TWI535891B - Hydrogen producing method and system for applying the same - Google Patents

Description

Hydrogen generation method and application system thereof

The technical field disclosed in the present specification relates to a hydrogen gas (H ₂ ) production method and a system using the same. In particular, there is a method for producing hydrogen by electrolysis of water and an application system thereof.

Since the industrial revolution, the amount of carbon dioxide emitted by the world has increased, seriously affecting the ecological environment. In order to reduce carbon dioxide emissions while maintaining energy production for human needs, reducing the use of fossil fuels, increasing the proportion of renewable energy and improving energy efficiency are the goals and trends of national research. Hydrogen energy is a secondary energy source. It is rich in natural resources and can be continuously circulated by regenerative conversion. In the process of releasing energy, it does not produce greenhouse gas output such as carbon dioxide. It has the advantages of low pollution and environmental protection. New energy for development potential.

Hydrogen production by water electrolysis is a relatively mature technology. The electrolytic cell is used to carry the electrolyte, and the alloy or the oxide or the graphite carbon material or the composite material thereof is used as the anode and the cathode electrode. When a voltage is applied by the DC power source, oxygen and hydrogen can be separately generated and collected at the two electrode ends. Since the electrolysis reaction itself is non-spontaneous oxidation In the original reaction, the reaction must be carried out by applying a voltage. In actual operation, the voltage loss caused by the electrode material and the electrolytic cell structure is often caused, so that the electrolysis efficiency is lowered and the power cost is high. How to improve the hydrogen production efficiency of water electrolysis has become a major challenge in the field.

Therefore, there is a need to provide a hydrogen generation method and an application system thereof to solve the problems faced by the prior art.

One embodiment of the invention is directed to a method of producing hydrogen. This hydrogen generation method includes the steps of first providing an acidic electrolytic aqueous solution and an alkaline electrolytic aqueous solution, and isolating the acidic electrolytic aqueous solution and the alkaline electrolytic aqueous solution with an ion exchange membrane. Thereafter, electric power is applied again to cause an electrolysis current to flow from the alkaline electrolytic solution through the ion exchange membrane to the acidic electrolytic aqueous solution to generate hydrogen gas.

Another aspect of the present invention provides a hydrogen generating system comprising a first tank having an acidic electrolytic aqueous solution, a second tank having an alkaline electrolytic aqueous solution, an ion exchange membrane, and a power supply device. Wherein, the ion exchange membrane is located between the first tank body and the second tank body for isolating the acidic electrolytic aqueous solution and the alkaline electrolytic aqueous solution. The power supply device is electrically connected to the alkaline electrolytic aqueous solution and the acidic electrolytic aqueous solution to provide an electrolytic current flowing from the alkaline electrolytic aqueous solution through the ion exchange membrane to the acidic electrolytic aqueous solution.

According to the above, an embodiment of the present invention discloses a novel hydrogen generating method and an application system thereof. Ion exchange membrane is used to isolate acidic electrolytic solution And an alkaline electrolytic aqueous solution, and connecting the positive electrode and the negative electrode of the power supply device to the alkaline electrolytic aqueous solution and the acidic electrolytic aqueous solution, respectively, to form an acidic-alkaline double electrolytic aqueous solution water electrolysis hydrogen production system for performing electrolytic reaction of water, so that The acidic electrolytic aqueous solution of the cathode generates hydrogen gas to generate oxygen in the alkaline electrolytic aqueous solution of the anode.

By the characteristic of the solution potential difference between the acidic electrolytic aqueous solution and the alkaline double electrolytic aqueous solution, the operating voltage required for hydrogen production by hydrogen electrolysis is reduced, and the function of reducing the electric energy consumption to improve the hydrogen generation efficiency is achieved. Since the acid-alkaline double electrolytic aqueous solution water electrolysis hydrogen production system provided by the invention has high water electrolysis activity, compared with the traditional water electrolysis hydrogen production system using pure acidic electrolytic aqueous solution or pure alkaline electrolytic aqueous solution, A low voltage is operated to generate an electrolysis current. That is to say, it is possible to generate an equal amount of hydrogen (or generate a larger amount of hydrogen with the same electric energy consumption) with less power consumption, thereby achieving the purpose of saving power costs and greatly improving competitiveness.

