Synthesis of adaptive 15N-nitrosyl-Co7 nanocluster for electrocatalytic C-H functionalization.

Metal nanoclusters have been found to be highly active in catalysis, while balancing their structural stability and catalytic activity remains a key challenge. Herein, we integrate nitrosyl chemistry into nanoclusters to resolve this paradox. Leveraging the adaptive coordination modes of NO ligand, the stability and activity of a Co7 nanocluster are well balanced for electrocatalysis. Particularly, a 15N-labeling approach has been developed to facilitate the structural assignment of the nitrosyl-Co7 nanocluster and its catalytic mechanism investigation. The synthesis of 15N-nitrosyl-Co7 counterpart validates the unique role of cobalt nitrate as both nitrosyl ligand and metal sources, and reveals the synergy between the NO shell and the cobalt core in hydrogen evolution reaction (HER). We redirect the HER activity toward electrocatalytic allene C-H functionalization under high-current-density electrolysis, a transformation that is otherwise inaccessible to conventional metal complex catalysts.