base material 11 is made changeable. Each motor of the stage moving mechanism 2 is controlled by a controller 4 to control the entire apparatus.
In the head part 5, a discharge nozzle part 52 to discharge a fluid material (sign 10 in
The light irradiation part 53 is connected to a light source unit 532 to generate ultraviolet rays via an optical fiber 531. Although not shown in the figure, the light source unit 532 includes a shutter openable and closable on a light emitting part thereof, and emitted light can be on-off controlled and the light quantity thereof can be controlled by the opening/closing and an aperture of the shutter. The light source unit 532 is controlled by the controller 4.
Further, the light irradiation part 53 has substantially the same dimension as the nozzle base 520 in the Y direction to irradiate light to the entire fluid material discharged from the plurality of discharge ports 521a, and the lower end thereof serves as a lens 532 to condense the light.
A material of the tip nozzles 521 is not particularly limited. For example, silicon or zirconia crystals can be used in that contaminants are not mixed with the fluid material discharged from the discharge ports 521a and fine processing is possible. Any of the plurality of tip nozzles 521 provided in the head part 5 has the same shape. By setting the shapes of all such tip nozzles requiring a fine processing identical, processing cost of the tip nozzles and, consequently, cost of the entire apparatus can be reduced. Further, if the plurality of tip nozzles each including one discharge port and having the same shape is detachably attached to the nozzle base, it suffices to exchange only the troubled tip nozzle, for example, when any of the discharge ports is clogged or damaged by the fluid material. Thus, the above arrangement is advantageous also in running cost of the apparatus as compared with the case where the entire discharge nozzle part is exchanged.
The light irradiation part 53 is provided downstream of the discharge nozzle part 52 in a base material moving direction X, and irradiates light L (e.g. ultraviolet rays) to the fluid material 10 applied to the base material 11. In the first embodiment, a photo-curable binder resin is contained as a “binder” of the invention as described later. Thus, at a light irradiation position P2 where the light L is irradiated onto the base material 11, the curing of the fluid material 10 on the base material 11 starts upon receiving light irradiation from the light irradiation part 53. In this way, this apparatus MA can form a rod shaped catalyst part (sign 13 in
Further, the catalyst layer 12 formed by the manufacturing apparatus MA shown in
Note that, in this embodiment, silica (SiO2), alumina (Al2O3), titanium oxide (TiO2) or the like in a powder state having a particle diameter of 1 to 100 [μm] is used as the catalyst supports 141 to form the catalyst part 13 using an application technology using the discharge nozzle part 52 to be described in detail next. Further, to exert the catalyst function by the supported catalysts 14, particles of a single element such as gold (Au), platinum (Pt) or palladium (Pd), an oxide or hydroxide thereof having a smaller diameter than the catalyst supports 141 are used as the catalyst particles 142 in this embodiment.
