<p>Interface engineering is a prospective method for improving electrochemical performance, while efficient interfacial tuning is still difficult. Here, a series of WO₃-Ir catalysts with tuned interfaces were obtained from WO₃ support with different surface states. The prepared WO₃-O-Ir catalyst with higher interfacial oxygen content shows excellent hydrogen oxidation reaction activity with a mass activity of 54.04 A g_Ir⁻¹ for hydrogen oxidation reaction, which is superior to WO₃-W-Ir with higher tungsten content and even commercial Pt/C catalysts. Theoretical calculation and X-ray photoelectron spectroscopy valence band spectrum analyses verify that the position of the d-band center is directly proportional to the interfacial oxygen content. This modulates the electronic structure of the active phase, increasing the binding energy for OH species and enhancing their adsorption capacity, which boost the performance for hydrogen oxidation reaction.</p> Graphical Abstract <p></p>