Gas diffusion layer for electrochemical reduction of carbon dioxide and preparation method of gas diffusion layer

Abstract

The invention relates to a gas diffusion layer for electrochemical reduction of carbon dioxide and a preparation method of the gas diffusion layer. The gas diffusion layer is composed of a substrate layer and a microporous layer. The preparation method comprises the following steps: soaking the substrate layer with a water repellent agent; carrying out drying treatment on the soaked substrate layer; a hydrophobic agent, a conductive material and a solvent are blended to prepare a mixed emulsion, and then one side of the dried substrate layer is coated with the mixed emulsion to form a microporous layer; and finally performing high-temperature treatment to prepare the gas diffusion layer. The gas diffusion layer is suitable for the technical field of carbon dioxide electrochemical reduction, the porosity is 70% or above, the pore volume of the hydrophobic pores accounts for 90% or above of the total pore volume, the diffusion layer comprises the hydrophobic micropores with the pore diameter smaller than 5 micrometers, and mass transfer of carbon dioxide gas in a gas diffusion electrode can be promoted. The preparation method of the gas diffusion layer provided by the invention is simple in preparation process and can be amplified on a large scale, and a carbon dioxide reduction electrolytic tank assembled by using the gas diffusion layer as a cathode diffusion layer shows very high running current density and has very high application value.

Description

technical field

[0001] The present invention relates to the electrolysis technology of carbon dioxide electrochemical reduction, in particular to a gas diffusion layer for the electrochemical reduction of carbon dioxide and its preparation method, in particular to a carbon dioxide electrolysis layer composed of a base layer, a conductive material and a hydrophobic agent. Chemically reduced gas diffusion layer and method for its preparation. Background technique

[0002] Carbon dioxide electrochemical reduction technology can use renewable electricity to convert carbon dioxide into high value-added chemicals and fuels, such as carbon monoxide, formic acid, ethylene, etc. The storage of energy provides a potential method and has become one of the research hotspots in the energy field.

[0003] In addition to electrochemical catalysts, the mass transfer of gaseous carbon dioxide is also a key issue in the electrochemical reduction of carbon dioxide. Judging from the literatur...

Examples

preparation example Construction

[0037] The preparation method of the aforementioned gas diffusion layer comprises the following steps:

[0038] 1) Immerse the base layer in a certain concentration of hydrophobic agent emulsion for 1-60s, then take it out and dry it at 50-80°C to constant weight;

[0039] 2) Repeat the above process until the base layer and hydrophobic agent reach a certain mass ratio, the mass ratio range is 1:0.05~1:4;

[0040] 3) Mix the conductive material, the hydrophobic agent emulsion and the dispersant, stir fully to make the conductive material and the hydrophobic agent fully contact, and obtain the microporous layer slurry; the mass ratio of the conductive material to the hydrophobic agent is 1:0.05~1:2 The dispersant is a mixture of one or more of dehydrated alcohol, isopropanol, ultrapure water, etc. mixed in any proportion;

[0041]4) Deposit the conductive material / hydrophobic agent mixed slurry obtained in step 3) onto one side of the base layer treated with the hydrophobic ag...

Embodiment 1

[0046] This embodiment relates to a gas diffusion layer for electrolytic electrochemical reduction of carbon dioxide and its preparation method, the steps are as follows:

[0047] 1) Soak the WOS1009 carbon cloth produced by Carbon Energy CeTech Company in 5wt% polytetrafluoroethylene emulsion for 30 seconds, take it out and vacuum dry it to a constant weight in a drying oven at 60°C. Repeat the above steps until the weight difference between the impregnated and dried carbon cloth accounts for 30wt% of the total weight of the impregnated and dried carbon cloth.

[0048] 2) Mix 5g of Vulcan XC-72 conductive carbon black, 25g of 5wt% polytetrafluoroethylene emulsion (containing 1.25g of polytetrafluoroethylene) and 10g of absolute ethanol, stir well to make it evenly mixed.

[0049] 3) Coating the emulsion in 2) by screen printing on one surface of the 6×11 cm carbon cloth obtained in 1) after the hydrophobic treatment, to obtain a diffusion electrode layer precursor.

[0050] ...

Embodiment 2

[0055] A gas diffusion layer for electrolytic electrochemical reduction of carbon dioxide and a preparation method thereof, the steps are as follows:

[0056] 1) Soak Toray TGP-H-060 carbon paper produced by Toray Corporation in Japan in 5wt% polytetrafluoroethylene emulsion for 30 seconds, take it out and vacuum-dry it in a drying oven at 60°C to a constant weight. Repeat the above steps until the weight difference between the impregnated and dried carbon cloth accounts for 10wt% of the total weight of the impregnated and dried carbon cloth.

