Study on H2O2, Ce, W modified MnOx/TiO2 based NH3-SCR Catalyst: The status and effect of doped promoters and synergies

A series of MnO x /TiO 2 based NO x reduction catalyst was prepared by excessive impregnation method. The catalyst was modified by Ce, W and oxidizing agent H 2 O 2 . Mn-Ce/Ti-H and Mn-Ce-W/Ti-H catalysts exhibit the best low temperature activity (nearly 80% NO x conversion at 155–325 °C) and the widest active temperature range (nearly 80% NO x conversion at 180–420 °C), respectively. Property and structure of the modified catalyst were characterized by XRD, TEM, XPS, H 2 -TPR, NH 3 -TPD, etc. It is found that oxidizing agent H 2 O 2 , as well as the high dispersion and specific surface area, can increase the amount of Mn 4+ , Ce 3+ and active oxygen sites on catalyst surface, and the synergistic interaction between Mn and Ce facilitated redox process of the catalysts. These can improve the low temperature activity of the catalyst by facilitating “fast SCR” reaction. The addition of W increased acidity of the catalyst and improved high temperature catalytic activity of the catalyst.