CN112251765B

CN112251765B - Water-splitting hydrogen production device based on lead net and preparation method and use method thereof

Info

Publication number: CN112251765B
Application number: CN202011188670.2A
Authority: CN
Inventors: 康帅; 陆文强; 薛凤娟; 付勰; 王亮; 冯双龙
Original assignee: Chongqing Institute of Green and Intelligent Technology of CAS
Current assignee: Chongqing Institute of Green and Intelligent Technology of CAS
Priority date: 2020-10-30
Filing date: 2020-10-30
Publication date: 2023-08-22
Anticipated expiration: 2040-10-30
Also published as: CN112251765A

Abstract

The invention discloses a lead mesh-based water-splitting hydrogen production device, a preparation method and a use method thereof. The invention provides a method for preparing an anode of a high-efficiency PEM hydrolysis device by using non-noble metals, which has simple system structure and low price; and the anode based on the lead net can stabilize electrochemical hydrolysis reaction under acidic and high temperature (above 60 ℃).

Description

Water-splitting hydrogen production device based on lead net and preparation method and use method thereof

Technical Field

The invention belongs to the technical field of power supplies, and particularly relates to a lead-net-based water-splitting hydrogen production device, a preparation method and a use method thereof.

Background

Hydrogen is the highest energy density material, up to 33.3 kWh/kg, and is used as a secondary energy carrier, for example, as rocket fuel. Hydrogen is widely present in hydrocarbons and water, and is one of the most abundant elements on earth. In contrast to the large amount of hydrogen produced as a byproduct during fossil energy reforming, the hydrogen production by water electrolysis is negligible. Clean energy sources such as wind energy and solar energy can be hydrolyzed by electrochemical reaction to prepare high-purity hydrogen, so that the hydrogen production technology is very hot. At present, the alkaline hydrolysis device is mainly used for producing hydrogen, however, the acidic Proton Exchange Membrane (PEM) hydrolysis device has the advantages of quick reaction, energy conservation, high integration and the like, and therefore, the alkaline hydrolysis device is also paid attention to.

Electrodes currently suitable for use in PEM hydrolyzer applications are mainly noble metal electrodes such as platinum, platinum oxide or platinum alloys as cathodes and ruthenium, rubidium or oxides, alloys thereof as anodes. The low precious metal reserves and the high price cause the extremely high cost of the PEM hydrolyzer. Whereas non-noble metal materials or compounds thereof, particularly transition metal materials or compounds thereof, are extremely unstable in acidity and rapidly decay in hydrogen production efficiency during the hydrolysis process.

Disclosure of Invention

Based on the problems existing in the prior art, the invention provides a water-splitting hydrogen production device based on a lead net, and a preparation method and a use method thereof. In the invention, the stable hydrolysis hydrogen production process at the high temperature of 60 ℃ can be realized without noble metal, the hydrogen production efficiency is improved, and the cost is reduced.

According to a first aspect of the present invention, a lead mesh-based water splitting hydrogen production device is provided, which comprises an anode, a cathode and a diaphragm, wherein the lead mesh covered by a lead mesh or a lead oxide sheet is used as the anode, a hot-pressed platinum carbon PEM or a platinum-plated lead mesh or a titanium mesh or an alloy mesh is used as the cathode, and the PEM is used as the diaphragm.

Wherein, the anode, the diaphragm and the cathode are sequentially overlapped to form a main body of the water decomposition hydrogen production device. And the extending section of the anode and the extending section of the cathode are respectively provided with a direct current power supply interface.

Preferably, the Proton Exchange Membrane (PEM) is a perfluorosulfonic acid type proton exchange membrane, nafion recast membrane, non-fluoropolymer proton exchange membrane, or a novel composite proton exchange membrane. The anode is made of grid materials, and is made of lead metal, alloy or a composite metal net plated with platinum, titanium, zinc oxide and titanium oxide.

According to a second aspect of the technical solution of the present invention, a method for preparing a hydrogen production plant by water splitting based on a lead net is proposed, said method comprising the following steps.

Step 1, preparing an anode lead net; and purchasing the lead foil, and perforating the lead foil by using a perforating machine or a laser engraving machine to prepare a lead net to be used as an anode.

And 2, preparing a cathode, and plating a layer of nano platinum on the lead foil by using a sputtering coating machine to directly serve as the cathode.

And 3, separating the proton exchange membrane between the anode and the cathode, and clamping the anode-diaphragm-cathode by using a shell protection layer and a fixing clamp to prepare the lead-net-based water-splitting hydrogen production device.

