Catalytic combustion of SOFC stack flue gas over CuO and Mn2O3 supported by La0.8Sr0.2Mn0.67Cu0.33O3 perovskite

Abstract

An efficient oxidation catalyst was developed to increase the combustion efficiency of unreacted CO, H2, 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°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°C for 24 h, T50 of CO, H2 and CH4 was achieved at 170, 230, and 600°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. © 2017 American Institute of Chemical Engineers AIChE J, 64: 940–949, 2018