Preparation method and application of bimetallic catalyst
阅读说明：本技术 一种双金属催化剂的制备方法及应用 (Preparation method and application of bimetallic catalyst ) 是由 张其坤 张晓旸 赵亚男 束庆香 丁怡 聂付静 贺韵菲 胡泳姣 于 2021-08-09 设计创作，主要内容包括：本公开属于电化学催化合成氨技术领域,具体涉及一种双金属催化剂的制备方法及应用,包括：采用电化学双电极体系,碳棒作为阴极,金属铁作为阳极,以硝酸钴溶液作电解质,进行电化学剥离,得到纳米级的铁；互换电极位置后,进行碳剥离；在双电极剥离完成后,进行共沉淀,离心分离、烘干后得到双金属催化剂。纳米双金属电极用于水体系电化学催化合成氨,得到较高的氨产率和法拉第效率,氨产率可达591.43mg h～(-)～(1)m～(-2),法拉第效率可达33.36％。(The invention belongs to the technical field of electrochemical catalytic synthesis of ammonia, and particularly relates to a preparation method and application of a bimetallic catalyst, which comprises the following steps: adopting an electrochemical double-electrode system, taking a carbon rod as a cathode, taking metallic iron as an anode, taking a cobalt nitrate solution as an electrolyte, and carrying out electrochemical stripping to obtain nanoscale iron; after the electrode positions are interchanged, carbon stripping is carried out; after the double-electrode stripping is finished, coprecipitation is carried out, centrifugal separation is carried out, and the bimetallic catalyst is obtained after drying. The nanometer bimetal electrode is used for electrochemically catalyzing and synthesizing ammonia in a water system to obtain higher ammonia yield and Faraday efficiency, and the ammonia yield can reach 591.43mg h ‑ 1 m ‑2 The Faraday efficiency can reach 33.36%.)
1. A preparation method of a bimetallic catalyst is characterized by comprising the following steps: adopting an electrochemical double-electrode system, taking a carbon rod as a cathode, taking metallic iron as an anode, taking a cobalt nitrate solution as an electrolyte, and carrying out electrochemical stripping to obtain nanoscale iron; after the electrode positions are interchanged, carbon stripping is carried out; after the double-electrode stripping is finished, coprecipitation is carried out, centrifugal separation is carried out, and the bimetallic catalyst is obtained after drying.
2. The method for preparing a bimetallic catalyst as in claim 1, wherein the electrochemical stripping is carried out by a constant voltage method with a voltage set to 1-5V.
3. The process for preparing a bimetallic catalyst as in claim 1 or 2, characterized in that the electrochemical stripping time is 2-5 h; alternatively, the electrochemical peeling is performed at normal temperature and pressure.
4. The process for the preparation of a bimetallic catalyst as in claim 1, characterized in that the concentration of the cobalt nitrate solution is between 0.5 and 5M, preferably 2.0M.
5. The method of claim 1, wherein the centrifugal separation speed is 4000 to 10000 rpm; the temperature of vacuum drying is 50-120 ℃, and the vacuum degree is 10-60 mmHg.
6. A bimetallic catalyst, characterized in that it is obtained by the process according to any one of claims 1 to 5.
7. A bimetallic catalyst electrode for the electrochemical synthesis of ammonia, which is characterized in that the electrode is prepared by mixing the bimetallic catalyst of claim 6 with a binder.
8. The bimetallic catalyst electrode of claim 7, wherein the binder is selected from the group consisting of sodium carboxymethylcellulose (CMC), polyvinylidene fluoride (PVDF), styrene butadiene rubber, and polytetrafluoroethylene; preferably, it is polyvinylidene fluoride (PVDF).
9. A method for electrochemically synthesizing ammonia, characterized in that the electrochemical synthesis ammonia of claim 7 or 8 is carried out by taking a bimetallic catalyst electrode as a working electrode, a Pt electrode as a counter electrode, a calomel electrode as a reference electrode, a potassium phosphate solution as an electrolyte solution and a constant voltage method.
10. The process for the electrochemical synthesis of ammonia according to claim 9, characterized in that the constant voltage method has a voltage of-1.0 to 2.0V; alternatively, the concentration of the potassium phosphate solution is 0.1 to 2.0M, preferably 1.0M.