100‧‧‧ Hydrogen generation system

101‧‧‧ first trough

102‧‧‧Second trough

103‧‧‧ acidic electrolytic solution

104‧‧‧Alkaline electrolytic solution

105‧‧‧Ion exchange membrane

106‧‧‧Power supply unit

106a‧‧‧The negative pole of the power supply unit

106b‧‧‧The positive pole of the power supply unit

107‧‧‧First electrode

108‧‧‧second electrode

108a‧‧‧ Surface of the second electrode

109‧‧‧Wire

110‧‧‧Wire

111‧‧‧Water permeable film

112‧‧‧Water supply

113‧‧‧Gas collecting device

114‧‧‧Gas collecting device

S1‧‧‧ provides a hydrogen generation system comprising at least an acidic electrolytic aqueous solution, an alkaline electrolytic aqueous solution, and an ion exchange membrane for isolating the acidic electrolytic aqueous solution and the alkaline electrolytic aqueous solution

S2‧‧‧ Apply electricity, introduce the electrolysis current into the alkaline electrolysis solution, and flow through the ion exchange membrane to the acidic electrolysis solution

R‧‧‧Distance between the first electrode and the second electrode

The above-described embodiments and other objects, features and advantages of the present invention will become more apparent from the embodiments of the invention. A block diagram of a hydrogen generation system illustrated in the embodiment; and a second diagram showing a flow chart of a method for generating hydrogen using the hydrogen generation system illustrated in FIG.

The embodiment disclosed in the present specification relates to a hydrogen generation method and an application system thereof, which can solve the problem that the conventional method of water electrolysis hydrogen production is inefficient and the power cost is high. The above described objects, features, and advantages of the invention will be apparent from the description of the appended claims.

However, it must be noted that these specific embodiments and methods are not intended to limit the invention. The invention may be practiced with other features, elements, methods and parameters. The preferred embodiments are merely illustrative of the technical features of the present invention and are not intended to limit the scope of the invention. Equivalent modifications and variations will be made without departing from the spirit and scope of the invention. In the different embodiments and the drawings, the same elements will be denoted by the same reference numerals.

FIG. 1 is a block diagram of a hydrogen generating system 100 according to an embodiment of the invention. The hydrogen generation system 100 includes a first tank body 101, a second tank body 102, an acidic electrolytic solution 103, an alkaline electrolytic solution 104, an ion exchange membrane 105, and a power supply device 106. The acidic electrolytic solution 103 is carried in the first tank 101; the alkaline electrolytic solution 104 is carried in the second tank 102; the ion exchange membrane 105 is located between the first tank 101 and the second tank 102. It is used to isolate the acidic electrolytic aqueous solution 103 and the alkaline electrolytic aqueous solution 104. The power supply device 106 is electrically connected to the alkaline electrolytic aqueous solution 104 and the acidic electrolytic aqueous solution 103.

In some embodiments of the present invention, the pH of the acidic aqueous electrolytic solution 103 is substantially between 0 and 5, preferably less than 3; and the pH of the alkaline electrolytic aqueous solution 104 is substantially between 9 and 14, If the ratio is greater than 11, a potential difference of 0.1 V to 1 V may be generated between the acidic electrolytic solution 103 and the alkaline electrolytic solution 104, and a preferred potential difference between the acidic electrolytic solution 103 and the alkaline electrolytic solution 104 is substantially Between 0.7 and 0.8V. For example, in some embodiments of the present invention, the acidic electrolytic aqueous solution 101 may include, but is not limited to, an aqueous solution of sulfuric acid (H ₂ SO ₄ ), an aqueous solution of nitric acid (HNO ₃ ), an aqueous solution of hydrochloric acid (HCl), or a combination of the above aqueous solutions. The alkaline electrolytic aqueous solution may include, but is not limited to, sodium hydroxide (NaOH), potassium hydroxide (KOH) aqueous solution or a combination of the above aqueous solutions.

In some embodiments of the present invention, the potential difference between the acidic electrolytic aqueous solution 103 and the alkaline electrolytic aqueous solution 104 is preferably 0.7V to 0.8V. Here, the potential difference between the acidic electrolytic solution 103 and the alkaline electrolytic solution 104 can be achieved by adjusting the pH or concentration difference between the two. In the present embodiment, the acidic electrolytic aqueous solution 103 may be an aqueous sulfuric acid solution having a concentration of substantially 1 M; and the alkaline electrolytic aqueous solution 104 may be an aqueous sodium hydroxide solution having a concentration of substantially 1.5 M.

