Nickel–Molybdenum Nanoparticles Anchored on Molybdenum Oxide as High-Performance Electrocatalyst for Hydrogen Production in Alkaline Water Electrolysis
Anna Katharina Müller, Stefan Loos, Christian Immanuel Bernäcker, Aaron B. Naden, Felix Heubner, Thomas Weißgärber
Abstract
High Resolution Image Download MS PowerPoint Slide The development of efficient and cost-effective electrocatalysts for alkaline water electrolysis is crucial for advancing hydrogen production technologies. Herein, we report the synthesis and characterization of a highly active, platinum-group-metal-free electrocatalyst for the hydrogen evolution reaction in alkaline media. The catalyst is obtained via the exsolution of Ni–Mo alloy nanoparticles anchored on MoO 2 during the reduction of a NiMoO 4 precursor grown on porous nickel substrates. It demonstrates high catalytic activity, achieving benchmark performance with an overpotential of −89 mV and a cell voltage of 1.71 V at a current density of 1 A/cm 2 . Electrochemical testing, including operation at high current densities under industrially relevant conditions (80 °C, 30 wt % KOH, flowing electrolyte), validates its suitability for large-scale applications. Importantly, structural analysis reveals the presence of Ni-rich Ni 10 Mo particles on MoO 2 rather than the often-proposed Ni 4 Mo alloy, providing insight into the actual active phase of Ni–Mo catalysts. This distinction advances the fundamental understanding of Ni–Mo chemistry and offers guidance for the rational design of high-performance, platinum-group-metal-free catalysts for hydrogen evolution.