Technical Field
The disclosure belongs to the technical field of electrochemical catalytic synthesis of ammonia, and particularly relates to a preparation method and application of a bimetallic catalyst.
Background
The information in this background section is only for enhancement of understanding of the general background of the invention and is not necessarily to be construed as an admission or any form of suggestion that this information forms the prior art that is already known to a person of ordinary skill in the art.
Ammonia is an important chemical product, and is a raw material of products such as nitrogen fertilizer, fiber, explosive and the like, and is a non-carbon hydrogen storage medium, a refrigerant fluid and a clean combustion fuel. Currently, the industry is primarily using the Haber-Bosch process, which has a centuries history. The Haber-Bosch process is generally a catalytic synthesis from fossil fuels (coal, petroleum, natural gas, etc.) powered and hydrogen sources using iron-based catalysts at high temperatures (400 ℃ C. -500 ℃ C.) and high pressures (200-. More than 90% of the world's ammonia is reported to be produced industrially by the Haber-Bosch process, which consumes about 3% -5% of the world's natural gas production annually, accounting for about 1% -2% of the world's energy supply; at the same time, about 400Mt of CO is released during the production of ammonia2Accounting for 1.5% of all greenhouse gas emissions. With the increasing global population, the increasing exhaustion of fossil fuels and the increasing awareness of environmental safety, an alternative and sustainable method is developed, and a new green process capable of synthesizing ammonia under mild conditions by using renewable resources rather than fossil fuels is urgently needed.
One of the current research hotspots is the electrochemical catalytic reduction of nitrogen to synthesize ammonia (NRR), and the electrochemical catalytic synthesis of NH3It was reported since 1985. Compared with other nitrogen activation processes, the electrochemical transmission electron has obvious advantages, can break through thermodynamic limitation, enables high-temperature and high-pressure reaction to be realized at normal temperature and normal pressure, and can be used as a power source for non-fossil energy sources such as wind power, water power, solar energy, nuclear energy and the likeThe cost of electric power is low, and the industrialization is easy to be promoted. The nitrogen or air is used as a nitrogen source, and the water is used as a proton source, so that the problems of fossil energy consumption and carbon emission in the H-B process are solved. However, the inventors have found that NH is synthesized electrochemically3In the process, the preparation of the electrode is complex, the performance of the electrode for electrochemically synthesizing ammonia is poor due to poor catalytic effect of the catalyst, the ammonia yield and the Faraday efficiency are low, and the industrial prospect is not to mention. Therefore, how to prepare a catalyst for synthesizing ammonia with better performance and prepare an electrode with better performance by a simple and quick method is very important.
Disclosure of Invention
In order to overcome the problems and limitations of the electrode preparation process in the existing electrochemical ammonia synthesis technology, a preparation method and application of a bimetallic catalyst are provided, wherein a carrier is used for loading a nano bimetallic catalyst, and the prepared electrode is adopted to carry out the technical scheme of electrochemical ammonia synthesis at normal temperature and normal pressure.
Specifically, the technical scheme of the present disclosure is as follows:
in a first aspect of the present disclosure, a method of preparing a bimetallic catalyst comprises: adopting an electrochemical double-electrode system, taking a carbon rod as a cathode, taking metallic iron as an anode, taking a cobalt nitrate solution as an electrolyte, and carrying out electrochemical stripping to obtain nanoscale iron; after the electrode positions are interchanged, carbon stripping is carried out; after the double-electrode stripping is finished, coprecipitation is carried out, centrifugal separation is carried out, and the bimetallic catalyst is obtained after drying.
In a second aspect of the present disclosure, a bimetallic catalyst is obtained by the above-described preparation method.
In a third aspect of the disclosure, a bimetallic catalyst electrode for ammonia electrochemical synthesis is prepared by mixing the bimetallic catalyst and a binder.
In the fourth aspect of the present disclosure, the electrochemical synthesis of ammonia is performed by using the bimetallic catalyst electrode as a working electrode, a Pt electrode as a counter electrode, a calomel electrode as a reference electrode, and a potassium phosphate solution as an electrolyte solution in a constant voltage method.