Further, in order to increase the efficiency of hydrogen production by electrolysis of water, a plurality of different electropromotors or buffers may be added to the acidic electrolytic aqueous solution 103 and the alkaline electrolytic aqueous solution 104. In some embodiments of the present invention, the electrolytic improver or buffer may include an acid ionic compound of the acidic electrolytic aqueous solution 103, a Lewis base compound of the acidic electrolytic aqueous solution 103, or a combination thereof. For example, the electrolytic improver or buffer may be potassium sulfate (K ₂ SO ₄ ), potassium nitrate (KNO ₃ ), disodium hydrogen phosphate (Na ₂ HPO ₄ ), dipotassium hydrogen phosphate (K ₂ HPO ₄ ) or the like. combination. The method of adding the electrolytic improver or the buffer may be added in an equal amount to the acidic electrolytic aqueous solution 103 and the alkaline electrolytic aqueous solution 104, or may be added in an unequal amount. It may be added only to one of the acidic electrolytic solution 103 and the alkaline electrolytic solution 104. In the examples of the present invention, an electrolytic promoter or a buffer is added in an equal amount to the acidic electrolytic solution 103 and the alkaline electrolytic solution 104, respectively.

The ion exchange membrane 105 that isolates the acidic electrolytic aqueous solution 103 and the alkaline electrolytic aqueous solution 104 may be a proton exchange membrane that allows passage of protons (H ⁺ ) while providing a proton channel between the acidic electrolytic aqueous solution 103 and the alkaline electrolytic aqueous solution 104 ( Proton exchange membranes (PEM) or a filter paper. For example, in some embodiments of the present invention, the ion exchange membrane 105, may be NAFION ^® 117 or 212 or 211 film or NAFION ^TM 450 film by the Sigma-Aldrich ^TM company provided by DuPont (DuPont ^TM) provided by the company, or is a P-5 filter paper Fisherbrand ^TM provided by the company. It is to be noted, however, that the proton exchange membrane and the filter paper described above are merely illustrative, and any isolation structure that can achieve the ion exchange function does not depart from the spirit of the invention.

The power supply device 106 is electrically connected to the acidic electrolytic solution 103 and the alkaline electrolytic solution 104 by the first electrode 107 and the second electrode 108, respectively. For example, in an embodiment of the invention, one end of the first electrode 107 extends into the first tank body 101 and is in contact with the acidic electrolytic solution 103; the other end is electrically connected to the anode 106a of the power supply device 106 via the wire 109. . One end of the second electrode 108 extends into the second tank body 102, and is combined with the alkaline electrolytic aqueous solution 104. The other end is electrically connected to the positive electrode 106b of the power supply device 106 via the wire 110.

The electrolysis current supplied from the power supply device 106 can be introduced into the alkaline electrolytic aqueous solution 104 via the wire 110 and the second electrode 108, through the ion exchange membrane 105 to the acidic electrolytic aqueous solution 103, and the first electrode 107 and the wire 109 are returned. A loop is formed to the power supply unit 106.

The material constituting the first electrode 107 includes platinum (Pt), titanium (Ti), carbon (C) or graphite; the material constituting the second electrode 108 includes platinum (Pt), titanium (Ti), stainless steel, oxidation.铱 (IrO ₂ ) or ruthenium oxide (RuO ₄ ). In the present embodiment, the first electrode 107 is composed of a platinum disc having a diameter of substantially 20 mm and a thickness of substantially 0.3 mm; the second electrode 108 is made of a platinum disc having a diameter of substantially 20 mm and a thickness of substantially 0.3 mm. Composition; or both can be composed of a platinum wire having a diameter of substantially 0.3 mm and a length of substantially 40 cm. Either or both can be composed of a titanium mesh having a mesh size of 1 mm. It is to be noted, however, that the shape and size of the first electrode 107 and the second electrode 108 may vary depending on the materials being constructed and the design of the other components of the hydrogen generating system 100. In other embodiments of the present invention, the shape and size of the first electrode 107 and the second electrode 108 are not limited in any way.

In addition, a water permeable film 111 may be selectively attached to the surface 108a of the second electrode 108 to isolate the hydroxide ions in the alkaline electrolytic solution 104, thereby preventing the hydroxide ion concentration from decreasing with the reaction time to maintain the electrolysis current. Size, improve the stability of the electrolysis operation. In an embodiment of the invention, the layer is permeable The film 111 may be a PTFE filter film (JHWP14225, Omnipore Membrane Filter).

