Supported metal pair sites have sparked interest due to their tremendous potential as bifunctional catalysts. Here, we report the structural Ni0–Niδ+ pair sites constructed in a well-defined nanocrystal phase of Ni3P. These Ni0–Niδ+ pair sites exhibited a remarkable product formation rate of 123 molBA/molmetal/h for the hydrogenation of benzonitrile (BN) to benzylamine (BA). The heterogeneity of surface Ni atoms over the Ni3P crystal created two types of metal centers, Ni0 and Niδ+, with a specific spatial distance of 4–5 Å. The Ni0 site acted as the center for H2 activation, while the Niδ+ site served as the adsorption and activation center for the C ≡ N group. The highly efficient cooperation effect of Ni0–Niδ+ pair sites resulted in a TOF of 2915 h–1 in BN hydrogenation, which is 2.4 and 9.7 times higher than that over the mono-Ni0 and -Niδ+ sites, respectively.