In this work, N-doped reduced graphene oxides (NRGO) was synthesized via a facile urea-hydrothermal treatment of graphene oxide and used as support for ultrafine Pd nanoparticles (NPs). It was found that N in NRGO can improve the dispersion of Pd NPs. NRGO supported Pd catalyst (Pd/NRGO) is highly active and selective for the hydrogenation of C=C bond in cinnamaldehyde and hydrogenation of phenol to cyclohexanone under mild conditions. X-ray diffraction, X-ray photoelectron spectra and transmission electron microscopy characterizations confirmed the interaction between NRGO and Pd enhanced with the amount of N atom in NRGO. Raman spectroscopy of adsorbed cinnamaldehyde on Pd/NRGO suggested that NRGO played a positive role in the selective activation of C=C bond in cinnamaldehyde. (C) 2015 Elsevier B.V. All rights reserved.