This application claims the benefit of Taiwan application Serial No. 98108329, filed Mar. 13, 2009, the subject matter of which is incorporated herein by reference.
1. Field of the Invention
The invention relates in general to a catalyst and a manufacturing method thereof, and more particularly to a catalyst for catalyzing a hydrogen releasing reaction and a manufacturing method thereof.
2. Description of the Related Art
In recent years, fuel cell has become the main trend in the development of green energy while resources are getting more and more limited. A hydrogen fuel cell uses hydrogen as fuel and oxygen as oxidant. Hydrogen is dangerous and flammable gas with strict storage conditions. Therefore, hydride solution or hydrogen storage material containing hydrogen is usually used as hydrogen source instead. Hydrogen is extracted from the hydrogen source for the fuel cell.
However, the fuel cell nowadays still cannot be applied to daily life widely. One of the reasons is that the hydrogen-releasing rate to extract hydrogen from the hydrogen source is too low, which results in insufficient hydrogen. In such conditions, the device has to be large in order to produce the required amount of hydrogen. Another reason is that only nano-scale catalyst has sufficient surface area to meet the requirement of hydrogen-releasing rate when catalyst is in use for increasing the hydrogen-releasing rate of the hydrogen source. However, conventional nano-scale hydrogen releasing catalyst cannot be manufactured rapidly using mass production technologies. The cost of material and equipment is high. As a result, it is difficult to commercialize the nano-scale hydrogen releasing catalyst. For example, conventional hydrogen releasing catalyst includes precious metal, ruthenium and rhodium, and non-precious metal, cobalt, nickel, iron, manganese and copper. Precious metal, ruthenium and rhodium, can provide much higher hydrogen-releasing rate than non-precious metal.
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The invention is directed to a catalyst for catalyzing hydrogen releasing reaction and a method thereof. Metal catalyst ions, metal catalyst atoms, metal catalyst nano-structures or the combination of metal catalyst atoms and nano-structures are formed on the surface of the catalyst supports through chelation and reduction. The catalyst of the embodiments of the present invention increases the hydrogen-releasing rate, and the manufacturing method thereof only includes simple steps. Mass production is achieved rapidly and cheaply so that the product can be commercialized,
According to the first aspect of the present invention, a method of manufacturing a catalyst is provided. The catalyst is used for catalyzing hydrogen releasing reaction. The manufacturing method includes following steps. First, a solution with metal catalyst ions is provided. Next, catalyst supports including plenty of chelating units are provided. Then, the catalyst supports are mixed with the solution, so that the metal catalyst ions chelate with the chelating units on the surface of the catalyst supports. Subsequently, the metal catalyst ions chelating with the surface of the catalyst supports are reduced, so that metal catalyst nano-structures and/or metal catalyst atoms are coated on the surface of the catalyst supports, for forming catalysts.
According to the second aspect of the present invention, a catalyst for catalyzing hydrogen releasing reaction is provided. The catalyst includes a catalyst support of ion exchange resin and metal catalyst atoms formed on the surface of the catalyst support.
According to the second aspect of the present invention, another catalyst for catalyzing hydrogen releasing reaction is provided. The catalyst includes a catalyst support of ion exchange resin and metal catalyst ions. Also, the surface of the catalyst support has several chelating groups. The metal catalyst ions respectively chelate with the chelating groups on the surface of the catalyst support.
The invention will become apparent from the following detailed description of the preferred but non-limiting embodiments. The following description is made with reference to the accompanying drawings.
The file of this patent contains at least one drawing executed in color. Copies of this patent with the color drawing(s) will be provided by the Patent and Trademark Office upon request and payment of the necessary fee.
Exhibit 1 shows pictures of the appearance and the enlarged pictures shot by a scanning electron microscope (SEM) of the catalyst supports, γ-Al2O3, of the control group and the produced catalyst Ru/Al2O3, and the catalyst supports IR-120 of the embodiment and the produced catalyst Ru/IR-120.
