Unraveling the structure-performance relationship of Co-Co/Co-N dual active sites in ZIF-8 derived nitrogen-doped...

Catalytic decomposition is widely recognized as a promising approach for N₂O abatement, yet the rational design of highly active catalysts still remains a huge challenge. In this study, a small Co nanocluster catalyst anchored on a nitrogen-doped carbon framework (Co_x/NC) was constructed via a host-guest encapsulation strategy using ZIF-8 as precursor. The Co_0.09/NC catalyst with Co/2-methylimidazole molar ratio of 0.09 exhibited the best catalytic activity, achieving a T₉₀ of 294 °C and outperforming most reported catalysts. This outstanding catalytic performance was attributed to the synergistic interplay between Co-Co and Co-N coordination. Specifically, the highly dispersed small Co nanoclusters provided abundant Co^2 + active sites for efficient N₂O adsorption and activation, while the peripheral Co-N coordination optimized the d-band center of Co and enhanced electron back-donation. As a result, Co_0.09/NC exhibited significantly lower energy barriers for N-O bond cleavage (0.72 eV) and O₂ formation (1.39 eV) compared to Co_0.3/NC, which suffered from severe Co agglomeration into larger nanoclusters and consequently showed higher barriers (1.09 eV and 2.19 eV, respectively). This work highlighted the importance of Co-Co/Co-N synergy in small nanocluster catalysts and provided a new strategy for the development of highly efficient catalysts for N₂O elimination.