Controllable synthesis of a Pd/PdO nanocomposite as a catalyst for hydrogenation of nitroarenes to anilines in water

A heterogeneous catalytic assembly of the different Pd/PdO ratio nanoparticles supported on oxide carbon nanotubes (OCNTs) can be controllably synthesized by a one-pot gas-liquid interfacial plasma (GLIP) method via adjusting the glow produced parameter. The Pd/PdO nanoparticles have uniform particle size distribution. It is found that the catalysts with different Pd/PdO ratios could affect catalytic activity during the reduction of 4-nitrophenol (4-NP) in water by NaBH4. The best turn over frequency (TOF) value is up to 3000 h(-1), which is much higher than the case only using Pd nanoparticles as catalysts. Moreover, the catalysts allowed hydrogenation of nitroarenes in water by atmospheric pressure H-2, and it displayed remarkable activity toward the hydrogenation of nitroarenes using low Pd loading in good yields. The catalyst can be simply and efficiently used for ten consecutive runs without significant decrease in activity.