Three-dimensional ordered mesoporous CeXZr1−XO2 for selective catalytic reduction removal of NOX with NH3

Abstract

A series of highly ordered mesoporous CeXZr1−XO2 (x represents the mole ratio of Ce), were fabricated for NH3-SCR of NOX using KIT-6 as a hard template, which have been characterized by TEM, XRD, BET, BJH, XPS, H2-TPR, NH3-TPD and in-situ DRIFT, showing superior composite crystal microstructure, uniform mesopore diameter and larger surface area. Among all the mesoporous CeXZr1−XO2 samples (x=0, 0.25, 0.33, 0.5, 0.67, 0.75 and 1), mesoporous Ce0.67Zr0.33O2 showed the best NH3-SCR activity to clean NOX, and 100% NOX conversion ratio at 325°C can be reached, as well as excellent H2O or SO2 tolerance and best thermal stability. Furthermore, the addition of ZrO2 content enhanced the thermal performance and redox ability of mesoporous CexZr1−xO2, which were favorable for their excellent NH3-SCR performance. Finally, a possible redox reaction mechanism of NH3-SCR reaction over the mesoporous CeXZr1−XO2 was proposed.