[0057] 2) 1g Vulcan XC-72R conductive carbon black, 0.42g 60wt% polytetrafluoroethylene emulsion (containing 0.25g polytetrafluoroethylene), 0.1g ultrapure water and 0.2g isopropanol were ultrasonically treated for 30 minutes.

[0058] 3) Spray-coat the uniform emulsion obtained in 2) on one side of Toray TGP-H-060 carbon paper, and the loading amount of conductive carbon black in the microporous layer is 1 mg cm -2 , to obtain the pre...

technical field

[0001] The present invention relates to the electrolysis technology of carbon dioxide electrochemical reduction, in particular to a gas diffusion layer for the electrochemical reduction of carbon dioxide and its preparation method, in particular to a carbon dioxide electrolysis layer composed of a base layer, a conductive material and a hydrophobic agent. Chemically reduced gas diffusion layer and method for its preparation. Background technique

[0002] Carbon dioxide electrochemical reduction technology can use renewable electricity to convert carbon dioxide into high value-added chemicals and fuels, such as carbon monoxide, formic acid, ethylene, etc. The storage of energy provides a potential method and has become one of the research hotspots in the energy field.

[0003] In addition to electrochemical catalysts, the mass transfer of gaseous carbon dioxide is also a key issue in the electrochemical reduction of carbon dioxide. Judging from the literatur...

Examples

preparation example Construction

[0037] The preparation method of the aforementioned gas diffusion layer comprises the following steps:

[0038] 1) Immerse the base layer in a certain concentration of hydrophobic agent emulsion for 1-60s, then take it out and dry it at 50-80°C to constant weight;

[0039] 2) Repeat the above process until the base layer and hydrophobic agent reach a certain mass ratio, the mass ratio range is 1:0.05~1:4;

[0040] 3) Mix the conductive material, the hydrophobic agent emulsion and the dispersant, stir fully to make the conductive material and the hydrophobic agent fully contact, and obtain the microporous layer slurry; the mass ratio of the conductive material to the hydrophobic agent is 1:0.05~1:2 The dispersant is a mixture of one or more of dehydrated alcohol, isopropanol, ultrapure water, etc. mixed in any proportion;

[0041]4) Deposit the conductive material / hydrophobic agent mixed slurry obtained in step 3) onto one side of the base layer treated with the hydrophobic ag...

Embodiment 1

[0046] This embodiment relates to a gas diffusion layer for electrolytic electrochemical reduction of carbon dioxide and its preparation method, the steps are as follows:

[0047] 1) Soak the WOS1009 carbon cloth produced by Carbon Energy CeTech Company in 5wt% polytetrafluoroethylene emulsion for 30 seconds, take it out and vacuum dry it to a constant weight in a drying oven at 60°C. Repeat the above steps until the weight difference between the impregnated and dried carbon cloth accounts for 30wt% of the total weight of the impregnated and dried carbon cloth.

[0048] 2) Mix 5g of Vulcan XC-72 conductive carbon black, 25g of 5wt% polytetrafluoroethylene emulsion (containing 1.25g of polytetrafluoroethylene) and 10g of absolute ethanol, stir well to make it evenly mixed.

[0049] 3) Coating the emulsion in 2) by screen printing on one surface of the 6×11 cm carbon cloth obtained in 1) after the hydrophobic treatment, to obtain a diffusion electrode layer precursor.

[0050] ...

Embodiment 2

[0055] A gas diffusion layer for electrolytic electrochemical reduction of carbon dioxide and a preparation method thereof, the steps are as follows:

[0056] 1) Soak Toray TGP-H-060 carbon paper produced by Toray Corporation in Japan in 5wt% polytetrafluoroethylene emulsion for 30 seconds, take it out and vacuum-dry it in a drying oven at 60°C to a constant weight. Repeat the above steps until the weight difference between the impregnated and dried carbon cloth accounts for 10wt% of the total weight of the impregnated and dried carbon cloth.

[0057] 2) 1g Vulcan XC-72R conductive carbon black, 0.42g 60wt% polytetrafluoroethylene emulsion (containing 0.25g polytetrafluoroethylene), 0.1g ultrapure water and 0.2g isopropanol were ultrasonically treated for 30 minutes.

[0058] 3) Spray-coat the uniform emulsion obtained in 2) on one side of Toray TGP-H-060 carbon paper, and the loading amount of conductive carbon black in the microporous layer is 1 mg cm -2 , to obtain the pre...

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