Electronic metal–support interaction induces electron deficiency in iridium for promoted ampere-grade-current-density electrocatalytic hydrogen evolution

Precise manipulation of the metal-support interaction offers a powerful approach for tailoring the electronic properties of electrocatalysts and driving superior hydrogen evolution reaction (HER) performance. However, achieving high catalytic performance at ampere-level current densities remains a formidable challenge. Herein, an iridium-cobalt phosphide heterostructure anchored on carbon nanofibers (Ir-CoP/CNFs) is constructed to boost the electrocatalytic HER performance. In this catalyst, the electronic metal-support interaction (EMSI) induces an electron deficiency in Ir, which modulates its electronic structure and effectively mitigates excessive H* intermediate adsorption. This electronic modulation greatly reduces the energy barrier for water dissociation, endowing the catalyst with exceptional alkaline/acidic-universal HER activity. Remarkably, the Ir-CoP/CNFs catalyst presents higher HER activity than Pt/C at ampere-grade current density, achieving overpotentials of merely 117 mV in 0.5 M H₂SO₄ and 235 mV in 1.0 M KOH at 1000 mA cm^-2. These values rank among the best-reported performance for HER electrocatalysts. Moreover, this catalyst also demonstrates superior durability compared to Pt/C. This study underscores the impact of EMSI on enhancing HER performance at high current densities, paving the way for the development of high-efficiency next-generation HER electrocatalysts.