Anion exchange membrane (AEM) electrolysis is hampered by two main issues: stability and performance. Focusing on the latter, this work demonstrates a highly active NiMo cathode for hydrogen evolution in AEM electrolysis. We demonstrate an electrolyzer performance of 1 A cm⁻² at 1.9 V (total cell voltage) with a NiMo loading of 5 mg cm⁻² and an iridium black anode in 1 M KOH at 50 °C, that may be compared to 1.8 V for a similar cell with Pt at the cathode. The catalysts developed here will be significant in supporting the pursuit of cheap and environmentally friendly hydrogen fuel.

Anion exchange membrane water electrolysis (AEMWE) is an efficient, cost-effective solution to renewable energy storage. The process includes oxygen and hydrogen evolution reactions (OER and HER); the OER is kinetically unfavourable. Studies have shown that nickel (Ni)- iron (Fe) catalysts enhance activity towards OER, and cerium oxide (CeO₂) supports have shown positive effects on catalytic performance. This study covers the preliminary evaluation of Ni, Ni₉₀Fe₁₀ (at%) and Ni₉₀Fe₁₀/CeO₂ (50 wt%) nanoparticles (NPs), synthesized by chemical reduction, as OER catalysts in AEMWE using commercial membranes. Transmission electron microscopy (TEM) images of the Ni-based NPs indicate NPs roughly 4–6 nm in size. Three-electrode cell measurements indicate that Ni₉₀Fe₁₀ is the most active non-noble metal catalyst in 1 and 0.1 M KOH. AEMWE measurements of the anodes show cells achieving overall cell voltages between 1.85 and 1.90 V at 2 A cm⁻² in 1 M KOH at 50 °C, which is comparable to the selected iridium-black reference catalyst. In 0.1 M KOH, the AEMWE cell containing Ni₉₀Fe₁₀ attained the lowest voltage of 1.99 V at 2 A cm⁻². Electrochemical impedance spectroscopy (EIS) of the AEMWE cells using Ni₉₀Fe₁₀/CeO₂ showed a higher ohmic resistance than all catalysts, indicating the need for support optimization.