In order to maintain the alkaline electrolytic solution 104 in a uniform concentration in the electrolysis reaction, the hydrogen generating system 100 preferably further includes a water supply device 112 connected to the second tank 102. For example, the water supply device 112 can include a concentration detecting element (not shown), and a water supply line. The concentration detecting component can detect the concentration of the alkaline electrolytic solution 104 in the second tank 102, and provide the second tank 102 with a uniform concentration of the alkaline electrolytic solution 104 by the water supply pipeline according to the detection result. water.

2 is a flow chart showing a method of generating hydrogen by applying the hydrogen generating system 100 illustrated in FIG. The method for generating hydrogen gas by the hydrogen generating system 100 includes the following steps: First, referring to step S1, the hydrogen generating system 100 as shown in FIG. 1 is provided to include at least an acidic electrolytic aqueous solution 103 and an alkaline electrolytic aqueous solution. 104 and an ion exchange membrane 105 for isolating the acidic electrolytic aqueous solution 103 and the alkaline electrolytic aqueous solution 104. Thereafter, electric power is applied, and the electrolysis current supplied from the power supply device 106 is introduced into the alkaline electrolytic aqueous solution 104, and flows through the ion exchange membrane 105 to the acidic electrolytic aqueous solution 103 (as shown in step S2).

In some embodiments of the invention, the operating voltage applied between the first electrode 107 and the second electrode 108 may be substantially between 0.6V and 3V, preferably substantially between 0.6V and 1.4V. The operating temperature can be maintained between substantially 25 ° C and 90 ° C and the pressure in the first tank 101 and the second tank 102 is maintained at a substantial margin between 1 atm and 100 atm. In this embodiment, the operating temperature is preferably maintained at greater than 70 ° C; the pressure in the first tank 101 and the second tank 102 The force is preferably maintained at 1 atm or more.

After the application of the electric power, the generated hydrogen and oxygen can be collected by the drainage gas collection method, and discharged from the first tank body 101 and the second tank body 102 by the gas collecting devices 113 and 114, for example, gas pumping, respectively. .

In addition, the distance between the first electrode 107 and the second electrode 108 is related to the operational stability of the hydrogen generation system 100. In some embodiments of the invention, the distance R between the first electrode 107 and the second electrode 108 is preferably between substantially 0.02 mm and 4 mm. In the present embodiment, the distance R between the first electrode 107 and the second electrode 108 is substantially 0.2 to 0.4 mm.

In order to verify the aforementioned hydrogen generation method and the technical advantages of the hydrogen generation system 100 to which the method is applied, a preferred embodiment (Example 1) is exemplified below, and a 1 M aqueous sulfuric acid solution is disposed as the acidic electrolytic solution 103 of the hydrogen generation system 100. A 1.5 M aqueous sodium hydroxide solution was placed as the alkaline electrolytic aqueous solution 104 of the hydrogen generation system 100, and electrolysis was performed at different voltages to produce hydrogen. At the same time, the water electrolysis hydrogen production system (using 1M sulfuric acid aqueous solution as the electrolyte) using the all-acid electrolyte is used as a comparative example, and the electrolysis current and the hydrogen production amount are compared.

The voltage applied to the hydrogen generating system 100 of the first embodiment and the power consumption (kWh/kg H2) required to generate hydrogen per kilogram are detailed in Table 1:

The voltages applied to the comparative examples, as well as the energy consumption required per kilogram of hydrogen, are detailed in Table 2:

Comparing the experimental results of the first embodiment and the comparative example, it is apparent that the hydrogen generating system 100 provided by the present invention can perform water decomposition at a lower operating voltage (<1.8 V) to generate hydrogen gas. For example, at an operating voltage of 1.2 V, the power consumption per kilogram of hydrogen produced is approximately 30 kilowatt hours (kWh/kg H ₂ ). Compared to the conventional water electrolysis hydrogen production system using an all-acid electrolyte, the electric power consumption per kilogram of hydrogen is about 59 kWh at an operating voltage of 2.2V. The power consumption of the hydrogen generating system 100 provided by the present invention is only about half of that of a conventional water electrolysis hydrogen producing system using an all-acid electrolyte. That is, the hydrogen generation system 100 provided by the present invention is used for water decomposition to generate hydrogen gas, which can reduce the electric energy cost by about 50%. In other words, if the same electrical energy is consumed, the hydrogen generating system 100 provided by the present invention can generate twice as much hydrogen as the conventional water electrolysis hydrogen producing system using an all-acid electrolyte.

