Cavity size dependent SO2 resistance for NH3-SCR of hollow structured CeO2-TiO2 catalysts.

CeO 2 -TiO 2 hollow spheres with distinct cavity sizes of ca. 500 nm and 5 μm were prepared from carbon spheres and hybrid Ce–C sphere templates, respectively. After 40 h of successive operation in SO 2 -containing gas stream for the NH 3 -SCR reaction, the catalyst with large cavity showed only 4.7% activity loss, while that with small cavity exhibited sharp decrease (ca. 72.6%) in its deNO x activity. Results of physicochemical characterizations manifested that accelerated decomposition of NH 4 HSO 4 on the CeO 2 -TiO 2 catalyst with larger cavity size is likely largely responsible for the improved SO 2 resistance of catalyst activity loss. Hollow structured CeO 2 -TiO 2 yolk-shell catalyst with larger cavity exhibited superior SO 2 resistance due to accelerated NH 4 HSO 4 decomposition. Unlabelled Image • CeO 2 -TiO 2 hollow structured catalysts with different cavity sizes were prepared. • CeO 2 -TiO 2 catalyst with larger cavity showed remarkably enhanced SO 2 resistance. • Accelerated decomposition of NH 4 HSO 4 is account for improved SO 2 resistance. [ABSTRACT FROM AUTHOR]