Effect of Manganese Catalysts on the Performance of Anodes in Direct Carbon Fuel Cells

The efficiency of direct carbon fuel cells is higher than that of solid oxide fuel cells. The direct carbon fuel cell transforms chemical energy into electrical energy. In this work, the La0.4Sr0.6MnxTi1-xO3-delta (x = 0.02, 0.04, 0.06, 0.08) anode material has been synthesized by the combustion method to examine the device performance. X-ray analysis confirmed the single-perovskite cubic structure with an average crystalline size of 80 nm. An electrical conductivity of 2.1 S cm-1 and fuel cell performance of 100 mW cm-2 at 600 degrees C are measured with sub-bituminous fuel. Theoretical results describe the minor contribution of manganese (Mn) in the valence band and the major one in the conduction band, and with minimum energy, the Mn electrons may jump in the conduction band. Moreover, density functional theory confirmed that with an increase in the Mn concentration, Mn and Ti energy states appear at the Fermi level, which reveals that the conductivity of the compound has improved, agreeing with the experimental results that the Mn concentration led to the enhancement of the conductivity.