Ultra-thin titanium (Grade 2 based) porous transfer layer is one of the thinnest products on the market that can be used as the anode diffusion media in standard PEM electrolyzers. Metallic or titanium-based electrodes are primarily used in standard PEM electrolyzers as the flow field or diffusion material, particularly on the oxygen (anode) side and it is essential that such products have better mass transport and a smaller footprint. This porous transfer layer achieves that.
Since electrolyzer hardwares cannot use carbon-based gas diffusion layers (GDLs) at the anode because the carbon will immediately oxidize to CO2 (if the medium is acidic) or carbonate ions (if the medium is basic) during the reaction. Titanium porous transfer layer becomes an ideal candidate as the diffusion medium. A titanium porous transfer layer also provides electrical contact between the anode catalyst layer and bipolar plate or current collector component at the anode.
This product has a thickness of ~0.010" (250 microns). While the most industrial applications operate their electrolyzers in anode-fed mode, this product is also an ideal diffusion medium for researchers conducting cathode-fed electrolyzer research.
For unitized fuel cells or electrolyzers or regenerative electrochemical devices systems, titanium fiber felt can be used at anode or cathode as the diffusion medium. Electrochemical oxygen concentrators, electrochemical inerters, certain classes of batteries (such as redox flow batteries) can also benefit from this product as the diffusion medium regardless of the nature of the reactants.
For applications that contain salts, acids, or bases, care needs to be given so those chemical compounds do not interact with the titanium porous transfer layer in the negative way (such as surface oxidation, chemical dissolution, etc.).
When Should I use a Platinized Titanium Porous Transfer Layer?
Untreated titanium porous transfer will not be consumed like a carbon Gas Diffusion Layer (GDL) will. However, the presence of oxygen does have an impact if the electrolyzer is being operated at high pressures (1 bar to 3 bars). The untreated titanium surface will quickly form an electrically insulated oxide layer (TiO2) on the surface of the of the small-diameter fibers under high O2 pressures. This oxide coating will eventually affect the efficiency of the overall system acting as an electrical insulator and it will increase the interfacial resistance in the cell, lowering the electrochemical performance.
The forming of this oxide coating can be prevented by applying a gold or platinum coating. The surface platinization of titanium generates a coating that is electrically conductive and chemically stable under regular electrolysis conditions. Thereby, extending the lifetime of the titanium, which is ideal for applications that demand high performance and long lifetime. Prevention of the formation of TiO2 will greatly stabilize the electrochemical performance of the electrolyzer or the intended electrochemical device.
• Thickness: 0.010" (10 mils or ~250 micrometers)
• Average pore size: 5-10 micron
• Porosity: ~30%
The following performance curve provides the how well the ultra-thin titanium porous transfer layer does as an anode electrode. The membrane was Nafion 117, anode catalyst was 3.0 mg/cm2 IrRuOx, cathode catalyst was 3 mg/cm2 Pt black and the cell temperature was maintained at 80 deg Celsius. A proprietary hardware was used for this testing and this data may or may not be replicated by other researchers since performance of an electrolysis cell will be a function of the membrane and its thickness, anode and cathode catalysts and their loading, the technique that is used to apply the catalysts to the membrane or the electrode themselves, break-in protocol, design of the testing fixture and sub-components used in the testing fixture, etc.
This product is usually available as in-stock item, otherwise the lead times would be around 4-6 weeks.
Gas Diffusion Layer Properties | |
Porosity | ~ 30% |