Carbon dioxide electro-catalytic reactor

Abstract

The utility model relates to a carbon dioxide electro-catalytic reactor, which comprises an anode chamber, a cathode chamber and an anode chamber, a mixed gas containing carbon dioxide and water is introduced into the cathode chamber; the anode chamber and the cathode chamber are separated by the functional layer, the functional layer comprises a cathode catalyst layer located on one side of the cathode chamber and an anode catalyst layer located on one side of the anode chamber, and the functional layer is further provided with an anion exchange layer located between the anode catalyst layer and the cathode catalyst layer. According to the carbon dioxide electro-catalytic reactor, the mass transfer resistance of the functional layer is reduced by improving the functional layer, so that the reaction rate and the reaction efficiency of the reactor can be improved, and the conversion rate of a reaction system is improved. Specifically, a functional layer of a multi-layer membrane in the prior art is simplified into a single ion exchange membrane, and a two-cavity structure is formed, so that the structure of the functional layer is simplified, and the purpose of reducing the mass transfer resistance of the functional layer is achieved.

Description

Technical Field

[0001] This utility model relates to the field of carbon dioxide electrocatalytic reduction technology, specifically to a carbon dioxide electrocatalytic reactor. Background Technology

[0002] With climate change and the greenhouse effect receiving increasing attention, carbon dioxide sequestration technology is a highly promising technology for reducing carbon emissions, controlling the greenhouse effect, and addressing climate change. Electrocatalytic conversion of carbon dioxide is one of the known effective technological routes for achieving carbon dioxide capture and sequestration. Carbon is sequestrated by electrolytically reducing carbon dioxide into other organic products.

[0003] The applicant has already filed a Chinese invention patent (application number 2023104783353) entitled "Carbon Dioxide Electrocatalytic Reactor," proposing a carbon dioxide electrocatalytic reactor with a two-chamber structure separated by multilayer functional membranes. Although it initially achieved carbon dioxide conversion and fixation, the effect was not ideal. The presence of the multilayer functional membrane structure hinders electron transport, slowing down the overall reaction rate. Furthermore, with prolonged use, the performance of the functional membranes degrades, further reducing the carbon dioxide fixation efficiency of the reaction equipment. Utility Model Content

[0004] In view of the problem that the multilayer membrane structure in existing carbon dioxide electrocatalytic reactors leads to the obstruction of ion transport, making it difficult to effectively maintain and improve the conversion rate and efficiency, this utility model provides a carbon dioxide electrocatalytic reactor.

[0005] This application provides a carbon dioxide electrocatalytic reactor, comprising:

[0006] An anode chamber, wherein an aqueous liquid is introduced;

[0007] A cathode chamber, wherein a mixed gas containing carbon dioxide and water is introduced;

[0008] The functional layer separates the anode chamber and the cathode chamber. The functional layer includes a cathode catalyst layer located on one side of the cathode chamber and an anode catalyst layer located on one side of the anode chamber, and also has an anion exchange layer between the anode catalyst layer and the cathode catalyst layer.

[0009] Preferably, the functional layer further includes an ion exchange resin; the ion exchange resin is formed between the anode catalyst layer and the anion exchange layer, or the ion exchange resin is formed between the cathode catalyst layer and the anion exchange layer.

[0010] Preferably, the functional layer further includes an ion exchange resin; the ion exchange resin is formed between the anode catalyst layer and the anion exchange layer, and the ion exchange resin is formed between the cathode catalyst layer and the anion exchange layer.

[0011] Preferably, the anode catalyst layer is a titanium felt substrate with a surface-supported anode catalyst.

[0012] Preferably, the cathode catalyst layer is a gas diffusion type carbon paper with a cathode catalyst supported on its surface.

[0013] Preferably, the aqueous liquid introduced into the anode chamber is pure water.

[0014] Preferably, the aqueous liquid introduced into the anode chamber is an aqueous solution of formate.

[0015] The carbon dioxide electrocatalytic reactor of this application reduces the mass transfer resistance of the functional layer by improving it, thereby increasing the reaction rate and efficiency of the reactor and improving the conversion rate of the reaction system. Specifically, the functional layer of the multilayer membrane in the prior art is simplified into a single ion exchange membrane forming a two-chamber structure, thereby simplifying the structure of the functional layer and reducing its mass transfer resistance. Because the functional layer reduces the resistance to ion transport, it also reduces ion accumulation at the anode and cathode catalyst layers, thus extending the activity time of the anode and cathode catalyst layers and increasing the interval required to activate the catalyst. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the carbon dioxide electrocatalytic reactor of this utility model.

