PFSA Proton Exchange Membrane - Reinforced - Gas Recombination Catalyst Layer, D80R-Pt, D50R-Pt

Perfluorosulfonic acid (PFSA) polymer chemistry based proton exchange membranes or PEM (also known as cation exchange membranes, CEM) have been the golden standard in the industry for more than 30 years for numerous electrochemical and non-electrochemical applications.

Product Information

This product page discloses the product details of two different PFSA Proton Exchange Membrane - Reinforced - Gas Recombination Catalyst Layer, namely D80R-Pt and D50R-Pt. Membrane thickness for D80R-Pt is approximately 80 micrometers (~3.1 mil). D50R-Pt membrane has a thickness of ~50 microns (~2 mil). Both of these membrane products belong to the reinforced category, i.e., there is a mechanical reinforcement web in them. The reinforcement is based on the ePTFE (also known as expanded PTFE) and provides excellent mechanical robustness.  Gas recombination catalyst layer (which is an integral part of the membrane) is composed of Pt based nanoparticles and will recombine the crossing over gas species (H2 and O2 molecules) and generate water molecules as a result of the recombination reaction. Previous research demonstrates that making the gas recombination an integral part of the membrane is the most promising way to modify these proton exchange membranes in a way to reduce the gas crossover issues. Presence of ePTFE mechanical reinforcement, Pt-based gas recombination catalyst layer, and manufacturing the final membrane product in a thickness of ~80 microns truly brings the best of the all components and makes this membrane product an ideal proton exchange membrane for pressurized and unpressurized PEM electrolyzer stacks.  D50R-Pt, on the other hand is an ideal proton exchange membrane for atmospheric and pressurized proton exchange membrane fuel cells (PEMFC) stacks. While it is not common to use 80 micrometers thick membranes for PEMFC stacks, certain applications such as regenerative fuel cells operating at high pressures can benefit from 80 micrometers thick membrane.  PEM electrolysis applications has been mainly using PFSA membranes thicker than 50 micrometers for safety and longevity reasons, though atmospheric PEM electrolyzers can greatly benefit from D50R-Pt membrane when superior electrochemical performance is required.

Both D80R-Pt and D50R-Pt membranes are manufactured via solution casting process. Chemically stabilized PFSA resin is used in the production of these membranes to achieve longevity for the demanding applications. The polymer structure of these membranes are based on the long-side-chain PFSA for its chemical composition. Proton exchange membranes based on the long-side-chain PFSA will usually exhibit superb proton or ionic conductivity as a result of their affinity to interact with water molecules and keep these within the membrane itself.  This affinity towards water molecules also induces swelling in the membrane. The presence of ePTFE reinforcement reduces the degree of swelling greatly (for the length and width aspects) for these membranes compared to the unreinforced membrane products.

D80R-Pt membrane is usually considered to be intermediate thickness compared to other reinforced membranes available in the market. When mechanical robustness, low gas crossover, and longevity are the critical determinants in a product development, use of this membrane product is recommended. D50R-Pt, on the other hand, can be considered as a thin to intermediate thickness for its application range compared to other reinforced membranes available in the market.  Demanding PEMFC applications such as pressurized H2/Air and H2/O2 reactants consuming fuel cell stacks will greatly benefit from the use of D50R-Pt membrane. Examples of applications that can benefit from these membranes are given below. 

Main specifications:

Electrochemical tests of D80R-Pt

Electrochemical tests of D50R-Pt

Other features:

• Reinforcement: Yes, ePTFE Reinforced
• Gas recombination catalyst layer: Yes, Pt nanoclusters are used as the gas recombination catalyst
• Stabilization: Chemically stabilized, also known as fully fluorinated end-groups
• EW (Equivalent weight): In the range of 950-1000 EW
• Polymer Structure: Long-side-chain PFSA
• Production method: Solution casting process
  
• Standard availability: 30×30cm 

Please see the table below for the list of our proton exchange membranes for electrolysis and other applications.

Important note: Proton exchange membranes containing gas recombination catalyst layers will naturally have lower gas crossover specifications of the same/similar thickness counterparts that do not have the gas recombination catalyst layer (reinforced or unreinforced).