In addition, the hydrogen production system 100 of Comparative Example 1 and the conventional water electrolysis hydrogen production system using an all-acid electrolyte were used before voltage application. The measured open circuit voltage (OCV), that is, the potential difference between the first electrode 107 and the second electrode 108. The hydrogen generating system 100 has an open circuit voltage of up to about 0.8V. In contrast, the open circuit voltage of a water electrolysis hydrogen production system using an all-acid electrolyte is less than 0.1V. It is shown that the acidic electrolytic solution 103 of the hydrogen generating system 100 and the alkaline electrolytic aqueous solution 104 have a higher potential difference than the conventional all-acid electrolyte, which is advantageous for reducing the operating voltage required for water electrolysis to produce hydrogen, thereby reducing energy consumption and increasing production. The function of hydrogen efficiency.

According to the above, an embodiment of the present invention discloses a novel hydrogen generating method and an application system thereof. The ion exchange membrane 105 is used to isolate the acidic electrolytic aqueous solution 103 and the alkaline electrolytic aqueous solution 104, and the positive electrode 106b and the negative electrode 106a of the power supply device 106 are connected to the alkaline electrolytic aqueous solution 104 and the acidic electrolytic aqueous solution 103, respectively, to form an acidic-alkaline double. The water electrolysis hydrogen production system (hydrogen generation system 100) of the electrolytic aqueous solution is subjected to an electrolytic reaction of water to generate hydrogen gas in the acidic electrolytic aqueous solution 103 of the cathode to generate oxygen in the alkaline electrolytic aqueous solution 104 of the anode.

By having the characteristic of the solution potential difference between the acidic electrolytic aqueous solution and the alkaline electrolytic aqueous solution, the operating voltage required for hydrogen production by hydrogen electrolysis is reduced, and the function of reducing the electric energy consumption to improve the hydrogen generation efficiency is achieved. Since the acid-alkaline double electrolytic aqueous solution water electrolysis hydrogen production system provided by the invention has high water electrolysis activity, compared with the traditional water electrolysis hydrogen production system using pure acidic electrolytic aqueous solution or pure alkaline electrolytic aqueous solution, A low voltage is operated to generate an electrolysis current. In other words, it is possible to generate an equal amount of hydrogen (or generate a larger amount of hydrogen with the same power consumption) with less power consumption, thereby saving power costs and greatly improving competitiveness. of.

In conclusion, the present invention has been disclosed in the above preferred embodiments, and is not intended to limit the present invention. A person skilled in the art can make various changes and modifications without departing from the spirit and scope of the invention. Therefore, the scope of the invention is defined by the scope of the appended claims.

100‧‧‧ Hydrogen generation system

101‧‧‧ first trough

102‧‧‧Second trough

103‧‧‧ acidic electrolytic solution

104‧‧‧Alkaline electrolytic solution

105‧‧‧Ion exchange membrane

106‧‧‧Power supply unit

106a‧‧‧The negative pole of the power supply unit

106b‧‧‧The positive pole of the power supply unit

107‧‧‧First electrode

108‧‧‧second electrode

108a‧‧‧ Surface of the second electrode

109‧‧‧Wire

110‧‧‧Wire

111‧‧‧Water permeable film

112‧‧‧Water supply

113‧‧‧Gas collecting device

114‧‧‧Gas collecting device

R‧‧‧Distance between the first electrode and the second electrode

Claims (17)

