Study On Effect Of Fe On The SCR Of NO Over Cu/Sepiolite

This topic for study is that a series of Cu/Sepiolite and Cu/Fe/ Sepiolite adulterated iron catalysts were prepared by equal volume impregnation with the sepiolite modified by hydrochloric acid as support, Meanwhile, The catalytic activity for NO reduction by C₃H₆ was evaluated under rich oxygen conditions. Moreover, the means of XRD, BET, SEM and XPS were used to characterize these catalysts and the factors affecting the activity of catalysts were discussed.The activity experiment shows that Cu/Sepiolite with copper content 5%(wt.) has better activity over NO reduction among the series of catalysts with the temperature range of 240～350℃. The catalytic performance of Cu/Sepiolite over NO reduction was improved because of the addition of Fe. The addition order and quantity of Fe take further effect on the catalytic activity. The catalytic activity of Fe/Cu/Sepiolite catalyst which is prepared with Fe being loaded on Cu/Sepiolite catalyst is better than that of Cu/Fe/ Sepiolite which is prepared with Cu being loaded on Fe/Sepiolite catalyst. The catalytic activity of Cu-Fe/Sepiolite catalyst is worst among three kinds of catalysts which Cu and Fe elements are loaded on Sepiolite support. The activity experience shows that the addition quantity of Fe is a important factor to have an influence on the catalytic activity. When the mol ratio of Cu and Fe is 1:3, the activity of catalysts is best, next is 1:2. GHSV is also a important factor to the the activity of catalysts, the heavier it is, the catalytic activity is lower.From SEM and BET results, it was found that the modified sepiolite has larger surface area in comparison with the natural sepiolite from 57.5540m²/g to 127.5011m²/g. the samdwich and catemarian framework character is in evidence. Furthermore, the whole framework has not been changen at the temperature of 350℃, which indicates that sepiolite has thermal stable properties. The addition of Fe makes other active elements be loaded on the surface and in the apertures of catalysts in average. From XPS analysis, it was estimated that forms of Cu are CuO and Cu₂O and that of Fe is Fe₂O₃ on the surface of catalysts. From data of XRD, The addition of Fe makes some atoms order of sepiolite crystal change.In this paper Cu/Sep catalysts were prepared with the addition of Fe and studied the catalytic performance for NO catalytic reduction, this study were not only enriching the theory of copper catalyst but also exploiting a new catalyst, in addition these copper catalysts as new catalysts offered new choose and new technology approach for environmental protection.