479 resultados para Spent catalyst
Resumo:
A highly active catalyst, MnOx/TiO2-Al2O3, was prepared by impregnating MnOx species on TiO2-modified Al2O3. The TiO2 species in TiO2-Al2O3 support is in a monolayer dispersion, and the MnOx species is again highly dispersed on TiO2-Al2O3 Support. The total oxidation of chlorobenzene and o-dichlorobenzene on MnOx/TiO2-Al2O3 catalyst can be achieved at 300 degreesC and 250 degreesC respectively, at the space velocity of 8000 h(-1). The activity of MnOx/TiO2-Al2O3 catalyst (Mn loading 11.2 wt%) is gradually increased in the first 10-20 h and then keeps stable at least for the measured 52 h at 16,000 h(-1). Furthermore, no chlorinated organic byproducts are detected in the effluent during the oxidative destruction of chlorobenzene and o-dichlorobenzene. It is proposed that the partially chlorinated and highly dispersed manganese oxide on a monolayer TiO2-modified Al2O3 is responsible for the high and stable activity for the total oxidation of chlorinated aromatics. (C) 2001 Academic Press.