Sp-C coupled geminal-atom facilitate desorption of hydroxyl groups to generate hydrogen

Different from single-atom catalysts, geminal-atom catalysts have been considered as an ideal catalyst capable of facilitating the rapid transformation of complex molecules for their low-valence metal centers and suitable coordination dynamics. Here, we prepared Ru₂ geminal-atom based catalyst (Ru₂-N-GDY) through sp-C confinement method of graphdiyne (GDY). The ultra-close proximity of the geminal-atom Ru sites significantly reduced the hydroxyl adsorption capacity of the two neighbored Ru atoms active sites. Moreover, it has been found that the two neighboring electron-rich sp-C atoms function as H adsorption sites following the adsorption of OH groups on Ru, with the two resulting ∗H species on the sp-C sites being only 1.3 Å apart. As an excellent HER catalyst, this modification dramatically enhances the kinetics of the Tafel step in the HER, achieving a remarkably low Tafel slope of 38 mV dec⁻¹ under alkaline conditions. Benefiting from those, the Ru₂-N-GDY catalyst can achieve rapid water electrolysis and hydrogen production at high current densities, with low overpotentials and ultra-stable operation performance. This study provides a new approach for the rational design of atomic catalysts with high catalytic activity and stability.