Catalytic combustion of benzofuran and of a benzofuran/1,2-dichlorobenzene binary mixture over zeolite catalysts

The catalytic combustion of benzofuran and of benzofuran/1,2-dichlorobenzene binary mixture over zeolite catalysts was investigated. The benzofuran is much easier to oxidize compared to chlorinated aromatic compounds and PtNaY is the most adapted catalyst for this oxidation reaction. Unfortunately, in the presence of the benzofuran/1,2-dichlorobenzene mixture, PtNaY catalyst deactivates and becomes less adapted for oxidation reaction than a catalyst based on acid zeolite like HY (Si/Al = 5). Thus, PtHY proved to be a promising catalyst for 1,2-dichlorobenzene mixture degradation. The presence of benzofuran in mixture clearly improves the conversion of chlorinated compound, decreases the production of chlorinated by-products and enhances the selectivity into CO2.The oxidation of benzofuran/1,2-dichlorobenzene mixture is also influenced by the platinum content deposited on zeolite, the activity of PtHY catalyst increasing linearly with the platinum level. Thus, at 350 °C, the 1.2% PtHY catalyst is able to completely oxidize the 1,2-dichlorobenzene in mixture into CO2 with production of a low amount of PhClx by-products.Deactivation has been studied on 1.2% PtHYcatalyst, catalyst initially deactivates during the first 24 h reaction. The main cause of this initial deactivation is certainly a Pt sintering leading to a collapse of the cristallinity of the zeolite. However, after 24 h reaction PtHY catalyst was stable and allows to oxidize 1,2-dichlorobenzene with a limited formation of polychlorobenzene by-products.