Fig. 5. PEMWE device performance using AC-MoRuO_x as an acidic OER catalyst in a 0.1 M HClO₄ electrolyte at 80°C.

(A) Schematic diagram of the PEM electrolyzer, a typical single PEMWE setup comprising a MEA and bipolar plates (BPs) with a flow field presented, wherein the MEA comprises gas diffusion layers with a Ti felt and a carbon paper (CP) at the anodic and cathodic sides, respectively; anodic and cathodic catalyst layers; and a PEM. (B) Polarization curves of the PEM electrolyzers using AC-MoRuO_x or Com RuO₂ as the anode catalyst and Com Pt/C as the cathodic catalyst at 80°C. (C to E) Chronopotentiometry curve of the PEM electrolyzer using AC-MoRuO_x and Com RuO₂ nanocatalysts operated at 200 mA cm⁻² (C), 1000 mA cm⁻² (D), and 1500 mA cm⁻² (E). The small fluctuations in cell voltage might be caused by the generation of bubbles that could not dissipate from the surface of MEAs. (F) Performance comparison of the PEM electrolyzer activity and stability of AC-MoRuO_x with those of previously reported state-of-the-art catalysts.