Preparation Process of CCM Method

CCM (Catalyst Coated Membrane) method, namely catalyst coating membrane method, is a method of directly coating the catalyst on both sides of the proton exchange membrane to form a catalytic layer. Its main preparation process is as follows:

1. Material preparation

  • Proton exchange membrane:
    Select a proton exchange membrane with high proton conductivity, good chemical stability and mechanical strength, such as perfluorosulfonic acid membrane.
    Pretreatment of the proton exchange membrane usually includes steps such as cleaning and drying to remove impurities and moisture on the membrane surface.
  • Catalyst:
    The catalyst is usually a platinum-based catalyst, such as platinum carbon (Pt/C) catalyst.
    Parameters such as particle size, specific surface area, and platinum loading of the catalyst will affect its catalytic performance.
    Different types of catalysts, such as alloy catalysts, core-shell catalysts, etc., can be selected as needed to improve the activity and stability of the catalyst.
  • Solvent:
    Select a suitable solvent for preparing catalyst slurry. Commonly used solvents include alcohols (such as isopropanol, ethanol), water, etc.
    The choice of solvent should consider its solubility, volatility and environmental impact on the catalyst and proton exchange membrane.
  • Other additives:
    In order to improve the performance of the catalyst slurry, some additives such as binders, dispersants, etc. can be added.
    Binders can improve the bonding force between the catalyst and the proton exchange membrane, and dispersants can improve the dispersibility of the catalyst in the slurry.

Preparation Process of CCM Method - Catalyst Coated Membrane

2. Catalyst slurry preparation

  • Formulation design:
    The catalyst slurry formula is determined according to the type, loading and characteristics of the proton exchange membrane.
    Generally speaking, the content of catalyst in the catalyst slurry is 10%~50% (mass fraction), the content of binder is 1%~10% (mass fraction), and the content of dispersant is 0.1%~1% (mass fraction).
  • Mixing and stirring:
    Add the catalyst, binder, dispersant and solvent to the stirring container in a certain proportion.
    Use a stirrer or ultrasonic equipment to stir or ultrasonically treat the mixture so that the catalyst is evenly dispersed in the solvent.
    The stirring time and ultrasonic treatment time depend on the type of catalyst and the viscosity of the slurry, generally from a few hours to more than ten hours.
  • Adjusting performance:
    Adjust the performance of the catalyst slurry, such as viscosity, solid content, pH value, etc.
    The performance of the slurry can be adjusted by adding solvents or adjusting the content of additives to meet the requirements of the coating process.

3. Coating process

  • Direct coating method:
    Spread the proton exchange membrane flat on the coating platform, and use a scraper or spray gun to evenly coat the catalyst slurry on both sides of the membrane.
    Controlling the thickness and uniformity of the coating can be achieved by adjusting parameters such as the height of the scraper, the pressure and flow rate of the spray gun.
    The coated membrane is dried at a certain temperature to remove the solvent and form a catalytic layer.
  • Transfer method:
    First, the catalyst slurry is coated on a transfer substrate, such as a polytetrafluoroethylene (PTFE) membrane or a polyester (PET) membrane.
    Then the proton exchange membrane is pressed on the transfer substrate coated with the catalyst slurry, and the catalyst is transferred to both sides of the membrane by hot pressing or rolling.
    Finally, the transfer substrate is removed to obtain a proton exchange membrane coated with a catalytic layer.

4. Post-treatment process

  • Hot pressing treatment:
    The proton exchange membrane coated with the catalytic layer is hot pressed at a certain temperature and pressure to improve the bonding force between the catalyst and the proton exchange membrane.
    The hot pressing temperature is generally 100℃~200℃, the pressure is 1~10 MPa, and the hot pressing time is a few minutes to tens of minutes.
  • Drying treatment:
    The hot pressed proton exchange membrane is dried to remove residual solvent and moisture.
    The drying temperature is generally 80℃~120℃, and the drying time is a few hours to more than ten hours.
  • Detection and evaluation:
    The prepared CCM is tested and evaluated, including the thickness, uniformity, platinum loading, proton conductivity, gas permeability and other performance indicators of the catalytic layer.
    According to the test results, the preparation process is adjusted and optimized to improve the performance and quality of CCM.

The above are the main preparation processes of the CCM method. Different research institutions and enterprises may make some adjustments and improvements according to their actual conditions.

Electrolyzers & Fuel Cell Coating

Hydrogen production by electrolysis of water is the most advantageous method for producing hydrogen. Utrasonic coating systems are ideal for spraying carbon-based catalyst inks onto electrolyte membranes used for hydrogen generation. This technology can improve the stability and conversion efficiency of the diaphragm in the electrolytic water hydrogen production device. Cheersonic has extensive expertise coating proton exchange membrane electrolyzers, creating uniform, effective coatings possible for electrolysis applications.

Cheersonic ultrasonic coating systems are used in a number of electrolysis coating applications. The high uniformity of catalyst layers and even dispersion of suspended particles results in very high efficiency electrolyzer coatings, either single or double sided.

About Cheersonic

Cheersonic is the leading developer and manufacturer of ultrasonic coating systems for applying precise, thin film coatings to protect, strengthen or smooth surfaces on parts and components for the microelectronics/electronics, alternative energy, medical and industrial markets, including specialized glass applications in construction and automotive.

Our coating solutions are environmentally-friendly, efficient and highly reliable, and enable dramatic reductions in overspray, savings in raw material, water and energy usage and provide improved process repeatability, transfer efficiency, high uniformity and reduced emissions.

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