Next, a method to manufacture the above catalyst structure 1A by the aforementioned manufacturing apparatus MA is described with reference to
Then, the base material 11 is carried into the apparatus MA in which a preparation for manufacturing the catalyst structure 1A is completed as described above, and placed on the stage 3 (Step S2). Then, the stage moving mechanism 2 is operated to move the base material 11 to a predetermined application start position (position of the base material 11 in
Subsequently, the discharge of the fluid material and light irradiation from the discharge nozzle part 52 and the light irradiation part 53 provided in the head part 52 are respectively started while the base material 11 is moved in the X direction (Step S4). The fluid material 10 is continuously discharged into rod shape from the tip nozzles 521, whereby the fluid material 10 is applied in a plurality of (four in this embodiment) rods (e.g. having a cross-sectional shape with a width of 70 [μm] in the Y direction and a height of 150 [μm] in the Z direction and extending in the X direction) parallel to each other on the base material 11 and the catalyst parts 13 extend in the X direction. Further, by irradiating ultraviolet rays from the light irradiation part 53 provided downstream of the discharge nozzle part 52 in the base material moving direction X, the catalyst parts 13 are cured and a convex shape is maintained in a YZ plane. Furthermore, inside the catalyst part 13, the supported catalysts 14 are bound to each other by the binder resin 15 as shown schematically in
When the application of the fluid material 10 from one end to the other end of the base material 11 (application step) and light irradiation are finished, a return to the application start position is made and the above operation is repeatedly performed a necessary number of times (Step S5) until the formation of the catalyst parts 13 on the entire surface of the base material 11 is finished. At this time, the rod shaped catalyst parts 13 can be formed on the entire upper surface 111 of the base material 11 as shown in
As described above, in this embodiment, the fluid material 10 prepared by mixing the supported catalysts 14, the photo-curable binder resin (binder) and the liquid component such as water or an organic solvent is applied into rod shape on the upper surface 111 of the base material 11 to form the catalyst layer 12 including of the plurality of catalyst parts 13. In the catalyst layer 12 of the catalyst structure 1A formed in this way, a plurality of supported catalysts 14 each including the particulate catalyst support 141 and the catalyst particles 142 having a smaller diameter than the catalyst support 141 and supported in a dispersed manner on the surface of the catalyst support 141 as shown in
Further, the specific surface area is improved not only inside the catalyst layer 12, but also outside the catalyst layer 12. That is, each catalyst part 13 has a self-standing three-dimensional shape on the upper surface 111 of the base material 11 as shown in
Although the photo-curable binder resin 15 is used as an example of the “binder” of the invention in the above first embodiment, a thermosetting binder resin may be used. A second embodiment of the catalyst structure according to the invention is described below with reference to
In the second embodiment, the catalyst structure is manufactured in the following manner. First, supported catalysts 14, a thermosetting binder resin and a liquid component such as water or an organic solvent are mixed to prepare a paste-like fluid material 10. Then, this fluid material 10 is stored in a tank 526 in advance. When a base material 11 before a catalyst layer is formed is placed on the stage 3 of the manufacturing apparatus MB, the heating of the stage 3 by the heating unit 31 is started. Note that a heating start timing of the stage 3 is not limited to this and, for example, the heating of the stage 3 may be started by operating the heating unit 31 before the base material 11 is carried into the manufacturing apparatus MB.
The base material 11 is moved to a predetermined application start position (position of the base material 11 in
When the application of the fluid material 10 from one end to the other end of the base material 11 (application step) is finished, a return to the application start position is made and the above operation is repeatedly performed a necessary number of times until the formation of the catalyst parts 13 on the entire surface of the base material 11 is finished as in the first embodiment. At this time, the rod shaped catalyst parts 13 can be formed on the entire upper surface 111 of the base material 11 by moving the position of the base material 11 a predetermined distance in the Y direction every time one operation is finished. When the catalyst structure is manufactured in this way, the catalyst structure is carried out of the manufacturing apparatus MB and accommodated, for example, in a reaction container of a reforming apparatus.
As described above, also in the second embodiment, a catalyst structure having an excellent catalyst function is obtained from the same reason as in the first embodiment.
