Surface Single-Cluster Catalyst for N₂-to-NH₃ Thermal Conversion

The ammonia synthesis from N₂ is of vital importance, with imitating biological nitrogen fixation attracted much interest. Herein, we investigate the catalytic mechanisms of N₂-to-NH₃ thermal conversion on the singly dispersed bimetallic catalyst Rh₁Co₃/CoO(011), and find that the preferred pathway is an associative mechanism analogous to the biological process, in which alternating hydrogenations of the N₂ occur, with H₂ activation on both metal sites. We propose that the singly dispersed bimetallic M₁An catalyst, in which the doped metal atom M substitutes an oxygen atom on the oxide surface of metal A, serves as a new surface single-cluster catalyst (SCC) design platform for the biomimetic N₂-to-NH₃ thermal conversion. The catalytic ability of M₁An catalyst is attributed to both the charge buffer capacity of doped metal M and the complementary role of synergic metal A in catalysis. Our work provides insights and guidelines for further optimizing the M₁An catalyst.