Catalytic Combustion of SOFC Stack Flue Gas over CuO and Mn2O3 Supported by La0.8Sr0.2Mn0.67Cu0.33O3 Perovskite

An efficient oxidation catalyst was developed to increase the combustion efficiency of unreacted CO, H-2, and CH4 in flue gas of solid oxide fuel cell (SOFC) stack. Amorphous Cu-Mn oxide catalyst (CuMnLa/Alumina) showed high catalytic activity, but significant degradation occurred due to phase transition to spinel structure at high temperatures (T > 650 degrees C). La0.8Sr0.2Mn0.67Cu0.33O3 perovskite (LSMC(p)) supported CuO or Mn2O3 exhibited improved thermal stability than CuMnLa/Alumina catalyst. Especially in case of 50Mn/LSMC(p), after the catalyst was exposed to 800 degrees C for 24 h, T-50 of CO, H-2 and CH4 was achieved at 170, 230, and 600 degrees C, respectively. This result is much lower than that of CuMnLa/Alumina, which was exposed to the same condition. The high combustion efficiency is due to retention of the Cu2+-Mn3+ redox couple, and supply of lattice oxygen from LSMC(p), especially at high temperature. (C) 2017 American Institute of Chemical Engineers