Proton exchange membrane electrolysis

Proton exchange membrane electrolysis
Diagram of PEM electrolysis reactions.
Typical Materials
Type of Electrolysis:	PEM Electrolysis
Style of membrane/diaphragm	Solid polymer
Bipolar/separator plate material	Titanium or gold and platinum coated titanium
Catalyst material on the anode	Iridium
Catalyst material on the cathode	Platinum
Anode PTL material	Titanium
Cathode PTL material	Carbon paper/carbon fleece
State-of-the-art Operating Ranges
Cell temperature	50-80°C[1]
Stack pressure	<30 bar[1]
Current density	0.6-10.0 A/cm2[1][2]
Cell voltage	1.75-2.20 V[1]
Power density	to 4.4 W/cm2[1]
Part-load range	0-10%[1]
Specific energy consumption stack	4.2-5.6 kWh/Nm3[1]
Specific energy consumption system	4.5-7.5 kWh/Nm3[1]
Cell voltage efficiency	67-82%[1]
System hydrogen production rate	30 Nm3/h[1]
Lifetime stack	<20,000 h[1]
Acceptable degradation rate	<14 μV/h[1]
System lifetime	10-20 y[1]

Proton exchange membrane (PEM) electrolysis is the electrolysis of water in a cell equipped with a solid polymer electrolyte (SPE)^[3] that is responsible for the conduction of protons, separation of product gases, and electrical insulation of the electrodes. 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 dynamic response times, large operational ranges, and high efficiencies, water electrolysis is a promising technology for energy storage coupled with renewable energy sources. In terms of sustainability and environmental impact, PEM electrolysis is considered as a promising technique for high purity and efficient hydrogen production since it emits only oxygen as a by-product without any carbon emissions.^[5] The IEA said in 2022 that more effort was needed.^[6]