Operando XAFS studies of supported copper oxides for catalytic ammonia combustion

Local structures around copper oxides (CuOx) supported on aluminum oxide borates (10A2B) during the NH3 combustion reaction were studied by operando XAFS. Although CuOx in as-prepared CuOx/10A2B at room temperature can be assigned to CuO, the CuO was partly reduced to Cu2O during NH3 combustion at 400°C. In contrast, CuAl2O4 was formed after thermal aging of CuOx/10A2B at 900°C for 100 h in air, local structures of which were preserved during NH3 combustion at 600°C.