Although the binder resin is used as the binder to bind the plurality of supported catalysts 14 to each other in the above first and second embodiments, fine particles finer than the catalyst supports may be used. More specifically, fine particles of silica (SiO2), alumina (Al2O3), titanium oxide (TiO2) or the like can be used. In this case, a catalyst structure can be manufactured using the manufacturing apparatus MB shown in
In this third embodiment, a paste-like fluid material 10 is prepared by mixing supported catalysts 14, binder fine particles, a liquid component such as water or an organic solvent. Then, this fluid material 10 is stored in a tank 526 in advance. When a base material 11 before a catalyst layer is formed is placed on the stage 3 of the manufacturing apparatus MB, the stage 3 is heated by the heating unit 31, the base material 11 is moved to the application start position and the fluid material is discharged from the discharge nozzle part 52 while the base material 11 is relatively moved with respect to the head part 5 as in the second embodiment. This causes the fluid material 10 to be applied into a plurality of rods parallel to each other on an upper surface 111 of the base material 11 and rod shaped catalyst parts 13 extend in the X direction. Further, inside the catalyst part 13, the binder fine particles 17 enter between the supported catalysts 14 to bind the supported catalysts 14 to each other and many voids 16 are formed by the evaporation of a part of the liquid component as shown in
When the application of the fluid material 10 from one end to the other end of the base material 11 is finished, a return to the application start position is made and the above operation is repeatedly performed a necessary number of times until the formation of the catalyst parts 13 on the entire surface of the base material 11 is finished as in the first and second embodiments. In this way, the rod shaped catalyst parts 13 can be formed on the entire upper surface 111 of the base material 11. When the catalyst structure is manufactured in this way, the catalyst structure is carried out of the manufacturing apparatus MB and accommodated, for example, in a reaction container of a reforming apparatus.
As described above, also in the third embodiment, a catalyst structure having an excellent catalyst function is obtained from the same reason as in the first and second embodiments.
The catalyst structures 1A according to the above first to third embodiments has a so-called line-and-space structure in which the plurality of catalyst parts 13 are formed in parallel on the base material 11 while being separated from each other in a regular interval in the Y direction. Thus, the upper surface 111 of the base material 11 is exposed between the catalyst parts 13 adjacent to each other, and no catalyst reaction occurs in these exposed parts. Contrary to this, a catalyst part having a planar shape (hereinafter, referred to as a “planar catalyst part”) may be formed on the upper surface 111 of the base material 11 and a plurality of rod shaped catalyst parts 13 may be formed on the upper surface of this planar catalyst part as described next. In this case, the specific surface area can be further increased. A fourth embodiment of the invention is described below with reference to
In this manufacturing apparatus MC, a frame 122 different from a frame 121 is so fixed to a base B as to straddle a stage 3 in order to provide the second head part 7. The second head part 7 is attached to the frame 122. Note that the second head part 7 is arranged at a distance from the first head part 5 in a (−X) direction to form the planar catalyst part by the second head part 7 before the rod shaped catalyst parts are formed by the first head part 5.
This second head part 7 includes a base 71, a discharge nozzle part 72 and a light irradiation part 73 similarly to the first head part 5. Further, a tank 726 to store a fluid material containing supported catalysts is connected to the discharge nozzle part 72 via a supply pipe 722, a control valve 723, a pump 724 and a flowmeter 725. The controller 4 controls the opening and closing of the control valve 723, whereby the discharge of the fluid material from the discharge nozzle part 72 is controlled to be on and off.
In the fourth embodiment, a catalyst structure 1B shown in
When a base material 11 before a catalyst layer is formed is placed on the stage 3 of the manufacturing apparatus MC, a stage moving mechanism 2 is operated to move the base material 11 to a predetermined application start position (position of the base material 11 in
By discharging the fluid material 10A from the tip nozzle 721, the fluid material 10 is applied wide in the Y direction on the base material 11, thereby planar catalyst part 18 is formed (refer to
When the formation of the planar catalyst part 18 from one end to the other end of the base material 11 is completed, the application of the fluid material 10A and light irradiation are finished. When the formation of the rod shaped catalyst parts 13 from the one end to the other end of the base material 11 is subsequently completed, the application of the fluid material 10B and light irradiation are finished. A return to the application start position is made and the above operation is repeatedly performed a necessary number of times until such formation of the catalyst parts 18, 13 on the entire surface of the base material 11 is finished. At this time, the position of the base material 11 is moved a predetermined distance in the Y direction every time one operation is finished. In this way, the catalyst layer 12 formed by laminating the planar catalyst part 18 and the plurality of rod shaped catalyst parts 13 on the entire upper surface 111 of the base material 11 is formed on the upper surface of the base material 11 to manufacture the catalyst structure 1B. Thereafter, the catalyst structure 1B is carried out of the manufacturing apparatus MC and accommodated in a reaction container of a reforming apparatus.