Further, the step 1 is to use a sputtering coating machine to plate a layer of nano platinum on the lead foil to be directly used as an anode.

Further, in the step 1, the lead mesh is placed in a polytetrafluoroethylene cup filled with concentrated ammonia water, and the mixture is reacted at a high temperature and a high pressure of 180 ℃ for 6 hours to 72 hours, and a layer of lead oxide sheet is grown on the lead mesh to serve as an anode.

Further, step 2 directly produces a platinum carbon Proton Exchange Membrane (PEM) membrane for a PEM fuel cell anode as a cathode and membrane for a hydrogen plant.

According to a third aspect of the technical scheme of the invention, a use method of a lead-net-based water-splitting hydrogen production device is provided, and the method comprises the following steps.

Step 1, connecting a direct current power supply interface with a direct current power supply, connecting an anode with a positive electrode of the power supply, and connecting a cathode with a negative electrode of the power supply.

And 2, placing the lead-net-based water-splitting hydrogen production device in an acidic aqueous solution, and arranging a direct-current power interface on the liquid level to avoid the contact of the circuit and the aqueous solution.

And step 3, turning on a power switch, starting from 2V, slowly increasing the voltage, and adjusting to a proper voltage according to the hydrogen demand, wherein if the hydrogen demand is large, the voltage is high, and if the hydrogen demand is small, the voltage is low.

And 4, after the gas preparation is finished, firstly adjusting the direct-current power supply to low voltage, then closing the direct-current power supply, and finally disconnecting the direct-current power supply interface from the direct-current power supply.

Compared with the prior art, the invention has the following beneficial effects.

First, the invention provides a method for preparing the anode of the high-efficiency PEM hydrolysis device by using non-noble metals, and the system has simple structure and low cost.

Secondly, the anode based on the lead mesh provided by the invention can be stable in electrochemical hydrolysis reaction at an acidic state and a high temperature (above 60 ℃).

Drawings

Fig. 1 is a schematic diagram of a lead mesh-based water splitting hydrogen plant in accordance with the present invention.

Fig. 2 is a schematic structural view of an anode according to the present invention.

Fig. 3-1 is a schematic structural view of a cathode according to the present invention.

Fig. 3-2 is a schematic diagram of a film forming process according to the present invention.

Fig. 4-1 is a photograph of an anode according to the present invention.

Fig. 4-2 is a scanning electron microscope image according to the present invention.

Fig. 5 is a hydrolysis performance curve of an anode according to the present invention.

FIG. 6 is a graph of hydrogen plant performance according to the present invention.

Wherein the reference numerals: "1" indicates "anode", "2" indicates "cathode", "3" indicates "PEM", "4" indicates "dc power interface".

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. It will be apparent that the described embodiments are only some, but not all, embodiments of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention. Additionally, the scope of the invention should not be limited to the specific experimental methods or specific parameters described below.

The invention designs a water-splitting hydrogen production device based on a lead net based on the stability of lead-based materials in acidity, wherein the lead net covered by a lead net or a lead oxide sheet is used as an anode, a hot-pressed platinum carbon PEM or a platinum-plated lead net (titanium net or alloy net) is used as a cathode, and the PEM is used as a diaphragm. The invention can also grow a low-dimensional lead oxide sheet on the lead metal grid by processing the lead metal grid, and can be used as an anode of a PEM hydrolysis device, thereby achieving the aim of stably hydrolyzing and producing hydrogen at a high temperature of 60 ℃, improving the hydrogen production efficiency and reducing the cost. Noble metals are not used in the present invention.

The lead-net-based water-splitting hydrogen production device shown in fig. 1 comprises an anode 1, a cathode 2 and a diaphragm 3, wherein the diaphragm is preferably a PEM, a water-splitting hydrogen production device body is formed by sequentially stacking the anode 1, the diaphragm 3 and the cathode 2, and a direct-current power supply interface 4 is respectively arranged at an extension section of the anode 1 and an extension section of the cathode 2. In the hydrogen production process, a direct current power supply is connected with the device through a direct current power supply interface 4, electrons flowing out of the negative electrode of the power supply flow into electrolyte through a cathode 2, meanwhile, reduction reaction occurs on the surface of the cathode, and hydrogen ions of the electrolyte near the cathode obtain electrons to generate hydrogen; holes flowing out of the positive electrode of the power supply flow into the electrolyte through the anode 1, meanwhile, oxidation reaction occurs on the surface of the anode electrode, and hydroxide ions in the electrolyte near the anode lose electrons to generate oxygen. In addition, during the hydrogen production process, electrons in the power supply flow into the electrolyte through the cathode 2, generating hydrogen gas at the cathode electrode surface.

