Novel Pt catalysts supported on undoped and N-doped (1% N, w) carbons with well interconnected and nanostructured mesoporosity (V-mesopore = 0.65 cm(3)g(-1), S-EXT = 730 m(2) g(-1)) were prepared and tested in the hydrodechlorination of 4-chlorophenol in water at 30-70 degrees C. The growth of Pt nanoparticles was achieved using incipient wetness impregnation and a modified colloidal synthesis. Total conversion of 4chlorophenol and 100% selectivity to cyclohexanol was achieved. The remarkable activity in the hydrogenation of the phenol resulting from hydrodechlorination has not been reported before with Pt catalysts and it is of high interest because it maximizes detoxification. When the Pt NPs were synthesized by incipient wetness impregnation some influence of the N-doping of the support was observed in the size and electronic state of the NPs. However, highly reproducible Pt NPs were prepared by in situ colloidal synthesis regardless the nature of the support. In this last case similar activity was observed for the catalysts with undoped and N-doped carbon support, although the activity increased more with temperature for the later. Apparent activation energies of 15-25 kJ mol(-1) were obtained for the disappearance of 4-chlorophenol.