Crucial role of titanium dioxide support in soot oxidation catalysis of manganese doped ceria

• Published in: Catalysis science & technology 2017, Vol.7 (14), p.3045-3055
• Main Authors: Mukherjee, Deboshree, Venkataswamy, Perala, Devaiah, Damma, Rangaswamy, Agolu, Reddy, Benjaram M.
• Format: Article
• Language: English
• ISSN: 2044-4753; 2044-4761
• DOI: 10.1039/C7CY01029J

The influence of an anatase-TiO 2 support on the diesel soot oxidation catalytic activity of manganese doped ceria is investigated. The soot conversion light-off temperature is significantly lowered with the application of anatase-TiO 2 as the support in comparison to the unsupported and γ-Al 2 O 3 supported CeO 2 –MnO x catalysts. Additionally, considerable enhancement in bulk and surface defects is observed for CeO 2 –MnO x /TiO 2 , which is attributed to the promotional role of the CeO 2 /TiO 2 interface in the formation and stabilization of defect sites. The temperature programmed desorption of oxygen (O 2 -TPD) study of CeO 2 –MnO x /TiO 2 indicates a sharp increase in oxygen desorption after a temperature of 500 K. In good correlation, the diesel soot conversion substantially increases after 550 K, but below this temperature the TiO 2 supported catalyst exhibits comparable activity to that of the γ-Al 2 O 3 supported catalyst. Increased oxygen mobility at elevated temperatures might play a key role in the performance of the TiO 2 supported catalyst. Moreover, its structural stability and appreciable catalytic activity were retained even after high temperature annealing treatment.