A series of materials featuring CuO and(or) V2O5 supported on TiO2, Al2O3, or a composite Al2O3-TiO2 carrier was tested for suitability as sorbents/catalysts for the simultaneous removal of SO2 and NOx from flue gases. SO2 sorption at 300° was assocd. with the formation of CuSO4 and some Al2(SO4)3, the latter via a bridging Cu-SO4-Al surface species. Only part of the sorption capacity could be regenerated by redn. in H at 450°. Selective catalytic redn. of NO by NH3 over CuO/TiO2, CuO/Al2O3-TiO2, and CuO/Al2O3 was decreased following exposure of the catalysts to SO2, and this feature was attributed to competition for NH3 between NO and surface sulfate species, the latter involving formation of (NH4)2SO4. V2O3 supported on a composite support featuring 20% AL2O3, balance TiO2, was as active as V/TiO2 for NO redn. by NH3, and the Al2O3 component rendered the catalyst resistant to SO2 poisoning because sulfate formed on V2O5 could be transferred to Al2O3, where it did not interfere with the activity. Catalysts with CuO and V2O5 supported on Al2O3-TiO2 were not resistant to SO2 poisoning during selective catalytic redn. of NO because the Cu component attracted too much SO2 onto the support, thus exceeding the protective capacity of the Al2O3 component. [on SciFinder(R)]
Assessment of copper-vanadium oxide on mixed alumina-titania supports as sulfur dioxide sorbents and as catalysts for the selective catalytic reduction of nitrogen oxides (NOx) by ammonia
CENTI, Gabriele;PERATHONER, Siglinda;
1992-01-01
Abstract
A series of materials featuring CuO and(or) V2O5 supported on TiO2, Al2O3, or a composite Al2O3-TiO2 carrier was tested for suitability as sorbents/catalysts for the simultaneous removal of SO2 and NOx from flue gases. SO2 sorption at 300° was assocd. with the formation of CuSO4 and some Al2(SO4)3, the latter via a bridging Cu-SO4-Al surface species. Only part of the sorption capacity could be regenerated by redn. in H at 450°. Selective catalytic redn. of NO by NH3 over CuO/TiO2, CuO/Al2O3-TiO2, and CuO/Al2O3 was decreased following exposure of the catalysts to SO2, and this feature was attributed to competition for NH3 between NO and surface sulfate species, the latter involving formation of (NH4)2SO4. V2O3 supported on a composite support featuring 20% AL2O3, balance TiO2, was as active as V/TiO2 for NO redn. by NH3, and the Al2O3 component rendered the catalyst resistant to SO2 poisoning because sulfate formed on V2O5 could be transferred to Al2O3, where it did not interfere with the activity. Catalysts with CuO and V2O5 supported on Al2O3-TiO2 were not resistant to SO2 poisoning during selective catalytic redn. of NO because the Cu component attracted too much SO2 onto the support, thus exceeding the protective capacity of the Al2O3 component. [on SciFinder(R)]Pubblicazioni consigliate
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