Bare oxidized carbon nanotubes (CNTs) and carboxylated CNTs treated with sodium carbonate to generate carboxylate groups on the outer surface were used to prepare platinum catalysts by two different methods: incipient wetness and excess solution impregnation. The catalysts were characterized by N-2 adsorption (BET), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), and X-ray fluorescence (XRF). These catalysts were tested in catalytic wet air oxidation of phenol aqueous solutions in a continuous trickle-bed reactor at 2.0 MPa of total pressure and temperatures of 160 and 200 degrees C. The phenol and TOC conversions obtained at steady state were above 94% and 80%, respectively, and the activity per catalyst weight was 30.0 mmol(phenol)center dot gcat(-1)center dot h(-1) in steady-state conditions. This means the first use of CNT in catalytic wet air oxidation of phenol was in continuous trickle-bed reactors (CTBR).