As described above, in the fourth embodiment, not only a catalyst structure having an excellent catalyst function is obtained from the same reason as in the first to third embodiments, but also the planar catalyst part 18 is exposed between the rod shaped catalyst parts 13 adjacent to each other. Thus, the specific surface area can be more improved than in the first to third embodiments.
In the fourth embodiment, the catalyst layer 12 is formed by forming the rod shaped catalyst parts 13 on the upper surface of the planar catalyst part 18 formed on the upper surface 111 of the base material 11 and the planar catalyst part 18 and the rod shaped catalyst parts 13 are integrated in the catalyst layer 12. As shown in
As described above, the binder resin 15 or the binder fine particles 17 are used as the “binder” of the invention in each of the above embodiments, but specific examples of usable “binder” include “polyvinylidene difluoride (PVDF: PolyVinylidene DiFluoride), styrene-butadinene rubber (SBR: Styrene-Butadinene Rubber), carboxymethyl cellulose (CMC: CarboxyMethyl Cellulose), nano-silica, nano-alumina, and nano-titanium oxide. Further, the rod shaped catalyst parts 13 and the planar catalyst part 18 respectively correspond to an example of “first shape catalyst parts” and an example of a “second shape catalyst part” of the invention.
Further, in the above embodiments, a step of preparing the fluid material (Step S1, etc.) corresponds to an example of a “preparation step” of the invention, and a step of forming the catalyst part(s) by the discharge of the fluid material from the head part(s) 5, 7 corresponds to an example of a “catalyst layer formation step” of the invention.
Note that the invention is not limited to the aforementioned embodiments and various changes other than the aforementioned ones can be made without departing from the gist of the invention. For example, a plurality of catalyst structures (=base materials 11+catalyst layers 12) according to the above first to fourth embodiments may be combined. For example, an assembly obtained by laminating a plurality of catalyst structures 1A as shown in
Further, in the above embodiments, the rod shaped catalyst part 13 having a cross-sectional shape with a width of 70 [μm] in the Y direction and a height of 150 [μm] in the Z direction is formed as the “first shape catalyst part” of the invention. However, the rod shaped catalyst part 13 has only to have a self-standing three-dimensional shape. Examples of the “first shape catalyst part” of the invention include a catalyst part 13 having a rectangular parallelepipedic shape with a width of 30 to 300 [μm] in the Y direction and a height in the Z direction, which is 0.2 to 3 folds of the width in the Y direction, an island shaped catalyst part 13 and the like.
Further, although the plurality of rod shaped catalyst parts 13 are provided in stripes in a plan view as shown in
Although the shapes of the catalyst parts 13, 18 are maintained utilizing the photo-curable property or thermosetting property of the binder in the above embodiments, the shape may be maintained by preparing the fluid material 10 having a relatively high viscosity or controlling the viscosity of the catalyst parts immediately after application using a quick-drying solvent such as acetone or alcohols as the liquid component.
Further, although the catalyst layer 12 is formed only on the one principal surface 111 of the base material 11 in the above first to fourth embodiments, a catalyst layer may be formed on the other principal surface of the base material 11, too.
Furthermore, although the invention is applied to the catalyst structure that functions as a reforming catalyst to produce reformed gas in the above embodiments, an application target of the invention is not limited to this and the invention can be applied to catalysts in general used in the chemical industry.
Although the invention has been described with reference to specific embodiments, this description is not meant to be construed in a limiting sense. Various modifications of the disclosed embodiment, as well as other embodiments of the invention, will become apparent to persons skilled in the art upon reference to the description of the invention. It is therefore contemplated that the appended claims will cover any such modifications or embodiments as fall within the true scope of the invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2014-182367 | Sep 2014 | JP | national |
