Synthesis of Hollow Spherical Phosphide Catalysts with Industrial-Scale Potential for Alkaline Hydrogen Evolution Reaction

The competitiveness of hydrogen as a fuel of the future relies on the development of low-cost, readily available, and efficient catalysts. Transition metal phosphides (TMP), mainly in multimetallic compositions, are recognized as an excellent alternative to platinum-based catalysts in electrolyzers and fuel cells. Herein, for the first time, the connection of the spray drying method as a user-friendly technique for the large-scale production of TMP as hydrogen evolution reaction (HER) catalysts is presented. Three types of catalysts based on MoFeP modified with Co and Ni as third elements were compared by electrochemical methods in an alkaline medium of 1 M KOH. Among the studied materials, the as-prepared MoFeCoP electrocatalysts exhibited the lowest reaction overpotentials (η₁₀) of −285 mV, with Tafel slopes of 83 mV dec^–1, low activation energy for the HER and sufficient durability in long-term stability tests. The high value of differential capacitance for both trimetallic materials MoFeNiP and MoFeCoP indicates a large surface area, resulting in excellent features for hydrogen production and application.