Effect of the IrO_x Conductivity on the Anode Electrode/Porous Transport Layer Interfacial Resistance in PEM Water Electrolyzers

In this study, a commercial IrO 2 /TiO catalyst (75 wt% Ir, named “Benchmark”) for the oxygen evolution reaction (OER) is compared to newly developed IrO(OH) x (45 “P2X”). Due its lower Ir packing density and higher OER activity vs Benchmark (440 12 A g −1 at 1.43 V iR-free ), P2X shows an improved PEM (proton exchange membrane) water electrolyzer performance ≈9 times reduced loading, however, only if platinum-coated porous transport layer (PTL) anode used. While of membrane electrode assemblies (MEAs) with unaffected when using untreated titanium PTL, MEAs perform poorly, which can be attributed contact resistance anode/PTL interface due low electrical conductivity (0.7 S cm ) (416 passivation Ti-PTL. heat treatment procedure used transform amorphous into crystalline and, hence, increases conductivity. The optimum temperature maximize conductivity, MEA will evaluated.