Alkaline, PEM, AEM and solid oxide electrolyzers all use electricity to produce hydrogen from water. Their electrolytes, operating conditions and component designs differ, so the materials used inside them also serve different roles.
For a component project, the most useful starting point is to identify the electrolyzer type and the job of the part being developed: electrode, catalyst support, porous transport layer or mechanical support. This guide explains those distinctions and how they relate to nickel and titanium materials.
ALK: liquid alkaline water electrolysis
Conventional alkaline water electrolyzers use an aqueous alkaline electrolyte, commonly based on potassium or sodium hydroxide, with a separator between the electrode compartments. Hydroxide ions carry charge through the electrolyte.
Nickel-based electrodes are widely used in this environment. Mesh, foam and fiber-based structures provide different ways to arrange the conducting framework. A component may function as an electrode itself or support an additional catalytic surface.
HuiRui’s nickel mesh electrolysis guide explains the role of mesh geometry, while the alkaline nickel foam guide looks at open-cell substrates.
PEM: proton exchange membrane electrolysis
PEM electrolyzers use a solid polymer membrane that conducts protons. Water reacts at the anode, and hydrogen is produced at the cathode. The U.S. Department of Energy’s electrolysis overview explains this ion-transport pathway and how it differs from alkaline electrolysis.
In a typical PEM anode assembly, titanium-based porous transport components and an iridium-based catalyst layer have different functions. The porous transport layer provides conducting contact and paths for fluids; the catalyst layer provides the active reaction surface. A titanium felt, a coated titanium substrate and a complete catalyst-coated electrode should therefore be identified separately.
The DOE’s water electrolysis technology assessment discusses titanium transport layers, their interfaces and catalyst materials. For the fibrous material form, see HuiRui’s titanium fiber felt and the guide to titanium felt porosity.
AEM: anion exchange membrane electrolysis
AEM electrolyzers use a polymer membrane that conducts hydroxide ions. They combine a membrane-based cell layout with alkaline electrode chemistry. Nickel and nickel-alloy catalyst materials are among the options discussed in the DOE assessment.
AEM designs can differ in their water or alkaline-electrolyte feed and in the arrangement of the membrane, ionomer and catalyst. Where a nickel substrate is used, it is one part of that assembly. Results for a finished AEM electrode include the effect of these other components and the operating conditions.
SOEC: solid oxide electrolysis
Solid oxide electrolyzers operate with a ceramic electrolyte at elevated temperature. In common oxide-ion-conducting designs, steam reacts at the hydrogen electrode and oxygen ions pass through the ceramic electrolyte. Proton-conducting ceramic variants are also being developed.
The thermal environment and ceramic-cell architecture make SOEC a different materials problem from a low-temperature alkaline or PEM cell. A material described simply as “for hydrogen production” gives too little information to establish a particular role in that assembly.
Operation with renewable electricity
Wind and solar integration depends on the complete electrolyzer system, including its controls and operating range. Alkaline technology can be designed for variable input: a published 2024 alkaline pilot-plant announcement describes tests that simulate fluctuating wind and solar power.
This example supports considering the actual equipment design and operating evidence. Response to changing power, start-stop operation and long-term durability are system-level matters; the choice of a mesh or felt alone does not determine them.
Find the relevant material form
For nickel structures, explore nickel mesh, nickel foam and nickel fiber felt. For porous titanium components, explore titanium fiber felt, titanium woven mesh and titanium foam.
You can contact HuiRui for material information or a quotation.
You’re welcome to contact HuiRui with a short description of your application, preferred material form, or a photo of a sample or drawing. A detailed specification checklist is optional and can be completed later. We can start technical discussion from a simple brief; a final accurate quotation still needs agreed dimensions, quantity and duty conditions — photos alone are not enough for a firm price.
Related reading: Nickel foam, nickel fiber felt or nickel mesh: how to specify the structure.