Rare-earth neodymium doping boosts the catalytic performance of Co3O4 for acidic water oxidation

Developing highly efficient and long-lasting electrocatalysts for the oxygen evolution reaction (OER) in acidic conditions is crucial for advancing proton-exchange membrane water electrolysis (PEMWE) technology. In this work, we present a high-performance OER catalyst by doping the rare-earth element neodymium (Nd) into cobalt oxide (Co 3 O 4 ). The Nd-doped Co 3 O 4 catalyst demonstrates exceptional OER performance, exhibiting an overpotential of merely 304 mV at 10 mA cm −2 in 0.5 M H 2 SO 4 . This performance exceeds that of most non-noble-metal-based catalysts and is comparable to some Ru-based noble-metal catalysts. Furthermore, the catalyst demonstrates excellent long-term stability, maintaining stable performance even after continuous operation in the PEM flow cell for 24 h. Density functional theory (DFT) computations reveal that Nd doping refines the electronic structure of Co 3 O 4 , boosts electrical conductivity, and decreases the energy barriers associated with the formation of crucial OER intermediates. Additionally, the introduction of Nd induces oxygen vacancies and modulates the valence states of cobalt, further enhancing the material's structural stability. This work introduces a novel and effective approach to designing cost-effective, high-performance OER electrocatalysts, providing valuable insights for advancing sustainable energy conversion technologies.