Preparation and NH3-SCR catalytic performance of CeTiOx catalysts with different pore structures
-
Graphical Abstract
-
Abstract
To investigate the influence of pore structure on the catalytic activity of catalysts, four catalysts including three-dimensionally ordered macroporous-mesoporous (3DOM-m) CeTiOx, three-dimensionally ordered macroporous (3DOM) CeTiOx, three-dimensionally ordered mesoporous (3DOm) CeTiOx and disordered mesoporous (DM) CeTiOx were synthesized by the sol-gel method. The NH3-SCR denitration testing results show that the performance of the catalysts with different pore structures follows the sequence of 3DOM-m CeTiOx>3DOm CeTiOx>3DOM CeTiOx>DM CeTiOx, and the 3DOM-m CeTiOx shows an excellent catalytic activity, with more than 90% NO conversion in the range of 250–400 ℃ at a GHSV of 60000 h−1 . The characterization of catalysts by XRD, SEM, BET, NH3-TPD and in-situ DRIFTS indicates that the surface area is not the dominant factor determining the catalytic activity of CeTiOx. 3DOM-m CeTiOx has a highly ordered macroporous-mesoporous structure and abundant Bronsted acidic sites, thereby improving the denitrification activity. The NH3-SCR reaction over the 3DOM-m CeTiOx mainly follows the L-H and E-R mechanisms.
-
-