Ag-modified SmMn2O5 catalysts for CO and C3H8 oxidation

A series of Sm-Mn oxides (SmMnO 3 , SmMn 2 O 5 and Sm 0.9 Ag 0.1 Mn 2 O 5 ) of perovskite-type and mullite crystal phases were synthesized for the catalytic oxidation of CO and C 3 H 8 . The Sm 0.9 Ag 0.1 Mn 2 O 5 composition showed the highest catalytic activity among the series of solids, especially for the CO oxidation to CO 2 with T 50 and T 90 values of 60 and 95 °C, respectively. The catalysts were characterized by powder XRD, Raman, BET, XPS, and H 2 -TPR. It was found that the catalytic performance of the solids was correlated well with their redox properties. Synergetic effects between Ag-related species and the mullite phase resulted in more active surface oxygen species and remarkably lowered the reduction temperature of the Sm 0.9 Ag 0.1 Mn 2 O 5 solid.