A highly efficient two-dimensional (2D) nanocatalyst for the aerobic oxidation of amines, consisting of ruthenium-exfoliated molybdenum disulfide (Ru@E-MoS2), was investigated. As-synthesized Ru@E-MoS2 yielded the nitriles from various aromatic, aliphatic, allylic, and heteroatomic amines with high selectivity in molecular oxygen as terminal oxidants. The Ru@E-MoS2 experienced an improved catalytic activity for benzylamine and p-substituted benzylamine derivatives and produced good turnover numbers (TONs) for aliphatic amines. Moreover, the heterogeneous Ru@E-MoS2 nanocatalyst maintained its catalytic performance for five cycles of benzylamine oxidation reaction.