Search results
Results from the WOW.Com Content Network
Alkaline water electrolysis is a type of electrolysis that is characterized by having two electrodes operating in a liquid alkaline electrolyte. Commonly, a solution of potassium hydroxide (KOH) or sodium hydroxide (NaOH) at 25-40 wt% is used. [ 6 ]
The PEM electrolyzer was introduced to overcome the issues of partial load, low current density, and low pressure operation currently plaguing the alkaline electrolyzer. [4] [1] It involves a proton-exchange membrane. Electrolysis of water is an important technology for the production of hydrogen to be used as an energy carrier. With fast ...
Alkaline electrolyzers are cheaper in terms of investment (they generally use nickel catalysts), but least efficient. PEM electrolyzers are more expensive (they generally use expensive platinum-group metal catalysts) but are more efficient and can operate at higher current densities, and can, therefore, be possibly cheaper if the hydrogen ...
Ultrahigh-pressure electrolysis is high-pressure electrolysis operating at 340–690 bars (5,000–10,000 psi). [8] At ultra-high pressures the water solubility and cross-permeation across the membrane of H 2 and O 2 is affecting hydrogen purity, modified PEMs are used to reduce cross-permeation in combination with catalytic H 2 /O 2 recombiners to maintain H 2 levels in O 2 and O 2 levels in ...
A water ionizer (also known as an alkaline ionizer) is a home appliance which claims to raise the pH of drinking water by using electrolysis to separate the incoming water stream into acidic and alkaline components. [1] [2] [3] The treated water is called alkaline water.
The alkaline fuel cell used by NASA in 1960s for Apollo and Space Shuttle program generated electricity at nearly 70% efficiency using aqueous solution of KOH as an electrolyte. In that situation, CO 2 coming in through oxidant air stream and generated as by product from oxidation of methanol, if methanol is the fuel, reacts with electrolyte ...
A membrane electrode assembly (MEA) is an assembled stack of proton-exchange membranes (PEM) or alkali anion exchange membrane (AAEM), catalyst and flat plate electrode used in fuel cells and electrolyzers. [1] [2]
PEMFCs are built out of membrane electrode assemblies (MEA) which include the electrodes, electrolyte, catalyst, and gas diffusion layers. An ink of catalyst, carbon, and electrode are sprayed or painted onto the solid electrolyte and carbon paper is hot pressed on either side to protect the inside of the cell and also act as electrodes.