Alkaline hydrogen evolution on CO-M@gCN dual-atom catalysts: insights from first-principles calculations

Dual-atom catalysts (DACs) offer unique opportunities for enhancing electrocatalytic performance through synergistic metal interactions. Herein, we employ spin-polarized density functional theory to investigate Co-M DACs (M = Cr, Mn, Fe, Co, Ni, Cu, Pd, Ru, Ir, Pt) supported on graphitic carbon nitride (gCN) for the hydrogen evolution reaction (HER) in alkaline media. Among the examined systems, CoCr@gCN demonstrates the best performance with a low water dissociation barrier (0.42 eV), nearly thermoneutral hydrogen adsorption (ΔGH* ≈ 0.03 eV), and half-metallic behavior. Electronic descriptors such as iCOHP, Bader charge, and a φ parameter based on metal properties help elucidate activity trends. Systems with φ in the range of 4.5-4.6 exhibit enhanced catalytic properties. Ab initio molecular dynamics simulations confirm the thermal stability of CoCr@gCN at 400 K. This work provides insights into the design of efficient and earth-abundant DACs for sustainable hydrogen production.