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

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 (Ov) 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.