Surface Single-Cluster Catalyst for N_2-to-NH_3 Thermal Conversion

摘要

The ammonia synthesis from N_(2) is of vital importance, with imitating biological nitrogen fixation attracted much interest. Herein, we investigate the catalytic mechanisms of N_(2)-to-NH_(3) thermal conversion on the singly dispersed bimetallic catalyst Rh_(1)Co_(3)/CoO(011), and find that the preferred pathway is an associative mechanism analogous to the biological process, in which alternating hydrogenations of the N_(2) occur, with H_(2) activation on both metal sites. We propose that the singly dispersed bimetallic M_(1)A_( n ) 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 N_(2)-to-NH_(3) thermal conversion. The catalytic ability of M_(1)A_( n ) 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 M_(1)A_( n ) catalyst.