Phosphorus‐Enhanced Synergistic Effects in Bimetallic Single‐Atom Catalysts for the Electrochemical Hydrogen Evolution Reaction: A DFT Study

Single‐atom catalysts (SACs) offer maximum atomic efficiency and well‐defined active sites, yet their limited coordination environment often restricts performance in multistep redox reactions. To overcome this, phosphorus‐bridged bimetallic SACs featuring dual‐metal centers (transition metal (TM) 1─P─TM2) are designed and computationally screened for electrocatalytic water splitting and hydrogen storage. Using spin‐polarized density functional theory, their thermodynamic and kinetic performances are evaluated through adsorption free energies, binding energies, and electronic descriptors. Thermal stability is further confirmed through ab initio molecular dynamics simulations at 300 K under a Nosé–Hoover thermostat. Among the studied hydrogen evolution reaction (HER) catalysts, the Mn─P─Fe (Mn) catalyst at the Mn active site exhibits nearly ideal HER activity (Δ G H* = 0.09 eV). Notably, the V─P─Cr (V‐site) catalyst shows favorable hydrogen storage capacity (3.31 wt%). Furthermore, solvation effects are examined using implicit, explicit, and hybrid models via Vienna Ab initio Simulation package solvation and their kinetics evaluated by electronic descriptors to more accurately predict adsorption energies under aqueous conditions.