Supported Transition-Metal Oxide Catalysts for Catalytic Reduction of SO2 with CO as a Reducing Agent

Abstract

Performances of supported transition-metal oxide catalysts in the catalytic reduction of SO2 with CO as a reducing agent were investigated. According to our study, Fe2O3/γ-Al2O3 was found to be the most active catalyst among eight γ-Al2O3-supported catalysts tested. With Fe2O3 as the active species, CeO2 is the most suitable support. Using Fe2O3/CeO2, the best catalyst, the optimal feed ratio of CO/SO2 is 3:1 and provides the highest yield of elemental sulfur and a higher conversion of SO2. The catalyst presulfied by CO + SO2 exhibits a higher performance than those pretreated with CO, H2, or He. The desorption patterns of CO temperature-programmed desorption (TPD) indicate that Fe2O3/CeO2 is more easily reduced by CO than Fe2O3/γ-Al2O3, while the SO2-TPD patterns reveal that Fe2O3/γ-Al2O3, which is more seriously inhibited by SO2 than Fe2O3/CeO2, adsorbs more strongly a larger amount of SO2. These two facts might be the predominant reasons why Fe2O3/CeO2 has a far higher activity and stability.