Impact of catalyst engineering on the durability performance of self-supported catalysts in anion exchange membrane water electrolyzers: recent advances and perspectives

Developing durable electrodes for anion exchange membrane water electrolyzers (AEMWEs) is crucial for the sustainable and affordable production of green hydrogen. A self-supported catalyst for AEMWEs features a catalytic material directly grown or deposited onto a conductive substrate, such as a metal mesh or foam. This eliminates the need for additional binders while enhancing performance and stability during electrolysis. This direct integration increases the active surface area, boosting current density, and the porous substrate design aids the removal of gas bubbles, thereby improving mass transport. Eliminating binders and establishing in situ growth of active sites on the substrate enhances stability, thus preventing catalyst detachment and improving long-term performance. Recent advancements in the engineering of self-supported catalysts have enhanced the durability of AEMWEs, particularly through strategic modulations such as doping engineering, interface engineering, defect engineering, and morphology engineering. Doping involves the incorporation of foreign atoms to modify electronic properties, which can effectively improve intrinsic conductivity and enhance catalytic activity. Interface engineering creates heterostructures between two or more phases, improving charge transfer and overall catalytic activity. Defect engineering, by introducing controlled vacancies or interstitials, further enhances catalytic sites, providing improved resistance against corrosion and material fatigue during prolonged operation. Meanwhile, morphology tuning allows for the optimization of the surface area and porous structures, which contributes to increased electrolyte penetration and mass transport efficiency. This review highlights that together these strategies represent a holistic approach that researchers are utilizing to develop robust self-supported catalysts that can maintain high performance and durability in AEMWEs.