Barium promoted manganese oxide catalysts in low-temperature methane catalytic combustion

Abstract

In this study, a series of BaO-MnOx mixed oxide catalysts were synthesized by the mechanochemical method and employed in lean methane catalytic combustion (MCC) at low temperatures. The synthesized catalysts were characterized by XRD, BET, TGA, FT-IR, H2-TPR, O2-TPD, and FESEM analyses. The results indicated that the 10 wt% BaO-MnOx catalyst with a BET surface area of 25 m2 g−1 possessed the best catalytic performance. The higher activity of the 10 wt% BaO-MnOx catalyst was due to the higher ability to supply oxygen through the components during the MCC process. The light-off temperature corresponding to 50% of the methane conversion was about 330 °C, which was about 50 °C lower than the pure MnOx. Moreover, for the BaO(10)-MnOx catalyst, the 10 and 90% of methane conversion temperatures were about 305 and 427 °C, respectively. Also, the 10 wt% BaO-MnOx catalyst exhibited high catalytic stability under dry feed condition at 450 °C for 50 h. Furthermore, the influence of various parameters such as calcination temperature, feed ratio, GHSV, pretreatment condition, and presence of water vapor in the feedstock was studied on the catalytic performance.