We've spoken already about Gas Diffusion Layer (GDL) selection for a Fuel Cell; today we will cover some GDL considerations for Electrolyzers.
Why is an activation procedure or break-in necessary for a membrane electrode assembly (MEA)? A large reason for performing an activation procedure or break-in is to properly humidify the membrane portion of the MEA that was dried out during the hot press stage of the membrane electrode assembly (MEA) production. MEAs will not work well when they are not fully humidified (see article: Why is Humidity / Moisture Control Important in a Fuel Cell?).
How do I Humidify a Membrane Electrode Assembly (MEA)?
You can re-humidify the MEA by soaking it in deionized water. ..
PEM electrolyzers convert water and power into hydrogen and oxygen. In this article, we will focus on the principles behind an electrolyzer. Everything below refers primarily to PEM electrolyzers, but much of it can be applied to other types of electrolyzers as well. The spreadsheet linked at the bottom of this article will help you determine the cell voltage, efficiency, and output rate of hydrogen and oxygen of your electrolyzer.
The rate of ion exchange depends on the rates of the chemical (ionic) reactions in the ionic exchange material (membranes, dispersions, beads, pellets, etc.), but it is often limited by the diffusion processes. The ion exchange process maybe primarily controlled by diffusion, which is dependent upon the material layers, structure, thickness and reactant rate of contact on the surface of the material. This blog post introduces the factors to consider when thinking about the kinetics of the ion exchange reactions.
Mechanism of Ion Exchange Processes
A common ion-exchange system is an ..
Ion exchange materials are used to purify, separate, and extract many different types of molecules, including organic and biochemical molecules. When ion exchange materials involve these ion types, there may be additional complexities involved with the interaction.Some of the phenomena that may occur are:
Secondary forces between the ionized group and counterion. These forces may consist of coordination, hydrogen, and van der Waals bonding.
The pH can affect the percent ionization.
The position of the functional groups can affect ion transport.
Hydration of organic molecules can be more complex than inorganic ions.
Organic ions may be larger than inorganic ions; thus, steric hinderances can reduce ionic interactions.
Therefore, ion exchange phenomena may be able to be explained chemically by stoichiometric reactions, but the actual ionic selectively may be determined by other interactions.
Membranes are essential for PEM fuel cells to operate. The Proton Exchange Membrane carries the hydrogen ions from the anode to the cathode without passing the electrons that were removed from the hydrogen atoms.
The Fuel Cell Store carries the largest selection of Membranes in the world! We help you compare all the Membranes we offer in one simple file so you can narrow down the perfect Membrane for your project. With our Membrane Comparison Table you can compare the specifications of all our Cation Exchange Membranes, Anion Exchange Membranes, and Bipolar Membranes with ease.
Cation exchange membranes (CEMs) are frequently referred to as proton exchange membranes (PEMs) because they are often used in chemical reactions that generate protons. CEMs are used in various applications ranging from proton exchange membrane and microbial fuel cells to chlorine and caustic soda production. The cation exchange membrane (CEM) contains negatively charged functional groups (PO3-, COO–, and C6H4O–) in the membrane backbone, which allows cations to pass through. There are many types of CEM that have been used in the literature, including Nafion©, Fumatech, Aquiv..
Zero-gap electrolyzers are similar to fuel cells in design because the heart of the electrolyzer consists of two electrodes pressed against a membrane. These electrolyzers are called “zero-gap” because there is no gap between the cathodes, anodes, and the electrolyte. This design decreases the distance for ion transport because the layers are pressed or bonded together. The zero-gap CO2 electrolyzers can achieve high current densities (≥100 mA/cm2) by delivering gaseous CO2 to the cathode. The efficiency of these electrolyzers depends upon the catalysts used, the operating conditions, and o..
An Introduction to CO2 Capture and Conversion
Electrochemical devices that convert CO2 into fuels and valuable compounds have been undergoing extensive research for over a decade now. The research in this area has been driven by the desire to reduce reliance on fossil fuels and reduce greenhouse emissions. As you are probably aware, the majority of the world’s energy used for transportation, industrial, and residential uses are made from coal, petroleum, and natural gas.
An Increase in CO2 Emissions
As we are all aware, the consumption of fossil fuels has led to an increase in C..
Ion-exchanges membranes (IEMs) have many applications beyond fuel cells -- they can also be used to synthesize all types of compounds that are used in various industries. The most popular IEMs consist of polymeric resins with charged functional groups based upon their ion selectivity, they are referred to as anion-exchange (AEM) and...