One or more technical schemes in the disclosure have the following beneficial effects:
(1) the electrode material is prepared by adopting an electrode stripping method, the method is a convenient and efficient method, the prepared material is a nano-scale bimetallic system, can be well enriched on a carrier, has good dispersibility, and can be conveniently prepared into a working electrode by adding a binder into the obtained sample powder and pressing into a tablet.
(2) The nano bimetallic electrode is used for synthesizing ammonia by electrochemical catalysis of a water system, and high ammonia yield and Faraday efficiency can be obtained, wherein the ammonia yield can reach 591.43mg h-1m-2The Faraday efficiency can reach 33.36%.
Drawings
The accompanying drawings, which are included to provide a further understanding of the disclosure, illustrate embodiments of the disclosure and together with the description serve to explain the disclosure and are not to limit the disclosure.
FIG. 1: x-ray diffraction pattern for the catalyst of example 1;
FIG. 2: an X-ray photoelectron spectrum for the catalyst of example 1;
FIG. 3: scanning electron microscope SEM images of the catalyst of example 1;
FIG. 4: is a low power transmission electron microscope TEM image of the catalyst charge of example 1.
Detailed Description
The disclosure is further illustrated with reference to specific examples. It should be understood that these examples are for illustrative purposes only and are not intended to limit the scope of the present disclosure. The experimental procedures, in which specific conditions are not noted in the following examples, are generally carried out according to conventional conditions or according to conditions recommended by the manufacturers.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. The reagents or starting materials used in the present invention can be purchased from conventional sources, and unless otherwise specified, the reagents or starting materials used in the present invention can be used in a conventional manner in the art or in accordance with the product specifications. In addition, any methods and materials similar or equivalent to those described herein can be used in the methods of the present invention. The preferred embodiments and materials described herein are intended to be exemplary only.
It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present disclosure. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of the stated features, steps, operations, and/or combinations thereof, unless the context clearly indicates otherwise.
At present, the existing catalyst for electrochemically synthesizing ammonia has poor catalytic effect, and the preparation method of the electrode for preparing the electrochemically synthesized ammonia is complex, so that the performance of the synthesized ammonia is poor, the ammonia yield and the Faraday efficiency are low, and the industrial application is difficult to realize.
In one embodiment of the present disclosure, a method of preparing a bimetallic catalyst comprises: adopting an electrochemical double-electrode system, taking a carbon rod as a cathode, taking metallic iron as an anode, taking a cobalt nitrate solution as an electrolyte, and carrying out electrochemical stripping to obtain nanoscale iron; after the electrode positions are interchanged, carbon stripping is carried out; after the double-electrode stripping is finished, coprecipitation is carried out, centrifugal separation is carried out, and the bimetallic catalyst is obtained after drying.
In the preparation method, an alkaline solution is added to ensure that cobalt and iron are coprecipitated under the participation of stripping carbon to obtain a mixture. Compared with the existing preparation method of other catalysts, the method adopts an electrochemical stripping method, can conveniently prepare the nano-grade dispersed bimetallic catalyst, can improve the uniform dispersion and controllable preparation of the catalyst, and has better catalytic effect on improving the synthesis of ammonia.
Among them, carbon is required to be involved in the co-precipitation of cobalt and iron in order to obtain a uniform dispersion effect. The reason is that nano-scale particles are easy to agglomerate, carbon participates in coprecipitation, and the agglomeration phenomenon can be effectively inhibited, so that the prepared iron-cobalt nano-particles are uniformly dispersed.
Wherein, the preparation of the cobalt nitrate solution comprises the following steps: weighing Co (NO) of different quality3)2·6H2Adding deionized water into the O solid, stirring until the O solid is dissolved, then fixing the volume, and respectively preparing 0.5-5M Co (NO)3)2And (5) preparing an aqueous solution for later use. Preferably, the concentration of the cobalt nitrate solution is 2.0M. In this step, Co (NO)3)2·6H2The O solid is readily soluble in water and deionized water is used to avoid the effect of other ions in the water on the reaction.
And (3) carrying out electrochemical stripping by adopting a constant voltage method and setting the voltage to be 1-5.0V. Uniform nano-iron can be obtained within the voltage range, agglomeration can be caused by overhigh voltage, and the stripping effect is poor due to overlow voltage.
