Vanadium supported on carbon coated honeycomb monoliths for the selective catalytic reduction of NO at low temperatures:: Influence of the oxidation pre-treatment

Mesoporous carbon-ceramic honeycomb monoliths were prepared for catalyst supports by a polymer blend approach. In these monoliths, vanadium was supported by ion exchange of the cationic precursor with the protons of oxygenated surface groups. Previously to vanadium incorporation, the carbon-ceramic monoliths were oxidized using different agents under various conditions to get different oxidation degrees. The texture and surface chemistry of the as-prepared carbon-ceramic monolithic supports were exhaustively characterized by N-2 physisorption, Fourier transform infrared spectroscopy, temperature programmed decomposition and photoelectron spectroscopy. The resulting vanadium on carbon coated monoliths were tested in the selective catalytic reduction of NO with NH3 at 453 K. The chemical and textural characterization of the samples after the different oxidation treatments revealed some of the reasons leading to a higher vanadium loading and dispersion. Among the oxidation treatments used, that with 10% O-2 at 603 K gave rise to the highest vanadium loading and a high dispersion. Treatments with HNO3 also brought about high vanadium dispersion while that with ozone led to the lowest dispersion. It was observed that vanadium loading did not only depend on the amount of oxygen-containing groups but also on the textural properties resulting after the oxidation treatment. (C) 2005 Elsevier Ltd. All rights reserved.