Hydrogen induced palladium-based heterojunction electrocatalysts to enhance the oxygen reduction reaction performance

• PdH 0.706 -Pd@CN heterostructure electrocatalysts via a facile method. • H intercalation induces a downshift of the d-band center of Pd in PdH 0.706 -Pd. • Excellent ORR catalytic activity ORR and outstanding Zn-air battery performance. The oxygen reduction reaction (ORR) remains a critical bottleneck in fuel cells and metal-air batteries due to the lack of highly efficient electrocatalysts. Here, we report a simple strategy for synthesizing a palladium-based heterostructured electrocatalyst supported on a carbon nitride matrix (PdH-Pd@CN), which exhibits remarkable ORR activity with a half-wave potential of 0.91 V and excellent durability in 0.1 M KOH. Within the heterostructure, hydrogen intercalation expands the Pd lattice, while interstitial hydrogen doping facilitates charge transfer from Pd to H owing to their electronegativity difference. These synergistic effects modulate the electronic structure, thereby enhancing both activity and stability. When employed in Zn-air batteries, PdH-Pd@CN delivers a maximum power density of 176 mW cm− ( Liu et al., 2025 ) and capacity of 805 mAh g− ( Sun et al., 2021 ) Zn. These findings demonstrate the strong potential of PdH-Pd@CN as an efficient ORR electrocatalyst for next-generation metal-air batteries and related energy technologies.