CeOP material supported CeO2 catalysts: A novel catalyst for selective catalytic reduction of NO with NH3 at low temperature

In this paper, Ce O P material (mainly consisted of CePO 4 ) and TiO 2 supported CeO 2 catalysts were prepared by wet impregnation route for the selective catalytic reduction (SCR) of NO with NH 3 . The SCR activity results had revealed that CeO 2 /Ce O P-0.4 catalyst yielded over than 90% NO conversion within the temperature range of 200–300 °C, whereas the deNO x efficiency of CeO 2 /TiO 2 -0.4 catalyst was less than 30% at 200 °C. After a series of characterization tests, it was found that CeO 2 /Ce O P catalysts were of better dispersion of active phase than CeO 2 /TiO 2 owing to the strong interactions between CeO 2 and surficial Ce O species on Ce O P material. Thus, more active oxygen species could participate in the SCR reaction at low temperature. Furthermore, compared to CeO 2 /TiO 2 sample, the surface acidity was greatly enhanced for CeO 2 /Ce O P catalysts by the introduction of the acidic support, benefiting the adsorption of NH 3 . Both of which were attributed to the main reasons of the promoted SCR performance over CeO 2 /Ce O P catalysts. Moreover, the NO x ad-species on CeO 2 /TiO 2 sample were very stable and could hardly react with adsorbed NH 3 , impeding L-H reaction pathway at low temperature.