Catalytic oxidation of volatile organic compounds - Oxidation of methyl-isobutyl-ketone over Pt/zeolite catalysts

The catalytic oxidation of methyl-isobutyl-ketone (MIBK) in low concentration was investigated over several Pt/zeolite catalysts, namely Pt/HEAU(5 and 47) and PUHBEA(50), as well as Pt/gamma-Al2O3, which is the most widely used catalyst for VOC oxidation. The Si/Al ratio of the zeolite was found to be an important parameter for this reaction: catalysts with high Si/Al (i.e., more hydrophobic) present a better performance than those with low Si/Al. On the other hand, the zeolite structure (BEA or FAU) does not have a major influence on the catalyst performance. However, any one of the dealuminated zeolites is a better support than conventional alumina. Pt/HFAU(47) was selected as the most active catalyst. The Pt/HFAU(47) catalyst suffered some deactivation in long duration experiments, probably as a result of coke accumulation. It was found that there is an optimal oxygen partial pressure in the feed: at low oxygen content the accumulated coke compounds are less oxidised; at high oxygen contents platinum oxidation can occur. The presence of water vapour did not have a major effect on the catalyst performance; however, the presence of o-xylene inhibited the oxidation of MIBK, while the oxidation of o-xylene was not affected. (c) 2004 Elsevier B.V. All rights reserved.