Insight to the Catalytic Activity of Atomically Precise Ag₄Ni₂ Nanoclusters on Silicon Carbide for Nitroarene Reduction

Abstract

Atomically precise Ag 4 Ni 2 nanoclusters with 2,4dimethylbenzenethiol as the ligands were synthesized and characterized as a cocatalyst of SiC for the selective hydrogenation of nitroarenes to arylamine in the presence of NaBH 4 . The obtained Ag 4 Ni 2 /SiC samples exhibited extraordinary catalytic activity, and a self-accelerated catalytic process was observed with the reduction of nitrophenol to aminophenol as the model reaction. Experimental comparison between the Ag 4 Ni 2 /SiC samples before and after the catalysis showed that the transformation of Ag 4 Ni 2 clusters to polydisperse Ag particles as well as amorphous NiO x on the surface of SiC in the catalysis was the key to their high activity. AIMD calculations revealed that the transformation of Ag 4 Ni 2 was driven by the presence of multiple hydrides on the cluster, which induced the detachment of the thiol ligand of the nanoclusters.