Joule-heated PdFe alloys with phase-dependent electronic structures for high-efficiency oxygen reduction

The design of Pd-based alloys with tailored electronic structures and stable architectures is crucial for enhancing catalytic properties. Here, we present a rapid Joule heating strategy for fabricating a palladium-iron (PdFe) alloy anchored on nitrogen-doped carbon (NC–FePd) featuring exceptional performance and durability. By combining ultrafast phase formation and quenching, the NC-FePd system achieves uniform dispersion of cubic-phase FePd₃ nanoparticles with minimized agglomeration. X-ray diffraction and XPS analyses reveal lattice expansion planes and electron transfer between Pd and Fe, which lowers the d-band center of Pd, thereby weakening the Pd–O binding energy. In alkaline media, NC-FePd achieves an exceptional half-wave potential (0.84 V vs. RHE), showing a clear advantage over commercial Pt/C (0.82 V vs. RHE), coupled with elevated limiting current density (6.01 mA cm⁻²) and the diminished Tafel slope (53.73 mV dec⁻¹). This work sheds light on the synergy between rapid Joule-heating synthesis and Fe–Pd electronic modulation for designing durable alloy catalysts.