Multi-walled carbon nanotubes (MWNT) activated by nitric acid oxidation were used to prepare supported platinum (1% Pt) catalysts by the excess solution impregnation method. Three different platinum precursors were used to prepare the impregnation solutions, namely diiodo dicarbonyl platinum(II) [PtI2(CO)(2)], dimethyl (1,5-cyclooctadiene) platinum(II) [Pt(CH3)2(C8H12)] and hydrogen hexachloroplatinate(IV) hexahydrate H(2)PtCl(6)center dot 6H(2)O. The catalysts were characterized by transmission electron microscopy (TEM) analysis and H-2 chemisorption. They were tested in the catalytic wet air oxidation (CWAO) of aniline aqueous solutions (200 degrees C and 6.9 bar of oxygen partial pressure). The Pt/MWNT catalyst prepared from H(2)PtCl(6)center dot 6H(2)O showed the best performance with respect to combined activity and selectivity for aniline conversion to non-organic compounds. This catalyst was used in CWAO (150 degrees C and 6.9 bar of oxygen partial pressure) of aqueous solutions of various textile dyes such as the monoazo dye chromotrop 2R (C2R), the diazo dye erionyl red B (ERB) and the triazo dye solophenyl green BLE (SG) 155%. It was found that the selectivity for dye removal decreased in the order diazo > monoazo > triazo. The CWAO of a textile wastewater was also performed using the same catalyst and identical reaction conditions. Complete color removal and 51.2% TOC abatement was obtained under these conditions. (c) 2005 Elsevier B.V. All rights reserved.