The chemical reaction formula is as follows.

Anode: 2H (H) ₂ O=O ₂ ↑+4H ⁺ +4e-

And (3) cathode: 4H (4H) ⁺ +4e-=2H ₂ ↑

General reaction formula: 2H (H) ₂ O = H ₂ ↑+O ₂ ↑

The gas yield is proportional to the current according to faraday's law of electrolysis.

The PEM (proton exchange membrane) as a membrane is preferably a proton exchange membrane satisfying the following conditions: good proton conductivity, small electro-osmosis action of water molecules in the membrane, small permeability of gas in the membrane, good electrochemical stability, good dry-wet conversion performance, certain mechanical strength and good processability. Proton Exchange Membranes (PEM) differ from membranes used in common chemical power supplies, with perfluorosulfonic acid type proton exchange membranes, nafion recast membranes, non-fluoropolymer proton exchange membranes, novel composite proton exchange membranes, and the like being recommended. In the present invention, the cathode and anode are separated by a PEM to avoid direct electron transport by anode-to-cathode contact.

In the lead-net-based water-splitting hydrogen production device, the direct-current power interface 4 generates 1.5-V-5V direct-current voltage.

As shown in FIG. 2, the anode is made of a mesh material, preferably a lead metal, alloy or a composite metal mesh (as shown in FIG. 2) plated with other materials (such as platinum, titanium, zinc oxide, titanium oxide, etc.). The size of the pole piece is positively related to the hydrogen demand, namely, the larger the pole piece is, the more hydrogen is prepared under the same voltage/current in unit time. During operation, electrons in the electrolyte flow through the electrode into the power supply, generating oxygen at the electrode surface. The microscopic part of the anode is preferably a layered structure with lead oxide flakes grown in situ (as in fig. 2 below). The grid morphology increases the electrochemical reaction area on one hand, and is beneficial to the preparation of gas; on the other hand, the pore canal is beneficial to the diffusion of the gas.

As in the cathode structure shown in fig. 3-1, the cathode primary active material is platinum metal. The cathode structure can be preferably in a grid shape, such as a platinum metal is plated on a lead net, a titanium net or an alloy net as shown in fig. 3-1, and the grid shape increases the electrochemical reaction area on one hand, so that the preparation of gas is facilitated; on the other hand, the pore canal is beneficial to the diffusion of the gas. Platinum carbon powder catalysts may also be hot pressed onto the PEM (proton exchange membrane). Through the film-making process shown in fig. 3-2, platinum particles of 2 to 5 nanometers are loaded on activated carbon particles of 10 to 80 nanometers through a platinum-carbon catalyst, so that the utilization rate of platinum is increased. The size of the pole piece is positively related to the hydrogen demand, namely, the larger the pole piece is, the more hydrogen is prepared under the same voltage/current in unit time.

As shown in the photograph of the anode shown in FIG. 4-1 and the scanning electron microscope image shown in FIG. 4-2, the net structure in FIG. 4-1 is obviously seen, which is beneficial to the removal of gas generated by the electrolysis of water, thereby increasing the hydrogen production efficiency. The lead oxide sheet on the surface of the lead mesh on the microstructure can be obviously seen, the electrolytic water area can be greatly increased, and the reaction is promoted.

As can be seen from the hydrolysis performance curve of the anode shown in FIG. 5, the counter electrode Ag/AgCl was used, the electrolyte was 0.5M sulfuric acid, and the electrode area was 1 cm ² . FIG. 6 is a graph of hydrogen plant performance at 60℃with electrolyte 0.5M sulfuric acid; the anode is a lead net, and the electrode area is 1 cm ² The method comprises the steps of carrying out a first treatment on the surface of the The cathode is a platinum sheet, the electrode area is 0.7 cm ² It can be seen that the hydrogen plant was running steadily with little significant decay within 8 hours.

The invention relates to a preparation method of a lead-net-based water-splitting hydrogen production device.

And step 1, preparing an anode lead net. Purchasing lead foil, and perforating the lead foil by using a perforating machine or a laser engraving machine to prepare a lead net; or directly purchasing a lead net; the lead mesh can be used directly as an anode.

The nano platinum can be directly used as an anode by plating a layer of nano platinum on the lead net by using a sputtering coating machine.

The lead net can also be placed in a polytetrafluoroethylene cup filled with strong ammonia water, and a layer of lead oxide sheet is grown on the lead net to be used as an anode after the reaction is carried out for 6 to 72 hours at the high temperature and the high pressure of 180 ℃.

