Single Carbon Vacancy Traps Atomic Platinum for Hydrogen Evolution Catalysis.

The coordinated configuration of atomic platinum (Pt) has always been identified as an active site with high intrinsic activity for hydrogen evolution reaction (HER). Herein, we purposely synthesize single vacancies in a carbon matrix (defective graphene) that can trap atomic Pt to form the Pt-C ₃ configuration, which gives exceptionally high reactivity for HER in both acidic and alkaline solutions. The intrinsic activity of Pt-C ₃ site is valued with a turnover frequency (TOF) of 26.41 s ^-1 and mass activity of 26.05 A g ^-1 at 100 mV, respectively, which are both nearly 18 times higher than those of commercial 20 wt % Pt/C. It is revealed that the optimal coordination Pt-C ₃ has a stronger electron-capture ability and lower Gibbs free energy difference (Δ G ), resulting in promoting the reduction of adsorbed H ⁺ and the acceleration of H ₂ desorption, thus exhibiting the extraordinary HER activity. This work provides a new insight on the unique coordinated configuration of dispersive atomic Pt in defective C matrix for superior HER performance.