A highly efficient atomically-thin curved PdIr bimetallene electrocatalyst

The multi-metallene with an ultrahigh surface area has a great potential in precise tuning of surface heterogeneous d-electronic correlation by surface strain effect for the distinctive surface electronic structure, which is a brand new class of promising 2D electrocatalyst for sustainable energy device application. However, achieving such atomically thin multi-metallene still confronts a grand challenge. Herein, we present a new synthetic method for an atomic-level palladium-iridium (PdIr) bimetallene with an average thickness of only ∼1.0 nm for achieving superior catalysis for hydrogen evolution reaction (HER) and formic acid oxidation reaction (FAOR). The curved PdIr bimetallene presents a top-ranked high electrochemical active area of 127.5 ± 10.8 m2 gPd+Ir−1 in the reported noble alloy materials, and exhibits a very low overpotential, ultrahigh activity and improved stability for HER and FAOR. DFT calculation reveals the PdIr bimetallene herein has the unique lattice tangential strain, which can induce the surface distortion with concurrently creating a variety of concave-convex featured micro-active-region formed by variously coordinated Pd-sites-agglomeration. Such strong strain effect correlates the abnormal on-site active 4d10-t2g-orbital Coulomb correlation potential and directly elevates orbital-electronegativity exposing within these active regions, resulting in preeminent barrier-free energetic path for significant enhancement of FAOR and HER catalytic performance.