Effect of CeO2 support on the selective catalytic reduction of NO with NH3 over P-WiCeO2

A series of CeO2 supports over phosphotungstic acid doped CeO2 (P-WiCeO(2)) prepared by hydrothermal (Cat-A), sol-gel (Cat-B) and precipitation (Cat-C) methods were investigated in selective catalytic reduction of NOx by NH3. The catalytic activity of P-W/CeO2 was dramatically affected by the preparation methods of CeO2 supports. Results implied that the incorporation of W species could cause the decease of cell parameter and lattice contraction, resulting in inducing the formation of more Ce3+ and oxygen vacancies over the Cat-A catalyst, leading to the excellent oxidation ability and SCR activity. Furthermore, the Cat-A catalyst possessed the most amount of Lewis acid sites, resulting in the superior catalytic activity. Besides, the larger specific area and the excellent redox ability were responsible for the outstanding SCR performance. In brief, the favorable activity in NH3 oxidation, as well as NO oxidation, contributed to the excellent catalytic activity. Therefore, the Cat-A catalyst exhibited the best SCR activity and over 90% NOx conversion was obtained at 190-450 degrees C. (C) 2016 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.