Surface reaction-induced LaBO3 nano-islands confine dispersed Ni species for highly efficient NH3 decomposition

NH₃ decomposition is receiving increased attention for on-site CO_x-free H₂ generation. Unfortunately, the harsh reaction conditions often cause sintering of active metals. Here we report a simple method to achieve well Ni dispersion by nano-structuring the BN support with La species. The surface reaction-induced LaBO₃ nano-islands on BN support have a strong affinity for Ni atoms, which can capture and confine Ni species to yield a large population of well dispersed Ni clusters and nanoparticles. The Ni species selectively anchored on LaBO₃ islands expose more active sites and boost desorption of N₂ and H₂, exhibiting superior activity and stability for NH₃ decomposition. In addition, it is revealed that the Ni dispersion is sensitive to the change of the support surface structure. These findings highlight the important role of support structure in determining the nature of the metal phase and provide guidance for designing catalysts with controlled catalytic structure and reactivity.