A hydrogen gas (H ₂ ) production method comprising: providing an acidic electrolytic aqueous solution and an alkaline electrolytic aqueous solution, wherein the acidic electrolytic aqueous solution and the alkaline electrolytic aqueous solution have a potential difference of substantially 0.1 V to 1 V Providing an ion exchange membrane for isolating the acidic electrolytic aqueous solution and the alkaline electrolytic aqueous solution; and applying an operating voltage substantially between 0.6V and 1.4V to cause an electrolytic current to flow through the ion from the alkaline electrolytic aqueous solution The membrane is exchanged to the acidic aqueous electrolytic solution to produce hydrogen. The hydrogen generating method according to claim 1, wherein the acidic electrolytic aqueous solution has a pH substantially less than 3, and the alkaline electrolytic aqueous solution has a pH substantially greater than 11. The hydrogen generating method according to claim 1, wherein the acidic electrolytic aqueous solution comprises sulfuric acid (H ₂ SO ₄ ), nitric acid (HNO ₃ ), hydrochloric acid (HCl), or a combination thereof; the alkaline electrolytic aqueous solution includes Sodium hydroxide (NaOH), potassium hydroxide (KOH) or a combination of the above. The method for producing hydrogen according to claim 1, wherein the step of providing the acidic aqueous electrolytic solution and the alkaline electrolytic aqueous solution further comprises separately The acidic electrolytic aqueous solution and the alkaline electrolytic aqueous solution provide an electroproator; wherein the electrolytic promoter comprises an acid ionic compound of the acidic electrolytic aqueous solution, and a Lewis base compound opposite to the acidic electrolytic aqueous solution. Or a combination of the above. The method for producing hydrogen according to claim 1, wherein the step of applying the operating voltage comprises: providing a first electrode in contact with the acidic electrolytic aqueous solution, and providing a second electrode in contact with the alkaline electrolytic aqueous solution; The first electrode is electrically connected to a negative electrode of a power supply device; and the second electrode is electrically connected to a positive electrode of the power supply device. The method of applying the operating voltage according to the method of claim 1, wherein the step of applying the operating voltage further comprises attaching a water permeable film to the surface of the second electrode to isolate hydroxide ions in the alkaline electrolytic aqueous solution. The hydrogen generating method according to claim 5, further comprising maintaining an operating temperature substantially between 25 ° C and 90 ° C and a pressure substantially between 1 atm and 100 atm. A hydrogen generating system comprising: a first tank body having an acidic electrolytic aqueous solution; and a second tank body having an alkaline electrolytic aqueous solution, wherein the acidic electrolytic aqueous solution and the alkaline electrolytic aqueous solution have a substantial boundary between 0.1 a potential difference of V to 1V; an ion exchange membrane between the first tank and the second tank to isolate the acidic electrolytic aqueous solution and the alkaline electrolytic aqueous solution; and a power supply device electrically connected to the An alkaline electrolytic aqueous solution and the acidic electrolytic aqueous solution for applying an operating voltage substantially between 0.6V and 1.4V to provide an electrolysis current from the alkaline electrolytic aqueous solution flowing through the ion exchange membrane to the acidic electrolytic aqueous solution . The hydrogen generating system according to claim 8, wherein the acidic electrolytic aqueous solution has a pH substantially less than 3, and the alkaline electrolytic aqueous solution has a pH substantially greater than 11. The hydrogen generating system according to claim 9, wherein the acidic electrolytic aqueous solution comprises sulfuric acid, nitric acid, hydrochloric acid, or a combination thereof; and the alkaline electrolytic aqueous solution comprises sodium hydroxide, potassium hydroxide or a combination thereof. The hydrogen generating system of claim 8, wherein the acidic electrolytic aqueous solution and the alkaline electrolytic aqueous solution respectively comprise an electrolysis enhancement The electrolytic improver comprises an acid ionic compound of the acidic electrolytic aqueous solution, a Lewis base compound as opposed to the acidic electrolytic aqueous solution or a combination thereof. The hydrogen generating system of claim 8, further comprising: a first electrode, one end is in contact with the acidic electrolytic aqueous solution, the other end is electrically connected to a negative electrode of the power supply device; and a second electrode is One end is in contact with the alkaline electrolytic aqueous solution, and the other end is electrically connected to a positive electrode of the power supply device. The hydrogen generating system according to claim 12, further comprising a water permeable film attached to a surface of the second electrode to isolate hydroxide ions in the alkaline electrolytic aqueous solution. The hydrogen generating system of claim 12, wherein the first electrode and the second electrode have a distance substantially between 0.02 mm and 4 mm. The hydrogen generating system according to claim 12, wherein the material constituting the first electrode comprises platinum (Pt), titanium (Ti), carbon (C) or graphite. The hydrogen generating system according to claim 12, wherein the material constituting the second electrode comprises platinum (Pt), titanium (Ti), stainless steel, cerium oxide (IrO ₂ ) or cerium oxide (RuO). ₄ ). The hydrogen generating system of claim 8, further comprising a water supply device connected to the second tank for maintaining a concentration of the alkaline electrolytic aqueous solution.