Researchers have tried to further advance the utilization of bimetallic nanoparticles in the field of catalysis due to their high stability, reusability, superior activity, and unique electronic and optical properties as compared with mono-metallic nanomaterials. Moreover, due to the lack of availability and economic viability of mono-metallic nanoparticles, it is necessary to produce highly active ultra-small bimetallic nanoparticles for industrial applications. Cu/Pd bimetallic nanoparticles are synthesized by using a mild hydrothermal one-pot method involving an aqueous solution with hexadecylamine as a capping agent for hydrogenation of aromatic nitro compounds. The synthesized bimetallic Cu/Pd nanoparticles form a cluster of 5±3nm bimetallic particles, and Cu/Pd clusters have been measured to perform the catalytic performance of hydrogenation of 4-nitrophenol, methylene blue, and methyl orange. Cu/Pd nanoparticles have been treated with lactic acid to remove the residual capping agent on the surface, which results in two times better catalytic relay effect between aromatic nitro compounds and NaBH4 in aqueous media than Cu/Pd without lactic acid treatment.