Showing papers by "José J.M. Órfão published in 2005"
TL;DR: The surface chemistry of the activated carbon is an important parameter; it was observed that basic samples improve TOC removal and the combination of activated carbon with ozone enhanced the decolouring of the solutions and especially the mineralisation of the organic matter.
123 citations
TL;DR: In this article, the authors investigated the performance of several Pt/zeolite catalysts for methyl-isobutyl-ketone (MIBK) in low concentration.
Abstract: The catalytic oxidation of methyl-isobutyl-ketone (MIBK) in low concentration was investigated over several Pt/zeolite catalysts, namely Pt/HFAU(5 and 47) and Pt/HBEA(50), as well as Pt/γ-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.
105 citations