2001 Volume 34 Issue 2 Pages 148-153
Titania-pillared interlayer clays (Ti-PILCs) exhibited peculiar physicochemical characteristics as catalyst supports compared to that of titania for the reduction of NO by NH3. Korean natural bentonite (KNB) was employed as a basic component of PILC due to its high pillaring capacity. For the freeze-dried Ti-PILC, the development of needle-like crystallites revealing the formation of a “house-of-cards” structure by delamination of long-ranged layered structure of Ti-PILC has been observed. Freeze-drying creates a unique pore structure of Ti-PILC catalyst such as multi-modal pore size distribution simultaneously containing micropores and meso- or macropores in the pore network. In particular, V2O5/Ti-PILC catalyst exhibits high performance of NO removal by NH3 mainly due to the strong catalyst surface acidity and redox properties examined by NH3 TPD and TPR-TPO studies, respectively. Without the addition of the catalyst promoter, WO3 and MoO3 to the catalyst, V2O5/Ti-PILC catalyst shows competitive NO removal activity to a commercial one.