The time of electrochemical stripping is 2-5.0 h; alternatively, the electrochemical peeling is performed at normal temperature and pressure. The time of electrochemical stripping is optimally 3.0h, and at the moment, the nano iron is uniform and does not agglomerate.
The centrifugal separation rotating speed is 4000-10000 rpm; the temperature of vacuum drying is 50-120 ℃, and the vacuum degree is 10-60 mmHg. During the vacuum drying process, it is necessary to control the temperature, and too high temperature easily causes the material to be oxidized or cracked.
In one embodiment of the present disclosure, a bimetallic catalyst is obtained by the above-described preparation method.
In one embodiment of the disclosure, the bimetallic catalyst electrode for ammonia electrochemical synthesis is prepared by mixing the bimetallic catalyst and a binder. Adding binder, pressing into tablet, trimming into square electrode slice, and clamping on electrode clamp with good conductivity to obtain working electrode. The preparation method is very simple and efficient, and is favorable for exerting the catalytic performance of the catalyst.
The binder is selected from sodium carboxymethylcellulose (CMC), polyvinylidene fluoride (PVDF), styrene butadiene rubber or polytetrafluoroethylene; preferably, it is polyvinylidene fluoride (PVDF).
In one embodiment of the present disclosure, a method for electrochemically synthesizing ammonia is provided, in which a bimetallic catalyst electrode for electrochemically synthesizing ammonia is used as a working electrode, a Pt electrode is used as a counter electrode, a calomel electrode is used as a reference electrode, a potassium phosphate solution is used as an electrolyte solution, and the ammonia is electrochemically synthesized by catalysis in a constant voltage method.
The voltage of the constant voltage method is-1.0-2.0V; or, the concentration of potassium phosphate solution is 0.1-2.0M, preferably 1.0M, under the synthesis conditions, ammonia yield and faraday efficiency can be improved.
In order to make the technical solutions of the present disclosure more clearly understood by those skilled in the art, the technical solutions of the present disclosure will be described in detail below with reference to specific embodiments.
Example 1
Cobalt nitrate hexahydrate (Co (NO) was weighed3)2·6H2O)29.103g, adding a small amount of deionized water, stirring, dissolving, and transferring to a 200ml volumetric flask for later use. The carbon rod is respectively put in ethanol and deionized water for ultrasonic treatment for 30min, and is taken out and then is polished by fine sand paper, so that the surface is rough, and the stripping is facilitated.
Adopting a double-electrode system, taking a metal iron electrode as a counter electrode, taking a carbon rod electrode as a working electrode, and taking 0.5M Co (NO)3)2Putting 120ml of the solution into a 150ml conventional electrolytic cell to be used as an electrolyte solution, and carrying out electrochemical stripping in a Princeton electrochemical workstation by adopting a constant voltage method, wherein the voltage is set to be 5V, the time per point is 0.05s, and the duration is 7200 s; the electrochemical treatment was carried out under the same conditions using a carbon rod electrode as a counter electrode and metallic iron as a working electrode.
After the electrode stripping step is finished, adding an alkaline solution to ensure that the cobalt solution and the iron are coprecipitated under the participation of stripping carbon, carrying out centrifugal separation on the obtained mixture at the rotating speed of 4000rpm, putting the separated precipitate into a vacuum drying oven, and carrying out vacuum drying at the vacuum degree of 40mmHg and the temperature of 60 ℃ for 4 hours. And adding the obtained sample powder into a polytetrafluoroethylene electrode binder for bonding, and finally tabletting and shaping by a tabletting machine. And trimming and polishing the obtained electrode slice into a square with the side length of 1cm, and taking the electrode slice as an electrochemical synthesis ammonia electrode slice.
The prepared bimetallic electrode is used as a working electrode, and a Pt electrode is used as a counter electrodeThe calomel electrode is used as a reference electrode, the potassium phosphate solution with the concentration of 1.0M is used as an electrolyte solution, and an electrochemical catalytic synthesis ammonia performance experiment is carried out by using an electrochemical workstation constant voltage method with the voltage of 1.0V. The ammonia content of the system is detected by indophenol blue spectrophotometry, and the result shows that the ammonia yield of the electro-catalysis synthesis ammonia is 303.6mg h-1m-2The Faraday efficiency reaches 20.4%.