[0017] In the picture:

[0018] 1: Anode chamber; 2: Cathode chamber; 3: Functional layer; 31: Anode catalyst layer; 32: Ion exchange resin; 33: Anion exchange layer; 35: Cathode catalyst layer. Detailed Implementation

[0019] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. In this specification, the dimensions of the drawings do not represent the actual dimensions. They are only used to illustrate the relative positional and connection relationships between the components. Components with the same name or the same reference numeral represent similar or identical structures and are limited to illustrative purposes.

[0020] Figure 1This is a schematic diagram of the carbon dioxide electrocatalytic reactor of this application. The reactor first includes an anode chamber 1 and a cathode chamber 2 separated by a functional layer 3. In application, an aqueous liquid, which can be pure water or an aqueous solution of certain salts, is introduced into the anode chamber 1. Since formic acid is produced at the anode, the aqueous liquid introduced into the anode chamber 1 can be pure water to ensure the simplicity of the product solution composition and ease of handling. The aqueous liquid can also be a formate, in which case the anions in the output liquid of the anode chamber 1 are still only formate ions, thus facilitating subsequent purification. The aqueous solution of a specific salt injected into the anode chamber 1 is mainly for the purpose of improving the conductivity of the liquid in the anode chamber. Anionic salts other than formate can be introduced into the anode chamber 1, but this is generally not a preferred option because it introduces impurity anions, which is usually detrimental to subsequent purification. In the cathode chamber 2 of the reactor, a mixed gas containing carbon dioxide and water, such as humidified carbon dioxide gas, is introduced.

[0021] Functional layer 3 is a multilayer membrane structure, comprising at least an anode catalyst layer 31 on one side of anode chamber 1, a cathode catalyst layer 35 on one side of cathode chamber 2, and an anion exchange layer 33 between the anode catalyst layer 31 and the cathode catalyst layer 35. Generally, on the cathode catalyst layer 35, a mixture containing carbon dioxide and water undergoes a reduction reaction to produce formate ions. On the anode catalyst layer 31, water molecules are oxidized to produce hydrogen ions. Carbonate ions enter the anode chamber 1 via the anion exchange layer 33, forming a formic acid solution system in the anode chamber 1. In this technical solution, there is no multilayer ion-exchange membrane structure between the two chambers; only an anion exchange membrane exists, eliminating the need for a cation exchange membrane. Since ion exchange membranes offer significant resistance to ion transport, eliminating the cation exchange membrane significantly improves the ion flow rate and efficiency between anode chamber 1 and cathode chamber 2. In this case, the reactor's reaction rate and efficiency are enhanced.

[0022] The anodic catalyst layer 31 in functional layer 3 is generally a catalyst-supported titanium anode felt. It is formed on a titanium felt substrate using oxides and hybrids containing metallic iridium, iron, cobalt, nickel, copper, and molybdenum, through high-temperature sintering. The cathode catalyst layer 35 in functional layer 3 is generally a catalyst-supported carbon cathode paper. It is obtained by spraying a uniformly mixed catalyst solution onto gas-diffusion carbon paper. The catalyst is selected from metal nanoarrays, alloys, metal oxides, sulfides, etc., containing metallic bismuth, tin, antimony, and indium. The cathode catalyst, solvent, and Nafion solution can be ultrasonically mixed to obtain a uniform spray solution.

[0023] In fact, due to the bonding issues between the anode catalyst layer 31, the cathode catalyst layer 35, and the anion exchange layer 33, the ions obtained by electrolysis on the anode catalyst layer 31 and the cathode catalyst layer 35 do not directly contact the anion exchange layer 33, which also leads to an increase in mass transfer resistance. Specifically, in a pure water anode system, the ions ionized on the anode catalyst layer 31 need to be transported through a pure water medium to reach the anion exchange layer 33, resulting in a large ion transport resistance. The same problem exists in the cathode chamber 2. In order to reduce the mass transfer resistance of the system and improve the reaction efficiency of the system, it is preferable to provide anion exchange resin 32 on at least one side of the anion exchange layer 33.

