Plasma-assisted CuO/CeO2/TiO2-γ-Al2O3 catalysts for NO + CH4 reaction and NO temperature programmed desorption studies

The removal of NO and CH4 has been studied with a hybrid system integrating plasma activation and four Cu-based catalysts. The best catalytic performance was observed for catalysts obtained from CuO/CeO2/TiO2/γ-Al2O3.The efficiency of NO removal decreased with the order: 12%CuO/10%CeO2/15%TiO2/γ-Al2O3 > 12%CuO/15%TiO2/γ-Al2O3 > 12%CuO/γ-Al2O3 > 12% CuO/TiO2. Brunauer-Emmett-Teller (BET), X-ray diffraction (XRD) Temperature-programmed reduction (H2-TPR) and NO temperature-programmed desorption (NO-TPD) experiments were carried out to gain insight into the synergetic effects with the catalysts. The results revealed that copper species existed as bulk CuO crystalline for all the catalysts, H2-TPR suggested that the Cu2+ incorporated TiO2 or CeO2 lattice and crystalline CuO might be the most active component for NO removal, and NO-TPD studies indicated that 12%CuO/10%CeO2/15%TiO2/γ-Al2O3 catalyst had lower NO desorption temperature and larger peak area, which seemed to be responsible for the better catalytic activity over NO + CH4 reactions than other catalysts.