Catalytic performance of acidic zirconium-based composite oxides monolithic catalyst on selective catalytic reduction of NO_x with NH3

摘要

A series of monolithic acidic zirconium-based composite oxide catalyst (Ce-ZrTiSiWO_x) were prepared by different introduction methods and loading contents of CeO2 for selective catalytic reduction (SCR) of NO_x with ammonia. In this work, a acidic zirconium-based composite oxide (10 wt.% CeO2/ZrTiSiWO_x) catalyst prepared only by impregnation method presented good NH3-SCR activity and high N2 selectivity in a broad operation temperature window, comparative strong tolerance of gas hourly space velocities (GHSV), water, sulfur and hydrothermal aging. Compared with V2O5/TiSiWO_x and Fe-ZSM-5 catalysts, the CeO2/ZrTiSiWO_x catalyst showed a better NH3-SCR performance and higher thermal aged performance. More than 80% NO_x could be removed in the temperature range of 277-545 °C under GHSV of 30,000 h_(-1) over the monolithic 10 wt.% CeO2/ZrTiSiWO_x catalyst. More surface atomic concentration of Ce, strong reducible ability and the maximum acid amount are important reasons for the high NH3-SCR activity of the CeO2/ZrTiSiWO_x catalyst.