[0024] An ion exchange resin 32 can be disposed between the anode catalyst layer 31 and the anion exchange layer 33, with both sides of the ion exchange resin 32 contacting the anode catalyst layer 31 and the anion exchange layer 33 respectively. This sufficient contact at the interface allows ions generated on the anode catalyst layer 31 to travel through the ion exchange resin 32 to the anion exchange layer 33, thus reducing ion transport resistance. Similarly, the ion exchange resin 32 can be disposed not only between the anode catalyst layer 31 and the anion exchange layer 33, but also between the anion exchange layer 33 and the cathode catalyst layer 35 to reduce ion transport resistance between the cathode catalyst layer 35 and the anion exchange layer 33 within the cathode chamber 2. Because the ion exchange resin 32 reduces the ion transport resistance of the system, it can significantly improve the reaction rate and efficiency. Furthermore, the timely transport of anode and cathode products reduces accumulation at the electrodes and catalyst layers, which also helps to extend the activity time of the corresponding catalyst layers and prolong the interval required for reactivation of the functional membrane.

[0025] Current carbon dioxide electrocatalytic electrolyzers generally have a short lifespan and can operate stably for a short period. This is likely due to the complex internal structure of the electrolyzer and the limitations of the materials used. Typical carbon dioxide electrocatalytic conversion processes require the use of cation and anion exchange membranes and specific electrolyte solutions as ion exchange channels in the reactor; however, these media exhibit significant mass transfer resistance, resulting in low energy conversion efficiency.

[0026] This process aims to overcome the technical problems of current carbon dioxide catalytic electrolyzers by employing a simpler electrolyzer structure. It utilizes only anode and cathode catalysts and anion exchange membranes, and the entire reaction involves only carbon dioxide and water. Furthermore, the anion exchange membrane and anode and cathode catalysts are in direct contact, reducing mass transfer resistance. Formic acid products are directly produced from the anode, facilitating product collection. This relatively simple electrolyzer structure also improves the overall stability of the electrolyzer's performance, facilitating long-term operation, assembly, and material replacement.

[0027] The attached table shows the test data of the carbon dioxide electrolyzer made using the above-described structure and functional materials under standard operating conditions. It can be determined that the two-chamber carbon dioxide electrocatalytic reactor of this application can operate stably for a long time with the support of the electrolyzer activation system, with a continuous working time of over 1294 hours, and its Faraday efficiency can also remain stable at a relatively high value, resulting in higher reaction conversion efficiency.

[0028] Appendix:

[0029]

[0030] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the scope of the present utility model. Any modifications and improvements made to the technical solution of the present utility model by those skilled in the art without departing from the spirit of the present utility model should fall within the protection scope defined by the claims of the present utility model.

Claims

1. A carbon dioxide electrocatalytic reactor, characterized by, include: Anode chamber (1), wherein an aqueous liquid is introduced; A cathode chamber (2) is introduced into which a mixed gas containing carbon dioxide and water is introduced; The functional layer (3) separates the anode chamber (1) and the cathode chamber (2). The functional layer (3) includes a cathode catalyst layer (35) located on one side of the cathode chamber (2) and an anode catalyst layer (31) located on one side of the anode chamber (1). It also has an anion exchange layer (33) between the anode catalyst layer (31) and the cathode catalyst layer (35).

2. The carbon dioxide electrocatalytic reactor as described in claim 1, characterized in that, The functional layer (3) further includes an ion exchange resin (32); the ion exchange resin (32) is formed between the anode catalyst layer (31) and the anion exchange layer (33), or the ion exchange resin (32) is formed between the cathode catalyst layer (35) and the anion exchange layer (33).

3. The carbon dioxide electrocatalytic reactor as described in claim 1, characterized in that, The functional layer (3) further includes an ion exchange resin (32); the ion exchange resin (32) is formed between the anode catalyst layer (31) and the anion exchange layer (33), and the ion exchange resin (32) is formed between the cathode catalyst layer (35) and the anion exchange layer (33).

4. The carbon dioxide electrocatalytic reactor according to any one of claims 1-3, characterized in that, The anode catalyst layer (31) is a titanium felt substrate with a surface-supported anode catalyst.

5. The carbon dioxide electrocatalytic reactor according to any one of claims 1-3, characterized in that, The cathode catalyst layer (35) is a gas diffusion type carbon paper with a cathode catalyst supported on its surface.

6. The carbon dioxide electrocatalytic reactor according to any one of claims 1-3, characterized in that, The aqueous liquid introduced into the anode chamber (1) is pure water.

7. The carbon dioxide electrocatalytic reactor according to any one of claims 1-3, characterized in that, The aqueous liquid introduced into the anode chamber (1) is an aqueous solution of formate.

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