A rapid-manufactured catalyst for catalyzing hydrogen releasing reaction and a manufacturing method thereof are provided by the present invention. The manufacturing process is simple, which allows mass production rapidly and cheaply. The catalyst has high hydrogen-releasing rate. The first and second embodiments of the present invention are described as follows. However, the structure of the catalyst and the reaction steps are used as examples and not to limit the scope of the present invention. Moreover, unnecessary elements are not shown in the drawings for clarity
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The particle size of the catalyst support 210 is between 1 μm and 10000 μm. The catalyst support 210 is preferably cation exchange resin, such as MSC-1B, DowEX-HCR-W2, MSC-1A, Amberlyst-15, DowEX-22, DowEX-88 and IR-120. Or, the catalyst support 210 can be anion exchange resin, such as A-26, IRA-400, IRA-900, DowEX-550A, DowEX-MSA-1, DowEX-MSA-2 and A-36. Furthermore, the metal catalyst ions 220 include at least one selected from the group consisting of ruthenium, cobalt, nickel, iron, manganese or copper.
The catalyst 200 for catalyzing hydrogen releasing reaction of the present embodiment is for catalyzing the hydrolysis reaction of hydride and water for producing hydrogen. The hydride is selected from the group consisting of lithium aluminum hydride, sodium aluminum hydride, magnesium aluminum hydride, calcium aluminum hydride, lithium borohydride, sodium borohydride, potassium borohydride, beryllium borohydride, magnesium borohydride, calcium borohydride, lithium hydride, sodium hydride, magnesium hydride and calcium hydride. Before the catalyst powder 200 is used in the hydrolysis reaction of the hydride, the catalyst powder 200 can be ground into particles with particle size around 1 μm to 10 mm, for increasing the total surface area. When the catalyst powder 200 catalyzes the hydrolysis reaction of hydride and water, hydrogen is produced more rapidly.
The manufacturing method of the catalyst 200 is described with reference to the accompanying drawings as follows. Please refer to
First, as shown in the step S31, a solution with metal catalyst ions 220 is provided. The solution is metal salt solution. The molar concentration of the metal catalyst ions 220 in the solution is approximately between 0.001 M and 10 M depending on the practical conditions.
Next, as shown in the step S32, several catalyst supports 210 are provided. Each catalyst support 210 includes several chelating units 211. Moreover, in the step S32, the catalyst support 210 can be broken into evenly sized particles with particle size between 1 μm and 10000 μm by grinding or any other method.
Then, as shown in the step S33, the catalyst supports 210 are added into the solution to form several catalysts 200. In the step S33, the metal catalyst ions 220 in the solution chelate with the chelating units 210 on the surface of each catalyst support 210, for forming the catalysts 200.
Later, as shown in the step S34, the catalysts 200 are collected. The step S34 includes steps of extracting, cleaning and drying the catalysts 200. In the step of drying the catalysts 200, the catalysts 200 are dried in a vacuum environment or inert gas.
Furthermore, in the present embodiment, the operating temperature to manufacture the catalysts 200 is between −20° C. and 80° C. Therefore, the catalysts 200 can be manufactured at room temperature without using the high temperature system in the present invention. Moreover, the present embodiment uses iron exchange resin as the catalyst supports in the chelate reaction to capture metal catalyst ions on the surface. The amount of the chelated metal catalyst ions can be controlled by varying concentration and time. Therefore, the manufacturing process provided by the first embodiment of the present invention is very simple, which allows rapid mass production and low equipment cost.
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The particle size of the catalyst support 310 is between 1 μm and 10000 μm. Similarly, the catalyst support 310 can be cation exchange resin, such as MSC-1B, DowEX-HCR-W2, MSC-1A, Amberlyst-15, DowEX-22, DowEX-88 and IR-120. Or, the catalyst support 310 can be anion exchange resin, such as A-26, IRA-400, IRA-900, DowEX-550A, DowEX-MSA-1, DowEX-MSA-2 and A-36. The metal catalyst atom includes at least one selected from the group consisting of ruthenium, cobalt, nickel, iron, manganese or copper.
