Preparation of Pr₂O₃-Co₃Fe₇ dual-active components co-embedded in nitrogen-doped carbon and investigation of alkaline...

The hydrogen evolution reaction (HER) is a key half-reaction in electrocatalytic water splitting for hydrogen production that is limited by slow water dissociation kinetics in alkaline media. Therefore, developing high-performance nonprecious metal electrocatalysts for alkaline HER is crucial for sustainable energy conversion. In this study, a series of composite electrocatalysts with Pr₂O₃ and Co₃Fe₇ nanoparticles co-embedded in nitrogen-doped carbon (NC) were designed and synthesized via simple hydrothermal and pyrolysis processes. Among these catalysts, the 1.0Pr₂O₃/Co₃Fe₇/NC catalyst exhibits an overpotential of 198 mV and a Tafel slope of 95.17 mV dec^-1 under alkaline conditions at a current density of -10 mA cm^-2. Multiple characterization results indicate that the improvement in HER activity results from synergistic effects in the multicomponent system. An appropriate amount of the Pr₂O₃ phase provides abundant oxygen vacancies (O_v) for the catalyst and promotes the enrichment of Co²⁺/Fe²⁺ species, which are crucial for water dissociation during hydrogen evolution. This study clarifies the crucial role of rare-earth oxides in stabilizing the valence states of active metals and promoting synergistic catalysis among multiple components. It provides new insights into the design of advanced composite electrocatalysts.