Storage:

• The product must be kept in a sealed package before use; once the box is opened, it must be stored in an environment with temperature of 23±5°C and relative humidity of 50±5%, and use it as soon as possible.
• Store the product away from direct sunlight, heat and dust.

Please let us know if you want larger sizes or other thickness at info@elelctrohy.com.

More Information on PFSA Membranes

There have been three categories of the PFSA-based proton exchange membranes for their polymer structures, namely long-side-chain (LSC) PFSA, medium-side-chain (MSC) PFSA, and short-side-chain (SSC) PFSA. Chemours' Nafion™ is a good example for the PEMs that are based on the long-side-chain PFSA. 3M's Dyneon™ PFSA is a good example for the PEMs that are based on  the medium-side-chain PFSA.  Syensqo's Aquivion® is a good example for the PEMs that are based on the short-side-chain PFSA. 

Polymer Structure of PFSA Membranes

The following two images provide the polymer structure of different PFSA membranes and different sections of the polymer chain labeled.

The above image is courtesy of Delfino et. al. for their publication that is entitled "Short Side-Chain Perfluorosulfonic Acid Aquivion: From Production to Application".

The above image is courtesy of Wang et. al. for their publication that is entitled "Cathode Design for Proton Exchange Membrane Fuel Cells in Automotive Applications".

Nano-structure of PFSA Membranes

Perfluorosulfonic acid (PFSA) membranes have a very unique property as a result of having hydrophilic and hydrophobic segments in their polymer backbone and this is known as phase separation. Multiple sulfonic acid based side chains will cluster together to form a hydrophilic domain.  TFE domains will also form a cluster amongst themselves and form a hydrophobic domain.  The following is a phenomenological sketch of the nano-structure for Nafion-based PFSA membrane that shows the phase separation into three regions: perfluorinated hydrocarbon backbone, side chains with fixed sulfonic acid end groups, and water region (the image is courtesy of Haubold et al. for their publication entitled as "Nano Structure of Nafion: A SAXS Study").

To further clarify the cluster-network model for the morphology of the hydrated PFSA membranes, the following pictorial description is an excellent depiction how such materials behave at the nano-scale. The image below is courtesy of Mauritz and Moore from their article entitled " State of Understanding Nafion" which is an excellent publication to review and understand most aspects of PFSA membranes.

Summary of Potential Applications for These Products

The following are simply some of the examples that used PFSA membrane based products. Researchers and end-users exploring these applications, and other electrohemical and non-electrochemical use cases can benefit from this product.

Clean Energy and Power Generation

1. Atmospheric and Pressurized H2-Air PEM Fuel Cells (such as PEMFC stacks for heavy duty trucks, automotive applications, residential applications, open- and closed-cathode fuel cell stacks for UAVs and drones, etc.)
   
2. Vanadium Redox Flow Batteries VRFBs)
3. Atmospheric or Pressurized Hydrogen-Oxygen PEM Fuel Cells (H2/O2 PEMFCs)
4. Microbial Fuel Cells (MFCs)
5. Formic Acid Fuel Cells (FAFCs)
6. Direct Methanol Fuel Cells (DMFCs)

Hydrogen Production and Gas Systems

1. Atmospheric and Pressurized Proton Exchange Membrane Water Electrolysis (PEMWE)
2. Thermochemical Water Splitting
3. Gas Drying and Humidification
4. Analytical Instrumentation Gas Prep
5. Microbial-assisted PEM electrolysis
6. Microbial-assisted salt removal or desalination (also known as self-powered microbial desalination)

Industrial and Chemical Synthesis

1. Chlor-alkali Cells
2. Heterogeneous Superacid Catalysis
3. Heavy Metal Ion Recovery
4. Electroplating and Metal Surface Finishing
5. Electrochemical Synthesis of Fine Chemicals

Sensors and Advanced Materials

1. Solid-state Electrochemical Sensors
2. Biosensors and Medical Diagnostic Tools
3. Ion-conducting Artifical Muscles (IPMCs)