Similarly, the catalyst 300 for catalyzing hydrogen releasing reaction of the present embodiment catalyzes the hydrolysis reaction of hydride and water for producing hydrogen. The hydride is selected from the group consisting of lithium aluminum hydride, sodium aluminum hydride, magnesium aluminum hydride, calcium aluminum hydride, lithium borohydride, sodium borohydride, potassium borohydride, beryllium borohydride, magnesium borohydride, calcium borohydride, lithium hydride, sodium hydride, magnesium hydride and calcium hydride. Similar to the first embodiment, before used in the hydrolysis reaction of the hydride, the catalyst powder 200 can be broken into particles with particle size about 1 μm and 10000 μm, for increasing the total surface area. Therefore, when the catalyst catalyzes the hydrolysis reaction of the hydride and water, hydrogen is produced more rapidly.
The manufacturing method of the catalyst 300 of the present embodiment is described as follows with reference to the flow chart. Please refer to
First, as shown in the step S61, a solution with metal catalyst ions 320′ is provided. The solution is metal salt solution. The molar concentration of the metal catalyst ions 320′ is approximately between 0.001 M and 10 M depending on the practical conditions.
Next, as shown in the step S62, several catalyst supports 310 are provided. Each catalyst support 310 includes several chelating units 311. Similarly, in the step S62, the catalyst supports 310 can be broken into evenly-sized particles with particle size between 1 μm and 10 mm.
Then, as shown in the step S63, the catalyst supports 310 are added into the solution. In the step S63, the metal catalyst ions 320′ in the solution chelate with the chelating units 311 on the surface of each catalyst support 310.
Later, as shown in the step S64, the metal catalyst ions 320′ on the catalyst supports 310 are reduced. As a result, several metal catalyst nano-structures 320 and/or metal catalyst atoms are coated on the surface of the catalyst supports 310 to form the catalysts 300.
Also, a method of reducing the metal catalyst ions 320′ in the step S64 is provided as an example by the present embodiment for anyone who has ordinary skill in the field of the present invention. For example, in the step S64, a reducing agent can be used for reducing the metal catalyst ions 320′ to be metal catalyst atoms. All of the metal catalyst atoms may form metal catalyst nano-structures 320. Or, only some of the metal catalyst atoms form metal catalyst nano-structures 320, depending on the practical conditions. Please refer to
Subsequently, as shown in the step S65, the catalysts 300 are collected. The method of collecting catalysts 300 of the present embodiment is similar to that of the first embodiment. The step S65 includes steps of extracting, cleaning and drying the catalysts 300. In the step of drying the catalysts 300, the catalysts 300 are dried in a vacuum environment or inert gas.
Furthermore, in the present embodiment, the operating temperature to manufacture the catalysts 300 is between −20° C. and 80° C. Therefore, through chelation and reduction, the present embodiment uses ion exchange resin to capture metal catalyst ions and then reduces the metal catalyst ions to metal catalyst nano-structures and/or metal catalyst atoms without using high temperature system. When metal catalyst ions are reduced, some of the metal catalyst ions may be reduced to metal catalyst atoms, and others are reduced to metal catalyst nano-structures, depending on the practical conditions. The present invention is not limited thereto. Compared to the conventional method of manufacturing catalyst, the method of manufacturing nano-scale metal catalyst of the present embodiment is easier, which allows mass production rapidly and cheaply. Also, the chelation and reduction can be controlled by varying the concentration and time to improve the production.
One of the related experiments is provided as follows as reference for people having ordinary skill in the art. However, anyone who has ordinary skill in the field of the present invention can understand that the components and steps used in the experiment are only for illustration but not to limit the scope of the present invention. When applied practically, the parameters of the experiment can be adjusted according to the practical conditions. Related experiment—catalyst Ru/IR-120 and catalyst Ru/Al2O3
In the related experiment, the catalyst Ru/IR-120 is manufactured by the method of the second embodiment. The catalyst Ru/Al2O3 is manufactured by the conventional method as a control group.
