Nanocomposite Electrodes and Membranes for PEM Electrolysis
Authors: Cavaliere Sara , Jiménez-Morales Ignacio , Al Cheikh Joumada , Jones Deborah J. , Rozière Jacques 
Published: September 2023

Reducing the iridium loading while keeping high mass activity and durability is one of the greatest challenges for PEMWE development.[1] Amongst the strategies to achieve this central goal, supporting iridium oxide on metal oxide supports offers high resistance to corrosion as well as electronic electrocatalyst-support interactions beneficial for catalyst activity and durability.[2] The morphology of the supports also plays a crucial role in the control of architecture and porosity of the catalyst layers.
Here, tin oxide materials doped with aliovalent ions (niobium, antimony and tantalum)[3,4] were prepared by electrospinning leading to a fibre-in-tube morphology. The doping led to increase of the intrinsically low electrical conductivity of the semiconductor oxide. The electrochemical stability of the different supports was evaluated in acidic medium at low and high potentials, coupling electrochemistry and spectroscopic methods.[5] IrO2 nanoparticles synthesized by a microwave-assisted polyol method were deposited onto the doped SnO2 nanomaterials. Their electrochemical activity towards the oxygen evolution reaction (OER) as well as their durability upon accelerated stress tests were evaluated.
In order to enhance the PEMWE performance, the use of thin membranes reducing resistive effects is crucial. To avoid premature failure and gas permeability issues, reinforcing polymer nanofibrous webs were introduced in the PFSA matrix.[6] The nanocomposite membranes obtained led to greater mechanical robustness and reduced gas crossover while keeping high proton conductivity. [7]
The nanocomposite electrocatalysts and membranes were used to prepare membrane-electrode assemblies and characterised in a PEMWE cell. Their performance and stability were investigated in different operating conditions and will be discussed.

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