(138a) Highly Efficient SO2 Removal By Supported Manganese Sorbents for SOFCs Cathode Protection | AIChE

(138a) Highly Efficient SO2 Removal By Supported Manganese Sorbents for SOFCs Cathode Protection


Cheng, P. - Presenter, Auburn University
Tatarchuk, B. J. - Presenter, Auburn University
Chi, M. - Presenter, Auburn University

Because of high energy efficiency and fuel flexibility, Solid Oxide Fuel Cells (SOFCs) are promising energy converting devices nowadays. However, researchers realized that SO2 can cause a rapid degradation by interacting with cathode side materials. In logistic solid oxide fuel cell systems, the sources of SO2 mainly arise from high sulfur-containing marine fuels, such as JP-5 and JP-8. Therefore, the cathode protection for SOFCs is a vital consideration for the power system. In this study, dispersed manganese oxides on supports such as ZrO2, SiO2, γ-Al2O3, and TiO2 were prepared by a method of incipient wetness impregnation (IWI). The breakthrough performance was evaluated in a conventional fixed-bed sorption system. Effects of precursor materials, supports, manganese loadings, and calcination temperature on the sorbent performance were investigated in details. A combination of various surface science techniques, including XRD, N2 physisorption, O2 chemisorption, H2-TPR, and XPS, were applied to characterize the chemical environment of the adsorbents. The highest saturation capacity was obtained by using 5 wt.% Mn supported on ZrO2. XRD and O2 chemisorption results demonstrated that MnO2 and Mn2O3 co-existed in well-dispersed forms at 5.0 wt.% of Mn on ZrO2. It was also found that the amount of manganese in sorbent has a remarkable influence on the oxidation state of manganese. In addition, XPS results revealed that the performance of Mn-doped adsorbent was strongly dependent on the population of surface terminal hydroxyl groups.