When the catalyst Ru/IR-120 of the present embodiment is manufactured, strong acid type (cation-type) ion exchange resin IR-120 is used as catalyst supports. Precious metal ruthenium is used as metal catalyst. First, ruthenium ions chelate with the surface of the ion exchange resin IR-120. Then, ruthenium ions on the surface of the resin IR-120 are reduced to ruthenium atoms by sodium borohydride, a strong reducing agent, through chemical reduction. As a result, ruthenium catalyst with nano-scale structure is formed on the surface of the resin IR-120.
The detailed steps of producing the catalyst Ru/IR-120 are described as follows:
Moreover, the catalyst Ru/Ru/Al2O3 is produced by the conventional manufacturing method as a control group. The conventional manufacturing method includes following steps. First, conventional catalyst supports, γ-Al2O3, are in use and ruthenium chloride solution is produced through impregnation. The manufacturing process includes calcinations of supports, impregnation, filtration and drying, high temperature sintering and reduction through hydrogen.
After the catalyst is produced, property analysis of the catalyst and test of the catalyst in catalyzing hydrogen releasing reaction are performed. Attached Exhibit 1 shows the pictures of the appearance and the enlarged pictures shot by a scanning electron microscope (SEM) of the catalyst supports, γ-Al2O3, of the control group and the produced catalyst Ru/Al2O3, and the catalyst supports IR-120 of the embodiment and the produced catalyst Ru/IR-120. The property analysis is shown in the Exhibit 1. The original color of the catalyst support IR-120 of the embodiment is cream yellow. After reduced by the reducing agent, the surface of the resin chelating with ruthenium ions turns silver white. The photo shot by SEM shows granular ruthenium with nano-structures is formed on the surface of IR-120 after reduction. The average particle size of the reduced ruthenium nano-particles is around 60 nm to 80 nm.
Furthermore, in the test of the catalyst catalyzing the hydrogen releasing reaction, the catalyst Ru/Al2O3 of the control group and the catalyst Ru/IR-120 of the embodiment catalyze the hydrolysis reaction of sodium borohydride and water, for producing hydrogen.
According to the above results, in the manufacturing method of the catalyst Ru/Al2O3, ruthenium chloride solution is produced through impregnation by using γ-Al2O3 as support. The manufacturing method includes calcinations of support, impregnation, filtration and drying, high temperature sintering and reduction through hydrogen. The catalyst Ru/IR-120 of the present embodiment is manufactured by only two steps, chelation and reduction. First, metal ions chelate with the surface of the cation exchange resin. Then, the metal ions are reduced to coating-type catalyst with nano-structures on the surface by the reducing agent. The method avoids the conventional method of performing reduction at a high temperature with plenty of steps. Furthermore, the hydrogen-releasing rate of the catalyst Ru/IR-120 is significantly higher than that of the conventional catalyst Ru/Al2O3.
In the catalyst for catalyzing hydrogen releasing reaction and the manufacturing method thereof provided by the present invention, plenty of metal catalyst ions or nano-scale metal catalysts are formed on the surface of the catalyst supports through chelation and reduction. The advantages include high hydrogen-releasing rate and simplified steps. For example, the catalysts are produced by only two steps, chelating metal ions with the surface of the resin by using cation exchange resin and reducing the metal ions to coating-type catalysts with nano-structures on the surface at room temperature by a reducing agent. Therefore, mass production is achieved rapidly and cheaply without using the conventional high temperature system. As a result, product can be commercialized. Metal catalyst ions are captured on the surface through the chelation of ion exchange resin. Also, the production can be controlled by varying the concentration and time. As to nano-scale metal catalysts, chelation and reduction can be controlled by varying the concentration and time as well for improving the production.
While the invention has been described by way of example and in terms of a preferred embodiment, it is to be understood that the invention is not limited thereto. On the contrary, it is intended to cover various modifications and similar arrangements and procedures, and the scope of the appended claims therefore should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements and procedures.
Number | Date | Country | Kind |
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98108329 | Mar 2009 | TW | national |