Strong Metal-Support Interaction Between Atomically Dispersed Iridium in Cobalt Phosphide for Efficient Mass/Charge Transfer Synergistically Boosts Overall Water Splitting.

Developing highly efficient bifunctional catalysts is essential for advanced green hydrogen production technologies. However, achieving lower energy barriers and improving mass/charge transfer kinetics remains a significant challenge for enhancing electrocatalytic performance. Herein, a novel dual-atom interaction strategy is proposed, featuring an Ir-Co phosphide heterostructure (IrCo50P@C) embedded in MOF-derived porous carbon, which influences interfacial synergy and tailored electronic interactions to optimize hydrogen adsorption and enhance reaction kinetics, thus significantly boosting HER and OER activity under alkaline media. DFT simulations collectively prove that when synergistically integrated with the CoP@C support, Ir doping enhances mass and charge transport, modulates the d-band center to reduce energy barriers, and significantly improves catalytic kinetics. The IrCo50P@C catalyst demonstrates excellent bifunctional electrocatalytic performance, achieving a minimal overpotential of 14 and 17 mV (Pt/C) for HER and 251 and 271 mV (Ir/C) for OER at 10 mA cm-2. Amazingly, the IrCoP@C based electrode integrated water electrolyzer exhibits low-voltage operation of 1.505 and 1.806 V to achieve 10 and 100 mA cm-2 with excellent operational stability over 120 h, respectively. The phosphidation-induced electron deficiency and facilitated electron hopping present a viable strategy for designing next-generation electrocatalysts with superior activity and operational stability.