Example 2
Cobalt nitrate hexahydrate (Co (NO) was weighed3)2·6H2O)58.206g, adding a small amount of deionized water, stirring, dissolving, and transferring to a 200ml volumetric flask for later use. The carbon rod is respectively put in ethanol and deionized water for ultrasonic treatment for 30min, and is taken out and then is polished by fine sand paper, so that the surface is rough, and the stripping is facilitated.
Adopting a double-electrode system, taking a metal iron electrode as a counter electrode, taking a carbon rod electrode as a working electrode, and taking 1.0M of Co (NO)3)2Putting 120ml of the solution into a 150ml conventional electrolytic cell to be used as an electrolyte solution, and carrying out electrochemical stripping in a Princeton electrochemical workstation by adopting a constant voltage method, wherein the voltage is set to be 10V, the time per point is 0.05s, and the duration is 7200 s; the electrochemical treatment was carried out under the same conditions using a carbon rod electrode as a counter electrode and metallic iron as a working electrode.
After the electrode stripping is finished, adding an alkaline solution to ensure that the cobalt solution and the iron are coprecipitated under the participation of stripping carbon, carrying out centrifugal separation on the obtained mixture at the rotating speed of 4000rpm, putting the separated precipitate into a vacuum drying oven, and carrying out vacuum drying at the vacuum degree of 40mmHg and the temperature of 60 ℃ for 4 hours. And adding the obtained sample powder into a styrene butadiene rubber electrode binder for bonding, and finally tabletting and shaping by a tabletting machine. And trimming and polishing the obtained electrode slice into a square with the side length of 1cm, and taking the electrode slice as an electrochemical synthesis ammonia electrode slice.
The prepared bimetallic electrode is used as a working electrode, the Pt electrode is used as a counter electrode, the calomel electrode is used as a reference electrode, 2.0M potassium phosphate solution is used as electrolyte solution, and an electrochemical catalytic synthesis ammonia performance experiment is carried out by using an electrochemical workstation constant voltage method with the voltage of 2.0V. Detection system by indophenol blue spectrophotometryThe ammonia content shows that the ammonia yield of the electrocatalytic synthesis ammonia is 286.6mg h-1m-2The Faraday efficiency reaches 18.6%.
Example 3
Cobalt nitrate hexahydrate (Co (NO) was weighed3)2·6H2O)116.412g, adding a small amount of deionized water, stirring, dissolving, and transferring to a 200ml volumetric flask for later use. The carbon rod is respectively put in ethanol and deionized water for ultrasonic treatment for 30min, and is taken out and then is polished by fine sand paper, so that the surface is rough, and the stripping is facilitated.
Adopting a double-electrode system, taking a metal iron electrode as a counter electrode, taking a carbon rod electrode as a working electrode, and taking 2.0M of Co (NO)3)2Putting 120ml of the solution into a 150ml conventional electrolytic cell to be used as an electrolyte solution, and carrying out electrochemical stripping in a Princeton electrochemical workstation by adopting a constant voltage method, wherein the voltage is set to be 5V, the time per point is 0.05s, and the duration is 18000 s; the electrochemical treatment was carried out under the same conditions using a carbon rod electrode as a counter electrode and metallic iron as a working electrode.
After the electrode stripping is finished, adding an alkaline solution to ensure that the cobalt solution and the iron are coprecipitated under the participation of stripping carbon, carrying out centrifugal separation on the obtained mixture at the rotating speed of 4000rpm, putting the separated precipitate into a vacuum drying oven, and carrying out vacuum drying at the vacuum degree of 40mmHg and the temperature of 60 ℃ for 4 hours. And adding the obtained sample powder into a sodium carboxymethylcellulose electrode binder for bonding, and finally tabletting and shaping by a tabletting machine. And trimming and polishing the obtained electrode slice into a square with the side length of 1cm, and taking the electrode slice as an electrochemical synthesis ammonia electrode slice.
The prepared bimetallic electrode is used as a working electrode, the Pt electrode is used as a counter electrode, the calomel electrode is used as a reference electrode, a potassium phosphate solution with the concentration of 1.0M is used as an electrolyte solution, and an electrochemical catalytic synthesis ammonia performance experiment is carried out by using an electrochemical workstation constant voltage method and the voltage of-0.5V. And detecting the ammonia content of the system by indophenol blue spectrophotometry. The results showed that the ammonia yield for the electrocatalytic synthesis of ammonia was 591.43mg h-1m-2The Faraday efficiency reaches 33.36%.