And 2, preparing a cathode. And plating a layer of nano platinum on the lead foil by using a sputtering coating machine to directly serve as a cathode.

The platinum carbon Proton Exchange Membrane (PEM) membrane for the anode of a PEM fuel cell can also be directly manufactured as a cathode and a membrane of a hydrogen production device.

A method for using a lead-net-based water splitting hydrogen production device, which comprises the following steps.

Step 1, connecting a direct current power supply interface 4 with a direct current power supply, connecting an anode 1 with a positive electrode of the power supply, and connecting a cathode 2 with a negative electrode of the power supply.

And 2, placing the lead-net-based water-splitting hydrogen production device in an acidic aqueous solution, and arranging a direct-current power interface 4 on the liquid surface to avoid the contact of a circuit with the aqueous solution.

And 4, after the gas preparation is finished, firstly adjusting the direct-current power supply to low voltage, then closing the direct-current power supply, and finally disconnecting the direct-current power supply interface 4 from the direct-current power supply.

The lead-net-based water-splitting hydrogen production device is designed, and the device can stably operate in acidity at high temperature without obvious degradation; the invention can be applied to an electrocatalytic water-splitting hydrogen production system; a fuel cell system; preparing chlorine by electrocatalytic; and (3) catalytic oxidation of small organic molecules. It should also be noted that the shapes and dimensions of the various components in the figures do not reflect the actual sizes and proportions, but merely illustrate the contents of the embodiments of the present invention.

The present invention is not described in detail in part as being well known to those skilled in the art. The foregoing description of the preferred embodiments of the invention is not intended to limit the invention to the precise form disclosed, and any such modifications, equivalents, and alternatives falling within the spirit and scope of the invention are intended to be included within the scope of the invention.

Claims

1. A lead mesh-based water splitting hydrogen production device comprising an anode, a cathode and a membrane, characterized in that it uses a lead mesh covered with a lead oxide sheet as the anode, a platinized lead mesh or titanium mesh or alloy mesh as the cathode, and a Proton Exchange Membrane (PEM) as the membrane.

2. The lead net-based water splitting hydrogen production device of claim 1, wherein: the anode, the diaphragm and the cathode are sequentially overlapped to form the main body of the water decomposition hydrogen production device.

3. The lead net-based water splitting hydrogen production device of claim 2, wherein: the extension sections of the anode and the cathode are respectively provided with a direct current power supply interface; in the hydrogen production process, a direct current power supply is connected with a lead-net-based water decomposition hydrogen production device through a direct current power supply interface, electrons flowing out of a negative electrode of the power supply flow into electrolyte through a cathode, meanwhile, reduction reaction occurs on the surface of the cathode, and hydrogen ions of the electrolyte near the cathode obtain electrons to generate hydrogen.

4. The lead net-based water splitting hydrogen production plant of claim 3, wherein: the Proton Exchange Membrane (PEM) is a perfluorosulfonic acid type proton exchange membrane, a Nafion recast membrane, a non-fluoropolymer proton exchange membrane or a novel composite proton exchange membrane.

5. A method for preparing a lead-net-based water-splitting hydrogen production device, which is characterized by comprising the following steps:

step 1, preparing an anode lead net; plating a layer of nano platinum on the lead net by using a sputtering coating machine and directly using the nano platinum as an anode; or placing the lead net in a polytetrafluoroethylene cup filled with concentrated ammonia water, reacting at the high temperature and the high pressure of 180 ℃ for 6 to 72 hours, and growing a layer of lead oxide sheet on the lead net to serve as an anode;

step 2, preparing a cathode, and plating a layer of nano platinum on the lead foil by using a sputtering coating machine to directly serve as the cathode;

6. The method of manufacturing according to claim 5, wherein:

the step 2 directly produces a platinum carbon Proton Exchange Membrane (PEM) membrane for the anode of a PEM fuel cell as the cathode and membrane of a hydrogen plant.

7. A method of using the lead mesh-based water splitting hydrogen plant of any of claims 1-4, comprising the steps of:

step 1, connecting a direct current power supply interface with a direct current power supply, connecting an anode with the positive electrode of the direct current power supply, and connecting a cathode with the negative electrode of the direct current power supply;

step 2, placing the lead-net-based water-splitting hydrogen production device in an acidic aqueous solution, arranging a direct-current power interface on the liquid level, and avoiding the contact of a circuit with the aqueous solution;

step 3, turning on a power switch, starting from 2V, slowly increasing the voltage, and adjusting to a proper voltage according to the hydrogen demand, wherein if the hydrogen demand is large, the voltage is high, and if the hydrogen demand is small, the voltage is low;