Simultaneous SO2/NOx abatement using zeolite-supported copper. Annual report, October 1, 1994--September 30, 1995

摘要

During the past year, the research program has taken two different approaches to the study of the simultaneous removal of NO and SO2 from flue gases. One approach is to investigate the adsorption and reaction of SO2 on a copper-impregnated alumina, prepared using non-aqueous impregnation techniques. The second approach is to study the nature of the active catalytic sites for NO decomposition for Cu/ZSM-5. The approach taken is to prepare a series of NO decomposition catalysts using different substrates and different sources of copper, with different copper nuclearities. Catalysts prepared by non-aqueous impregnation using mononuclear copper complexes, copper ethylenediamine perchlorate, on ZSM-5 show modest, sustained activities. The activities are significantly less than those observed from catalysts prepared via aqueous impregnation on the same substrates using copper acetate, but nonetheless the activity is sustained. Copper on silica, prepared using a dinuclear copper precursor, copper bipyridyl dimer, shows some initial activity for NO decomposition, 6%, but that activity decreases in about an hour-and-a half to approximately 1%. Subsequent modeling showed that the precursor could not fit inside the ZSM-5, and that the catalytic activity must have been due to reactions on the exterior surfaces of the zeolite catalyst. The same precursor in Zeolite-Y showed excellent initial activity, near 100% conversion, but that activity decreased rapidly to effectively 0% conversion, apparently due to the catalyst not releasing O2 , one of the reaction products, from the surface. This report reviews the results obtained during the past year, and presents results obtained during the last quarter.