Example 4
Cobalt nitrate hexahydrate (Co (NO) was weighed3)2·6H2O)291.03g, adding a small amount of deionized water, stirring, dissolving, and transferring to a 200ml volumetric flask for later use. The carbon rod is respectively put in ethanol and deionized water for ultrasonic treatment for 30min, and is taken out and then is polished by fine sand paper, so that the surface is rough, and the stripping is facilitated.
Adopting a double-electrode system, taking a metal iron electrode as a counter electrode, taking a carbon rod electrode as a working electrode, and taking 5.0M of Co (NO)3)2Putting 120ml of the solution into a 150ml conventional electrolytic cell to be used as an electrolyte solution, and carrying out electrochemical stripping in a Princeton electrochemical workstation by adopting a constant voltage method, wherein the voltage is set to be 10V, the time per point is 0.05s, and the duration is 18000 s; the electrochemical treatment was carried out under the same conditions using a carbon rod electrode as a counter electrode and metallic iron as a working electrode.
After the electrode stripping is finished, adding an alkaline solution to ensure that the cobalt solution and the iron are coprecipitated under the participation of stripping carbon, carrying out centrifugal separation on the obtained mixture at the rotating speed of 6000rpm, putting the separated precipitate into a vacuum drying oven, and carrying out vacuum drying at the vacuum degree of 50mmHg for 4 hours at the temperature of 80 ℃. And adding the obtained sample powder into a polyvinylidene fluoride (PVDF) electrode binder for bonding, and finally tabletting and shaping by a tabletting machine. And trimming and polishing the obtained electrode slice into a square with the side length of 1cm, and taking the electrode slice as an electrochemical synthesis ammonia electrode slice.
The prepared bimetallic electrode is used as a working electrode, the Pt electrode is used as a counter electrode, the calomel electrode is used as a reference electrode, the potassium phosphate solution with the concentration of 0.1M is used as an electrolyte solution, and an electrochemical catalytic synthesis ammonia performance experiment is carried out by using an electrochemical workstation constant voltage method with the voltage of-1.0V. The ammonia content of the system is detected by indophenol blue spectrophotometry, and the result shows that the ammonia yield of the electro-catalysis synthesis ammonia is 412.8mg h-1m-2The Faraday efficiency reaches 23.7%.
Comparative example 1:
compared with example 1, the difference is that: taking a metal iron electrode as a counter electrode and a carbon rod electrode as a working electrode, directly adding an alkaline solution for coprecipitation without exchanging the positions of the electrodes after electrochemical strippingAnd (4) precipitating. The catalyst is prepared into an electrode plate and then used for electrochemically synthesizing ammonia, and the specific steps are the same as those in example 1. The ammonia content of the system is detected by indophenol blue spectrophotometry, and the result shows that the ammonia yield of the electrocatalytic synthesis ammonia is only 101.6mg h-1m-2The faraday efficiency is only 6.80%.
It can be seen that carbon is required to co-precipitate cobalt and iron. Carbon participates in coprecipitation, so that agglomeration can be effectively inhibited, the prepared iron-cobalt nanoparticles are uniformly dispersed, and the ammonia yield and the Faraday efficiency are obviously improved.
Comparative example 2:
compared with example 1, the difference is that: cobalt nitrate was replaced with nickel nitrate. The catalyst is prepared into an electrode plate and then used for electrochemically synthesizing ammonia, and the specific steps are the same as those in example 1. The ammonia content of the system is detected by indophenol blue spectrophotometry, and the result shows that the ammonia yield of the electrocatalytic synthesis ammonia is only 86.8mg h-1m-2The faraday efficiency is only 5.81%.
Therefore, the iron-cobalt bimetallic catalyst prepared by the method has a synergistic effect, and the cobalt metal is replaced by the nickel metal, so that the catalytic effect is weakened, and the synergistic effect is avoided.
Although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that changes may be made in the embodiments and/or equivalents thereof without departing from the spirit and scope of the invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.