Metal nanoparticles with a clean surface via clay-nanosheets as stabilizers and supports for catalytic hydrogenation reactions in aqueous-phase

The clean surface of the metal nanoparticles (NPs) plays an important role for their catalysis applications due to more active catalytic sites being available. However, the organic stabilizer is difficultly completely removed for the metal NPs by colloidal preparation. The synthesis of metal NPs without stabilizers requires a suitable solid support as an immobilizer and a proper template to control their shapes. Herein, a general route via clay-nanosheets as both a stabilizer and a support for colloidal synthesis of aqueous soluble metal NPs with a clean surface was proposed. Due to its clean surface and two-dimensional (2D) structure for a great promotion on hydrogenation activity, and Na + ions for promotion on cyclohexanone selectivity, the Pd-NPs showed superior catalytic performance for hydrogenation of phenol to cyclohexanone in water. Ru, Pt and Rh NPs showed superior catalytic performance for hydrogenation of toluene at room temperature and atmospheric pressure.